26.09.2012 Boka Reflux Still - How To Build - Distillers Wiki Boka Reflux Still - How To Build From Distillers Wiki The Bokakob (Boka or Bok for short) is the common name for a Dual Slant-Plate Single Column In-line Reflux Still designed by Alex Bokakob in 2001. The still was originally designed with a fairly small reflux column to sit atop a stove-top boiler, and has seen significant modifications and improvements over the years. This still is popular with many novices for its simplicity to build and operate, while being able to yield 95% ABV neutral spirits. It can also have its packing material removed and function as an adequate pot still. It is classified as a Liquid Management or LM Column reflux still. Contents 1 History 2 Column and Slanted Plates 3 Condenser 4 Boiler 5 Heat source 6 Column packing 7 Thermometer 8 Output Tube & Needle Valve 9 Safety considerations 10 Cleaning and prep for use 10.1 Post-build cleaning runs 11 Operation instructions 12 Optional extras 12.1 Detachable head 12.2 Reflux centering The original Boka photo and plan specs History Bokakob created a series of reflux still design drawings that were widely circulated after they were created in 2001.[1] (http://homedistiller.org/photos-alex.htm) This particular still featured a short (2ft/.67m) column made of 1.5" copper pipe attached to a stove-top pot boiler, and only required three joints to be soldered (the upper and lower plate, and take-off tube). Various discussions on Yahoo and HomeDistiller.org resulted in many design variations and improved efficiencies. The still was named after its designer Alex, who had a Yahoo username of Bokakob, but web discussions with poor spelling or simple abbreviation led many to refer to the still as a Bokabob, Boka and Bok. Column and Slanted Plates wiki.homedistiller.org/Boka_Reflux_Still_-_How_To_Build 1/18 Don't forget to look at connectors which can be harder to procure than pipes.org/forum/viewtopic.php?f=15&t=18093) Your column should ALWAYS be properly vented and no pressure buildup should be possible. and copper actually assists in creating a clean flavor in the final product by removing sulfides as vapors come in contact with the copper as they travel through the column. Synthetic materials other than PTFE are unsuitable.php?f=35&t=5090) Most pipe also comes in varying thicknesses: K.[[8] (http://homedistiller.php?f=2&t=749&start=0) A Great Diagram of a Boka by Samohon Availability and local price will probably be the greatest determiner of which material to use. but the cost of materials increases exponentially and availability diminishes. With a wider column.org/forum/viewtopic. M is the thinnest and is a better value of pipe for our purposes. This will impact the condenser and boiler sizes you need.How To Build .sizes. and the overall yield of properly refluxed distillate will increase.org/forum/viewtopic.org/forum/viewtopic. which is the basis of the reflux design) or be drawn-off for collection. 3" copper male and female screw adapters are pretty rare. but may make attachments more difficult to fit. all other things being equal.php?f=17&t=18926) ] A 3" (76 mm) column allows for even more speed.5" (38 mm) column. and is usually impacted by costs and local availability. so insulation is less critical. regardless of the thickness of the pipe. DWV (which stands for Drain Waste Valve) is the thinnest by far. The first decision you'll make when making a Boka is usually the width of your column.5" (38mm). [3] (http://homedistiller. and subsequently cheapest and best value.org/Boka_Reflux_Still_-_How_To_Build 2/18 . L. etc that are sold retail.) The most common and recommended size for simple hobby distillation is a 2" width.org/forum/viewtopic. If you are going to use DWV. even in full reflux.homedistiller. (ie.09. choose the copper.Distillers Wiki General Theory The single in-line reflux column of the Boka is meant to carry vapors from the boiler up through packing material for reflux and up to the condenser. L is the most common and is a standard thickness. the heat put into the still has to be lower to keep the vapor speed in the column at an appropriate speed so the reflux can occur properly. The width of the column directly impacts the speed at which distillate can be collected. made sure that you check the accompanying fittings before you buy to make sure it will all assemble easily and be solderable.org/forum/viewtopic.htm) K is the thickest but is commonly not found at retail outlets. meaning that it fits the couplers.php?f=2&t=3662) See rule #8 [4] (http://homedistiller. with a narrow column.php?f=46&t=18123) [6] (http://www. A 2" column will allow wiki.homedistiller. All other things being equal.26. Some of the distillate will fall to the dual slanted plates which can then overflow (allowing the distillate to fall back into the packing. it has temperature and pressure ratings and warnings which do not apply to our neutral pressure systems [7] (http://homedistiller. Also note that well polished copper is very pretty. M and DWV. [5] (http://www. Materials The column of your still should be made from copper or stainless steel. Stainless is inert.2012 Boka Reflux Still . more heat can be applied while maintaining proper vapor speed. Due to its thin walls. [2] (http://homedistiller.com/materls/pipeCopper. In actuality. Stainless does not suffer as greatly from heat loss. If you have pressure buildup in your column it could explode. Many Boka builders quickly realized that a 2" (50mm) column yielded almost twice the distillate as the 1. Also note that stainless steel may require more industrial type of equipment and skill to weld than copper which requires simple soldering. Column Width The original Boka was built with a 1. caps. and was still reasonably cost effective. until you run into the 50"-60" (125cm. but they break down quickly when diameter changes to other values. These are accurate in a 2" column. but distillate was wiki. It is possible to make the column shorter than that. Samohon's Blueprint of the Slanted Plates on a Boka The ideal placement for the plates should be such that the upper plate is just below the condenser.htm) . beyond which there is little benefit building taller.homedistiller. A taller column allows for more packing material. and if you have the space and money for the materials. Some people like to talk about column height in a ratio with column diameter. The recommended column height to width ratios for a 2" column are between 12:1 to 30:1. the next step is to figure out how much pipe you'll need. about 0.org/forum/viewtopic. The recommended packed height of a reflux column is 48" to 60" (120cm to 150cm).2012 Boka Reflux Still . Column height One you've figured out which width of pipe you are getting. All else being equal. and ceiling height also becomes an issue. The lower plate is angled towards the wall of the column and collects a "pool" of distillate. The packed height (the amount of column height taken up by packing) of the column directly impacts the purity of the distillate you are able to produce. This allows for further reflux and purification of the distillate.Distillers Wiki for around 1 to 2 quarts or litres output an hour. but are very slow to run at those purities. and spacing The slanted plates (not to be confused with reflux plates or trays such as bubble caps or perforated plates discussed elsewhere) in the Bokakob design are set at an angle below the condenser coil so that the upper plate collects distillate from just over half of the column and directs it onto the other lower plate. You can build it as short as you like. which allows more distance for the vapour to travel while mingling with downcoming reflux and form a temperature gradient. (depending on column height and desired purity) while a 3" column can almost double that. it is better to have a taller column. tails). the capacity of the column to produce high alcohol distillate is reduced.php? f=17&t=15467&start=15) For some detailed expaination on the theory behind how packing height and reflux influences column efficiency. [10] (http://homedistiller. which means higher alcohol content in the distillate and better separation of undesirable fractions (heads.they are independent variables [9] (http://homedistiller. and reflux would need to be increased to maintain pure output. the "pool" overflows and a notched recess in the lower plate allows this overflow to fall back into the middle of the packing material of the column below. placement.org/reflux_calc.150cm) range. In earlier designs the upper plate was connected to the bottom of the condensing coil.org/refluxdesign. and also mislead new distillers into thinking that wider columns require more height . Plate angle.5" to 1" (15-25mm). plus another 8-10" (20-25cm) for the plates and condenser.org/forum/viewtopic. however.org/Boka_Reflux_Still_-_How_To_Build 3/18 . Columns with as little packed height as 12" (30cm) can still achieve near azeotrope.09. which will slow down operation. At the bottom of the "pool" there is a take-off tube which can be opened to collect the distillate. but as the packed height is reduced. If the take-off tube is only partially opened or is left closed. [12] (http://homedistiller. The interactive design calculators are especially useful for determining how your still will behave and where it's theoretical performance limits lie.How To Build .php?f=17&t=15467&start=60) .26. Beyond that there is very little benefit in additional packed height.htm) Most 2" (50mm) columns would have between 36" (90cm) and 50" (125cm) of packed height. and also varies with different packing materials read more at the reflux still design page on the Homedistiller parent site [11] (http://homedistiller. php? f=2&t=8794) Templates For those who don't want to go through the trouble of measuring and marking their column with the proper placing of the plates. You also need to ensure that both plates pass the center of the column.75 to 1" (1725mm) is best in a 2" (50mm) column. Others have found success using a hacksaw or two hacksaw blades side by side to accommodate the width of the plates. mitres and saw box Cutting the slanted plate grooves in the column can be difficult. the rectangular plates can be inserted into the grooves and marked with the correct shape. which is cut along its edge )parallel to direction of the pipe) and beaten flat with a hammer. Once the column has grooves cut to accommodate the plates.php?id=2468&mode=view) The plates are typically made from a scrap section of copper pipe.php?f=17&t=17857&start=26) [15] (http://homedistiller. ensure that your printer isn't scaling the image at all.php?f=17&t=1757&start=15) More extreme angles (>30º) will require more material to construct and will not provide any benefit.org/forum/viewtopic. If you are using a template or your column has been pre-marked with the desired cut locations. These can be printed and taped to your column in the proper position and the cuts can be made through the template. There is no need to pre-cut the plates into elliptical shape before the grooves have been cut.How To Build .Distillers Wiki able to drip down the sides of the column and then would not properly mingle with upcoming vapour. or overlap in a vertical plane. If you are lucky enough to have a chop saw with a compound mitre box. [13] (http://homedistiller. The angle of the slanted plates has traditionally been at 30 degrees of angle from horizontal.2012 Boka Reflux Still . The general consensus is that 0. A standard mitre box will not work since you need the angle to be cut around a different axis than a standard mitre box can provide. several generous souls have created easy to use templates that are pre-marked with the proper plate positions for a 2" column.org/forum/download/file. So. Too small of a space may increase vapor speed in the column after the constriction and minimize the time the vapor spends condensing at the condenser coils.php?id=7005) Cutting. If your plates do not overlap then distillate will fall of the upper plate back into the column.09. the vertical space that is left between them) needs to be sufficient to not constrict flow of vapor up the column. you may be able to cut the grooves with that. while you need to wiki. Later designs have the upper plate soldered to the column independent of the coil. missing the lower plate and collection "pool". Building your coil and deciding its placement and measuring where it will end in the column need to be completed before deciding on placement of your slanted plates. The original design also required the condenser/plate assembly be perfectly rotated to align with the lower plate or collection would suffer. This link is to a revised 2010 template [18] (http://homedistiller.php?f=32&t=15948) There is a nice diagram of the Boka head here. The spacing of the plates.org/forum/viewtopic. For a 2" column.org/Boka_Reflux_Still_-_How_To_Build 4/18 Pikluk's Boka Head . or shrunk down for smaller columns. you need to know the size of your condenser coil. then ground or cut to be smooth. though those using a compound mitre box may only have a 45º slot.26. [16] (http://homedistiller.org/forum/viewtopic. (ie. They can be scaled up 50% for a 3" column. [14] (http://homedistiller. you can use a Dremel or hand-drill with a black Dremel cutting wheel to cut the column grooves. The angle is only important to the extent that the take-off tube is submerged in the "pool" of distillate. This approximates the cross-sectional area of the column with the packing material in place. [17] (http://homedistiller.org/forum/viewtopic. (A normal one only allows 'yaw'.org/forum/download/file.homedistiller. Once to proper shape they can be soldered or brazed into place. for proper placement of the slanted plates. Skip to next section and build a condenser. It is commonly referred to as a 'double helix' coil. As the boiler is heated.org/forum/viewtopic. Measure and cut the grooves for the slanted plates just below the condenser. you may need to install the lower plate first.org/Boka_Reflux_Still_-_How_To_Build 5/18 .org/wiki/Condenser_%28laboratory%29) It is constructed from one continuous piece of copper tubing. but isn't too difficult with some practice and simple household tools. Measure the height of the condenser installed on the column and mark your column. wiki. Check to ensure the slanted plates overlap inside your column. Both the input and output are at the top of the coil. You probably want to solder each plate and its corresponding tube at the same time so you don't melt nearby solder.php?f=11&t=1689) Keep in mind that filling your coil with salt will greatly minimize the risk of kinking the coil. but many users have found removing the salt after coiling difficult or impossible without high pressure. [21] (http://en.datafilehost.Distillers Wiki adjust the 'roll') [19] (http://homedistiller. Pikluk's un-assembled Boka head Condenser General theory A condenser is a section of coiled tubing (usually copper. the Dimroth Condenser. and only then install the upper plate. if you don't want to buy a spring-style coil bender. and then continued into a second larger spiral wound outside the original spiral back upwards.How To Build .html) An alternate method is featured here which uses a jig and more tools: [23] (http://www. [20] (http://homedistiller. Check your soldering to ensure the column has no leaks and the output tube functions properly. or its proper name.e. DixieDrifter's example of a common dual-wound condenser coil.php?f=17&t=5829&start=165) Summary of building process Find a suitable pipe for your column of proper width and length for your needs.2012 Boka Reflux Still .org/forum/viewtopic.artisan-distiller.php?f=2&t=5810) It is better described as a single-path double-concentric counter-wind condenser. Concentric dual-coil This is the most popular type of condenser used in a Boka. which would be both wasteful and potentially dangerous (i.09.26.) Drill holes for temperature port and output tube and solder them into place.com/download-44b26f83. many spring door stops fit 1/4" tubing and work just as well. but occasionally stainless) which has coolant running through it. which is wound in spiral downwards. There is a great tutorial by Hookline on how to wind this condenser by hand here: [22] (http://www.homedistiller.net/phpBB3/viewtopic.wikipedia. flammable vapors near a heating source). This coolant reduces the surface temperature of the coil which is placed inside the top of the column. they condense to a liquid and fall back down the column where they are collected by the slanted plates for takeoff or return to the column. Also. vapors begin to rise through the column.. When these vapors come in contact with the condenser. then bend down its reflux drip tab. It is more difficult to make than a single coil. To function correctly the condenser must be of such a size or temperature that none of the vapors can exit the column as a vapor. though it is not. then install the plates and solder into place. (If you are using later plate designs. a 6" (150mm) condenser is ample: [29] (http://homedistiller.4mm) copper tubing for every linear inch of wiki.homedistiller. the cold finger also Rudi33's Dual-Concentric increases surface area in the coil and increases efficiency. The Boka can run perfectly fine without any cap or lid above a suitable condenser.org/wiki/Condenser_%28laboratory%29) which is constructed from a single piece of copper tubing which runs straight down to the bottom of the coil with no winds and is then coiled in a spiral around the central tube back upwards. there may not be adequate outlet for the pressure inside the column which would eventually lead to catastrophic failure of the column and/or rapid release of vaporized ethanol near a heat source. A true double-helix with a cold finger is among the most efficient condensers. [26] Coil with a cold-finger (http://homedistiller.org/forum/viewtopic. both of which can cause serious injury or death.php?f=15&t=17456&start=0) It requires more tools. If the condenser is of adequate size and temperature it will condense all of the vapors and no cap or seal is needed at the top of the column. For most applications. you should plan on about 8-12 (200-300mm) inches of 1/4" (6. skill and soldering but yields a superior condenser.2012 Boka Reflux Still .homedistiller. The solution is to have a cold-finger run down the center of the coil.html) Using a cold finger For either of the above designs. a double coil may not be able to be wound narrow enough to fit in the column.datafilehost. and is pictured here: [27] (http://www.wikipedia. A cold-finger is a larger diameter tube down the center that is soldered to the outer coil or coils so that it also carries the flowing coolant. just skipping the first half: [25] (http://www.php?t=2535) Sealed/capped The condenser needs to sit inside the top of the column in order to condense the rising vapors into distillate that can be collected. creating a uniform spiral path for upward airflow in-line with the coils of the condenser.org/forum/viewtopic.com/download44b26f83. If you use a cap it is critical to ensure that it has enough vent holes that so the column cannot build pressure.php?f=17&t=16225&start=0) When calculating the length of tubing needed to create a concentric dual-coil condenser for a standard 2" (50mm) column.org/forum/viewtopic. Many builders use a cap to hold the condenser perfectly in the center of the column. cutting.Distillers Wiki Single coil For columns narrower than 2" (50mm).09. In addition to reducing back-pressure.org/forum/viewtopic. a long coil can create substantial back pressure which may inhibit the ability to use coolant circulated by a pump. Width/size A 6"(150mm) condenser in a 2"(50mm)column is strong enough to condense all of the water vapor put off at full boil of plain water from 2400 watts of heat.php?f=17&t=15762&start=6) If you do not vent the top of the column. especially with columns larger than 2" (50mm) Keep in mind that it may be difficult to fit a cold-finger inside the traditional dual-coil used on a 2" (50mm) column. or to better distribute the weight of coolant lines coming to the condenser. This type of coil can be constructed using the same methods as the dual coil. and accordingly many disillers leave the still open at the top.How To Build . which requires more condensing power than ethanol at regular distilling temperatures. For smaller columns a single coil may fit better. [28] (http://homedistiller.org/Boka_Reflux_Still_-_How_To_Build 6/18 Nuddy's single-wound condenser coil .26. This is a Friedrichs condenser [24] (http://en. the coldest part of the coolant should enter the top of the coil and exit through the center line or cold finger. bathtub.4mm)tubing.php?f=17&t=12217) The condenser should be wide enough to fill the majority of the column. Wider tubing can be used though it is more difficult to bend and is less efficient at heat transfer than smaller 1/4" (6.org/forum/viewtopic.org/forum/viewtopic. [31] (http://homedistiller. or that part which carries out the water. Some forethought might be needed to keep heavier tubing from bending condenser lines that exit the column parallel to the ground. but varies based on the space between the each turn of the coil. (Ie. should closest to boiler. Coil efficiency You can test your coil is working correctly by holding a glass mirror above the coil during operation and looking for condensation on the mirror. is the coldest part of the condenser should be furthest away from the boiler. 2.How To Build .php?f=17&t=6987) Some distillers also opt to route the hot coolant wiki. Add surface area to your condenser. Water temperature in the storage tank also impacts the amount of water the pump must recirculate (Ice can be added to a tank to keep water cold as it re-circulates through the system. For those with re-circulating systems this might mean changing water more often or adding ice to your holding tank. cost of water disposal. you can increase the condensation rate in four ways: 1.org/Boka_Reflux_Still_-_How_To_Build 7/18 .homedistiller.09.) A marine bilge pump or sump pump can be purchased at many local hardware stores or marine supply stores. If your coil is in place and running. pool) and pumped through the condenser using a pump. The right way. Pressure/pump If you are using municipal water for your coolant water supply. there should be no issues with pressure regardless of your type of condenser. though the increase in efficiency for a dual-coil is minimal. Be sure you have your condenser water lines hooked up the 'right' way. You can increase the flow rate of the coolant. or simply water availability. You can also check the temperature of the coolant exiting the condenser to gauge its efficiency. Connection to water source The connection between your condenser and your water source will depend largely on your water source. bucket. and exit the inner coil. If you are using municipal water from a hose. 9 feet (3m) of tubing will yield about 7" (175mm) of dual-coil condenser. If you are using a recirculating pump. This flow is the 'opposite' direction of the vapor flow. The size of the pump needed largely depends on the type of condenser (back-pressure created by dual-coil condensers without cold-fingers can be double that of single coil or cold-fingered coils. but not so wide that it contacts the walls of the column which could warm it and drop its efficiency. Those users may choose to use a recirculating system in which coolant is stored in a tank (Ie: barrel. Do NOT use a flame to test for full vapor condensation. and the warmer part of the condenser. For a single coil or a coil with a cold finger. the coldest water should enter into the outside coil. Because the coolant does not come in contact with the distillate. then the pump tubing will have to be adapted to your condenser tubing. Special care should also be taken to ensure the coolant out line cannot kink and shutoff water flow when it warms up and softens. any type of tubing can be used for the condenser input and output.) [30] (http://homedistiller. which keeps the condenser more efficient along its entire length. as there is significantly lower backpressure. then you can install a 'garden hose to 1/4" compression fitting' to the input of the condenser.26. 4. plus the input and output tubes. Wider tubing can however be of benefit to those planning on using a pump to recirculate coolant. Simply bending the lines towards the ground after exiting the column should be enough in most applications. 3. Faster flow rates introduce more coolant and minimize coolant temperature increase. including various plastics. Many users find that running water through a condenser for several hours can use more water than desired due to cost of water. You can lower the temperature of the water or coolant entering the system. It is easy and cheap to put a pure copper scrubber into the center of the coil where the largest void is which maximizes condenser contact to vapors and minimizes unobstructed airflow through the middle of a condenser with no cold finger.Distillers Wiki dual-coil condenser desired.2012 Boka Reflux Still . In a dual-coil. Attach any hardware needed to hold the condenser in place on the column and add hardware to connect the condenser to a coolant source and coolant output tube. It is important not to overpower the column. reducing the need for a large cooling reservoir.net/photoalbum/main. and reboil.you can see the initial vapour composition by drawing a line across the water-ethanol phase diagram (http://www. Boiler Main Article: Boiler Choose a boiler that meets your budget. Summary of building process Determine the style of condenser that will fit your column.gif&var2=0_0) . Soak in dilute vinegar to clean it and make it pretty. a pot still). empty and clean. Heat source Main Article: Heat source The entire still operation depends on the contents of the boiler being boiled so that vapors can rise up the column. and available tools.Distillers Wiki through a heat exchanger such as an automotive radiator.How To Build .09. checking for fit in your column. This heat can come from a kitchen stove for a small Boka (however there will be problems with the elements cycling on and off too coarsly). Column packing General theory Vapors moving from the boiler through the column to the condenser would exit the still in the same composition as they boiled off in the boiler at if the column was completely empty (i.2012 Boka Reflux Still . Check the condenser to ensure it has proper flow and isn't kinked closed. or modify it so it will be easy to perform these tasks. and at worst the still could choke and puke. condense. with the lower boiling point fractions (like heads components or ethanol) reboiling more readily and rising to the top of the column near the takeoff point. so a 3" will need roughly double that.org/Boka_Reflux_Still_-_How_To_Build 8/18 . The heat input required for efficent operation depends on the diameter of the column. Use the guides above to wind your condenser to the proper shape and size. but more is needed for larger columns in proportion with the increase in the area of the column. or back in the boiler. It is desirable to be able to be control heat somewhat finely.artisandistiller. To achieve higher purity ethanol than this initial vapour has. while a larger Boka is usually heated by a standard propane burner or an electric heater element installed inside the boiler. reflux needs to occur via a repeated condensation and reboiling inside the column. acting as a whole series of pot still distillations. needs and local availability that will be easy for you to fill. Packing material is inserted inside the column to provide surface area upon which downcoming cool reflux and upcoming hot vapour can mingle. and also how we keep taking pure hearts while suppressing tails components like fusel oils. 2000W is sufficent for 2" (50mm) columns.26.homedistiller. Make sure it is stainless steel (or copper). as at best it will wreck the packing's effectiveness. Make any modifications necessary and connect the column. There is good detail on the theory and implications of this on the parent site reflux design section wiki. pushing large amounts of hot liquid out the top of the column.e. parts ability. This is how we concentrate heads for extraction. This cycle is continued up the column.php?cmd=image&var1=pint_o_shine%2Falcoholvapor. and the higher boiling point fractions like fusel oils or water end up in the lower part of the column. htm) . In small-scale distillation.amphora-society. Theoretical plates The amount of purity that a column can produce is directly linked to the type of packing used (amongst other factors).org/reflux_calc. Many scrubbers can be Scrubbers coated with the right material.com/Structured-PureCopper-Mesh-Column-Packing--1-pound_p_6. can be calculated. It should be easy to clean.org/forum/viewtopic. or release impurities or undesirable chemicals into the column. and above all.org/Boka_Reflux_Still_-_How_To_Build 9/18 .htm) on the parent site]. In simple terms. dissolve. Packing material must be something that won’t compress too much.php?f=41&t=1107) [34] (http://homedistiller. The "height equivilant to a theoretical plate" or HETP which you may come across refers to how much column height is needed to make up one theoretical plate. don't use it.htm) . Materials must also have as large a surface area as possible. but the number of stages of reflux. If a magnet sticks to a scrubber. melt. other materials are more practical. There are many discussions linked here on different brands that have proven to be pure: [32] (http://homedistiller. which is usually far more cost effective than having to buy lots of scrubbers.org/refluxdesign. and at the same time offer as little resistance as possible to the gas and liquid flows inside the column. lowest) HETP. While the calculations for calculating theoretical plates are complicated (for details. You can find this out for your still design with the parent site's interactive design calculators (http://homedistiller.com/Copper-Mesh-P947C94. Scrubbers or mesh are the most desirable commonly used packing material.brewhaus. known as structured copper packing. see the HETPequations (http://homedistiller. Is is essential that they be made from either pure stainless steel or pure copper. the greater the surface area of the packed material inside the column.org/equations. but have steel inside and will quickly rust or disintegrate upon repeated use.org/forum/viewtopic. along the reflux calculators that can help you compare packing materials (ie. and eventual replacement. Scrubbers or mesh should be copper or stainless steel.php? f=17&t=13232) Some brewing supply companies like The Amphora Society (http://www.php?f=17&t=4552) [35] (http://homedistiller. as they achieve the best (i.org/forum/viewtopic.org/refluxdesign. Scrubbers and structured mesh Common household pot-scrubbers are one of the most efficient materials that can be used for packing. but will need cleaning occasionally. while copper has the benefit of aiding the removal of sulfides from the product. calculating your height equivilant to a theoretical plate). An amazingly detailed discussion of packing materials can be found on the parent site (http://homedistiller. burn. and therefore how many theoretical plates there are in your still is packing surface area.09. wiki. and without the uncertainty about composition the materials that you have with scrubbers. You can hold a magnet against a scrubber to quickly and easily test if it has steel inside. Stainless has the advantage of not degrading. the more iterations of condensing and reboiling can occur. and is more or less a measure of how well your packing is working. the key factor influencing "height equivilent to theoretical plate". or theoretical number of plates.How To Build . These stages of reflux are referred to as theoretical plates as they occur inside a packed column.e.php? f=15&t=14990) [33] (http://homedistiller.htm) . it should not settle or pack down in the column.26.aspx) also carry copper scrubber-like material.2012 Boka Reflux Still .Distillers Wiki (http://homedistiller.homedistiller. In many commercial stills. these stages are separated by actual physical plates or trays.org/forum/viewtopic.html) (who also ship worldwide quite cheaply) or Brewhaus (http://www. and they are easily found at many home retailers. thus allowing for better cuts.groups. or to assist in adjusting the correct amount of reflux. the temperature lets you judge the purity of the distillate output without having to measure it with an alcometer.09. or a detachable head that can be used without the whole column is desirable.gif&var2=0_0) ). They may be more difficult to locate than other packing materials. They do have the benefit of being more durable and last longer than many of the other materials. however.How To Build . Their low surface area and need for a container. The theory was that the temperature should be uniform in the column and temperature changes in the middle of the column could be noticed before the distillate being collected higher up changed.net/photoalbum/main. the temperature will allow you to know when your still has begun to reflux. Placement The original Boka design called for the thermometer to be placed in the packing. and be more expensive. While it is often shunned by potstillers. near the middle of the column.yahoo. This is commonly referred to as a de-tuned or un-packed Boka.[36] (http://dir. Removing packing for pot still mode If there is no packing in the column. and when to cut to tails. and the type of packing used. Marbles Glass marbles can be used as packing. Raschig rings Thermometer General theory A thermometer allows you to monitor the vapor temperature as you distill. if you are using mesh or scrubbers. At the beginning of the run. The type of support you will need will vary depending on the type of connection between your boiler and column. Temperature is the primary feedback in optimizing your distillation. there is nearly no surface area in the column upon which vapors can reflux.org/Boka_Reflux_Still_-_How_To_Build 10/18 .26. Containing packing Packing needs to stay in your column while the still is running. you will probably need to plan on including some type of screen or soldered supports to keep the packing material from falling out of the column and into the boiler.php? cmd=image&var1=pint_o_shine%2Falcoholvapor. makes them the least desirable of common packing materials. however. achieving a lower HETP and also requiring something inside the column to contain them. Later.artisan-distiller. as it relates directly to the purity of ethanol vapour at that point (see the ethanol / water phase diagram (http://www. this is likely to be unnessesary. If you are using something other than mesh or scrubbers. Again.Distillers Wiki Raschig rings Raschig rings are hollow cylinders made of unglazed ceramic material.2012 Boka Reflux Still . so insulation. in reflux distillation the thermometer becomes a invaluable tool to indicate when to begin collecting the distillate.homedistiller. They are pretty common and are very easy to clean. This allows a Boka to function as a pot still. Some condensation can form on the walls of the column. They are made in many sizes but the ¼" diameter is perfect for this kind of column.com/group/new_distillers/message/16745) Later designs call for the thermometer to be wiki. They are a less effective packing than mesh or scrubbers. Sensing fine changes in temperature is much more important than a highly accurate temperature reading. just below the upper slanted plate. or pure PTFE plumbers/thread tape. Placements further down the column can provide advance notice of changes occuring before they influence output.homedistiller. Materials Many methods can be used to get a thermometer reading from the column. the still is said to be in '100% reflux' or 'total reflux'. and then the thermometer can be sealed into this tube using cork. and by the time you taste them. Distillate that drops down into the packing during the reflux process can have a different temperature than the vapor and make it more difficult to properly identify the minute changes in vapor pressure that denote change in purity or composition of the vapor.php?f=2&t=434) [40] (http://homedistiller. shielding the thermometer from falling distillate.09. mainly generated wiki. are often more sensitive to minor changes in temperature. so it can be difficult to use a glass thermometer. you can use a compression fitting to keep the probe in place and seal the column.php? f=36&t=8804&start=2) Both locations have their merits. [39] (http://homedistiller. it's too late! Type Many reflux distillers will change valve settings or cut to tails based on a 0.Distillers Wiki placed above the top of the packing. A plain hole can be drilled into the side.26. feel that over-dependence on a thermometer can be a crutch that will prevent good cuts. as undesirable fractions like tails can be very hard to detect using taste and smell at high alcohol levels. a small tube serves as an outlet where the distillate can be drawn off. but the consensus would be that placement above the packing is most useful. a short section of 1/4" or 3/8" tube can be soldered into a hole in the column. [38] (http://homedistiller.php?f=17&t=15513) Need The temperature readings only give an idea of when vapor purity or content are changing and some distillers.org/forum/viewtopic.org/forum/viewtopic. A thermometer isn't 100% necessary to run a reflux still. If all of the distillate falls back into the column. but will make it much easier to run in an optimal fashion. Digital thermometers.homedistiller. Alternatively.2012 Boka Reflux Still . flour paste.php? f=1&t=1110) Pikluk's Boka head with thermo probe inserted Output Tube & Needle Valve General theory The lower slanted plate inside the column of the Boka collects distillate that has been condensed. At the lowest point of this pool. which has a hole into which the thermometer is inserted. [37] (http://www. This distillate forms a pool which will eventually overflow and fall back down into the column as reflux.How To Build . especially of pot stils. while sometimes inaccurate to several degrees. For heavier thermometers. but thermometers there are best seen as suplementary to the essential top thermometer.org/Boka_Reflux_Still_-_How_To_Build 11/18 . if you are using a digital thermometer with a metal probe. If this outlet is opened completely and no pool is able to form or fall back into the column. and plugged with a cork stopper.org/forum/viewtopic.org/forum/viewtopic.1C change. the still has a very small amount of reflux. or 'equilibriating'. and thermometers should be chosen according to these needs. as this is a safe material.org/forum/viewtopic.php?f=2&t=8717&start=0) Pipe size The most common size of output tube is 1/4" (6mm). and gives the best amount of control. rubber or PTFE (teflon).php?f=17&t=16770&start=0) .Distillers Wiki by condensation on the underside of the slant plates due to cold reflux falling on them and passive heat loss throughout the column (these two things are what prevent a Boka from being completely the same as a pot still when detuned).homedistiller. Read about pickling brass here: [42] (http://homedistiller. usually measured in a specific number of drops per minute of drawn-off or collected distillate.php? f=33&t=16707) Compression fitting needle valves are very popular. use a copper outlet tube. While others find that doing them simultaneously only encourages solder to leak out of the lower plate when the outlet tube is being heated for soldering. Try to ensure you get a needle valve with a PTFE seal. but will be lead-free and highly adjustable and accurate [41] (http://homedistiller. and can be one of the most expensive parts of the still. or if PTFE is unavailable. The larger size isn't necessary for flow. The rate of distillate removed from the column directly controls the amount of distillate that can pool and fall back into the column. ensuring that it is placed in the lowest possible position above the plate for maximum drainage. but the larger needle valve will give you better flow when fully open (for stripping or when using your Boka without reflux as a pot still) [44] (http://homedistiller. The templates in the 'slanted plate section' show the proper drill location if you can't properly locate it. Brass valves are far more common locally and much less expensive.php?f=2&t=8717) If you use brass. don't forget to pickle it to get rid of any lead that may be in or on it. This demands a very precise method for controlling the amount of distillate that is removed from the output tube. but some brass contains lead. If you have a copper column. Many of the brass fittings are of sub-standard manufacturing quality. as they will not require soldering. Others feel it is overkill and sticking with 1/4" (6mm) is cheaper and perfectly acceptable [45] (http://homedistiller. DIY valve wiki.php? f=2&t=13871) . Take caution if you solder your valve into place not to overheat it which may ruin the seals inside. and may be very inefficient at getting proper control (ie. A needle valve is the best choice. though you may choose a 3/8" (9mm) output tube. and should be pickled on a regular basis for safety. it may be hard to get exactly 3 drops per second if that were your desired output. (Some users find that it may be easier to solder the lower slanted plate and outlet tube at the same time since it requires the area to be heated only once. Many similar valves are less efficient and lack the amount of control needed to properly adjust a column for the best amount of reflux. A true needle valve has a needle inside that seats into a hole such that flow is minimized or stopped.How To Build . A good stainless steel needle valve may cost as much as 10-15 times as much as a brass equivalent and be harder to procure locally. Materials The output tube should be made of the same material as your column so that it can be soldered or sealed accordingly.org/Boka_Reflux_Still_-_How_To_Build 12/18 .org/forum/viewtopic. and are usually available in either brass or stainless steel.) Stainless steel needle valves tend to be much higher in quality.org/forum/viewtopic.org/forum/viewtopic.org/forum/viewtopic.09.) Needle valves are not available in copper. It is best to drill and solder this tube after soldering in the plates. Note that nearly every commercially available needle valve has some sort of seal or seat.[43] (http://homedistiller. and thus the reflux ratio.26. Some of the DIY options below are available without any seals and may be a better choice for distillers concerned about synthetics.2012 Boka Reflux Still . This seal may be made of plastic. Strong ethanol (especially HOT/BOILING and in vapor). This is typical of real-time measurements such as those provided by a parrot or parrots beak. is an wiki. Proper precaution.php?f=17&t=16593) . but results in drawn-off and collected distillate being very hot when collected. common sense. but only in the fermentation process). Materials safety Most plastics and sythetic materials are inappropriate for use in the distillation process (HDPE containers can be used.php?f=2&t=8870) is a very cheap and elegant DIY needle valve with no synthetic seals.org/forum/viewtopic. There is absolutely no need to seal the top of the still and doing so can cause incredibly dangerous build-up of pressure. This forum thread (http://homedistiller. and be full of flammable vapors. Never leave your still unattended and ensure that you have proper fire retardants nearby (ie. They are typically made of copper. Some Boka users choose to run a secondary external condenser on their output tube just after the needle valve [46] (http://homedistiller. there should not be any vapor leaving the still. [49] (http://homedistiller. and when used correctly. many users have no secondary condenser. is very safe.org/forum/viewtopic. The primary reason for having cool distillate is so that accurate proof/ABV readings can be made as the distillate exits the still.php?f=2&t=10196) includes some info on adjusting a common brass needle valve to be more finely adjustable. It is a device used to hold distillate and a proof hydrometer which allows distillate to flow out while giving a proof reading.org/forum/viewtopic.Distillers Wiki This (http://homedistiller. All stills used to distill spirits by their very nature will contain or be on a heat source. Make sure your Boka is open above the condenser or has a proper pressure release valve that cannot fail.2012 Boka Reflux Still . the pooled distillate is constantly being heated back up towards vaporization threshold again.org/forum/viewtopic.php?f=2&t=15341) (A parrot is not an animal.homedistiller. or use a cooled parrot[48] (http://homedistiller.org/forum/viewtopic.09.org/forum/viewtopic.org/forum/viewtopic.php?f=17&t=7626) . Vented top If your condenser is working correctly. or just use a long output tube that gives the distillate more time to air cool before being collected.php?f=17&t=18270) is a rough plan for another DIY needle valve that could be 100% copper and pretty cheap to make. so the hydrometer is always visible and measuring. Here (http://homedistiller.How To Build . Secondary condenser Because the lower slanted plate which holds the 'pool' of distillate sits directly in the vapor path. This makes for a more efficient reflux. and general disilling safety should be used at all times.php?f=32&t=13736) . Braz's liebig condenser on the output tube This being said. a fire extinguisher or ready water supply.org/Boka_Reflux_Still_-_How_To_Build 13/18 .26. Secondary condensers range from Liebig arms to a graham condenser that runs off the same coolant used for the main condensing coil inside the column [47] (http://homedistiller.) Improper use of a still can result in serious injury or death. Check your still for leaks at the beginning and during each run using a mirror or flashlight. and then the released flammable vapor would ignite and explode and kill you again.) Safety considerations A Boka is a very simple still to use. This high pressure can cause your still to explode which could kill you. Be aware of your local laws Building. Don't rely on what you think or have heard about what is legal. which is when foam and mash rise up the column and exit the still. and cleanup immediately if you do High proof distillate can be very flammable. More links to still safety Basic Distilling Safety (http://homedistiller. owning. this community STRONGLY recommends not using plastics. However. as can rags used to clean spills . This subject seems to always generate lots of heated discussion. don't use it. Don't rely on common sense or folk tales about what is allowed. Solder is cheap. Some mashes produce some serious foaming when boiled and can cause the still to puke.php?f=33) Cleaning and prep for use wiki. Also ensure that your collection container is large enough that it can collect any distillate that is collected if you aren't paying attention. Safety tips (http://homedistiller. Also.org/forum/viewtopic. Don't spill. and the flame can be nearly invisible in normal light or daylight. possessing. Safety and related issues subforum (http://homedistiller. which could make a mess or start a fire.org/forum/viewtopic. If you don't like your laws. Check you local and federal (where applicable) laws to ensure you are in compliance.php?t=5166) ). clean up the spill immediately and be smart about discarding rags used to clean up spilled distillate. Most materials are simply not safe to use. call your local legislator and get them changed. Some people do this.2012 Boka Reflux Still .09.26.How To Build . storage of high proof ethanol in plastic containers is not a good idea either.Distillers Wiki extremely strong solvent. of after the vapor has been condensed). Spilled distillate can catch on fire.php?f=41&t=9480&start=60) No lead solder Lead in solder can and probably will find its way into your still. You may choose to set your collection container inside a large pan that can collect any overflow in a worst case scenario. buying. But this community is VERY serious about keeping plastics out of the distillation process. Proper collection container Ensure that your collection containers are stable and don't tip over into or are near your heat source. Do not overfill your still boiler. The ONLY exception to this rule currently is PFTE/Teflon.a bucket of water handy to throw them in is a good idea. Storing. If you spill. An overflowing collection container can be really dangerous. or plastic tubing on the “take off†the still (i. Some places to be cautious (even if your still was commercially manufactured). running. and all parts of your still (Borrowed from a FAQ on the main site. selling or buying the distillate that comes out of your still will likely be even more illegal. or storing a still may be illegal where you live. using. If you aren't sure or if your solder isn't labeled. This can cause your collection container to overflow. selling. by Husker [50] (http://homedistiller.org/forum/viewtopic. and even a few lower commercial products are stored in plastic.org/forum/viewforum.php?f=33&t=4282) . which has been scientifically tested in a distilling application [51] (http://homedistiller.org/forum/viewtopic. watching.e. is using plastic tubing to join the copper tubing. and there are additional solvents in the heads fractions such as acetone. Check your local laws and don't break them.php?f=33&t=11187) . Only use solder that is clearly labeled as lead-free solder.org/Boka_Reflux_Still_-_How_To_Build 14/18 . and lead-poisoning is extremely serious.homedistiller. attach the still head. Vinegar Cleaning Run Next.the problem if you don't run steam through it is that some areas (like the top of a liebig condenser or coil) may be untouched in normal. Take time to scrub your materials with soap and water after purchasing them but before building to remove anything they came in contact with during shipping and storage. brazing. Doubly so if you are using recycled pipes or fittings. It is beneficial to run without cooling for a period. Keep the vinegar solution. This is a really good time to get a (glass!) mirror. wiki. If your column has packing. Continue to clean each piece off after soldering or assembly. taking extra caution to remove any excess flux. After steaming it for 20 minutes or so. etc.use dilute vinegar. the still requires cleaning to remove any contaminants that could negatively affect your distillate. If there are visual patches of flux and crap still in there. and check for vapour leaks in any seals and solder joins. turn on the condenser(s). or overnight. A reflux condenser may struggle to knock down all this vapour.org/forum/viewtopic. it's a lot easier to condense ethanol / water mix. it isn't necessary to have it in at this stage. condenser-on operation. Give everything a comprehensive rinse out with water. so this is a good time to double check that your still is always open at some point to the atmosphere. don't worry about that at this stage.How To Build . The following process should help prepare your still for proper use. Clean while building It is best to progressively clean it during the building process. pour the vinegar solution into your boiler. This multi-step process borders on over-kill. This is really an optional step. and bring it to a boil. Soak it for a good few hours. Many also choose to polish their materials before building which is far easier than trying to accommodate bits of soldered on metal that make later polishing harder. Check that the condenser(s) are knocking down vapour. but is a nice idea for things like coils. There is no fire danger .09. but only takes a little bit of extra time to ensure your still is perfectly clean. go back and do some more soaking and scrubbing before you continue. Shut down and dump your vinegar. The mirror will fog up if held up to a leak. Run with the condenser(s) on for 20 minutes or so. and it won't be very pleasant to breathe. The inside of pipes can be cleaned with a soapy scrubber pushed through the pipe with a broom repeatedly.2012 Boka Reflux Still . effectively giving the condenser an acidic steam .Distillers Wiki General Theory After building a Boka.php?f=46&t=15489) Soak and Scrub A really good way to start is to soak any parts small enough in a weak acid solution . Most of your still should be pretty shiny on the inside by now. Post-build cleaning runs This section taken from the Reading Lounge [52] (http://homedistiller.org/Boka_Reflux_Still_-_How_To_Build 15/18 . Of course. so many endorse it for peace of mind alone.but there is still vapour being generated. normal caution is needed with hot steam. and return your still to normal condensing operation. don't scald yourself.26.homedistiller. You can augment it by giving the insides a bit of a scrub as well with a kitchen scourer (don't use your packing for this). which you can reuse for the next step. org/Boka_Reflux_Still_-_How_To_Build 16/18 . If your still pukes (Mash boils over and rises up into the column). then the parts have been soaking too long and the copper in the brass is beginning to dissolve. Do not be alarmed at the patina that develops inside a copper column.org/forum/viewtopic. Some users go to the extra length of running the still with boiling water every so often to really clean things out. The solution has become contaminated and the part should be re-cleaned in a fresh solution. Simply rinse the still with water thoroughly just after using to keep things clean and fresh. The brass will turn a buttery yellow color as it is cleaned. and some users also run a vinegar and water solution or a citric acid solution every 5-20 runs to keep things as clean as possible. This second cleaning run can double as a practice of still operation. see how temperature and output respond to your actions. Pickling brass It has been mentioned elsewhere. and have a play around with heat / cooling / takeoff rate to get the hang of it.26. as the ethanol vapour is of course flammable. pretty much whatever you can make the cheapest and easiest. exposing more lead.09.you can use this for future builds. but others like them bright and shiny. you can use cheap box wine or something (avoid beer .How To Build . Don't treat this as drinkable. but do keep it. A solution of two parts white vinegar to one part hydrogen peroxide (common 3% solution) will remove tarnish and surface lead from brass parts when they are soaked for 5-10 minutes at room temperature. You can put the packing in for this. Use any old wash. and also heavy it sinks. The pickling process will prevent any lead that may be in the brass from contaminating the distilling process. pretty much any source of ethanol you like.php?f=46&t=13265) wiki. Do not repeat the steaming step we did with the vinegar run. Olddog has provided a good walkthrough to polishing a still. patina coated copper still. or take out your packing and clean out any particulates caught there. Copper packing will benefit from weak acidic cleaning on a reasonably regular basis (twice a year-ish)to remove built up sulfides and oxidation.org/forum/viewtopic. you should do an alcohol cleaning run as well.php? f=46&t=15489#p6848914) Regular cleaning It is a good idea to clean your still after each use. DO NOT use denatured alcohol for this (never put that through your still). If the solution starts to turn green and the brass darkens. Polishing Some distillers prefer a used. Alternatively. but part of your cleaning should be a regular pickling of any lead-containing brass parts that you have. Operation instructions Running your Boka as a reflux still: Husker's LM instructions (http://homedistiller. See how the ABV changes. clearly labeled as cleaning run alcohol .homedistiller. Usually this is just some joints and probably your take-off valve.it's hard to get the hop oils out afterwards). this is normal.Distillers Wiki Ethanol Cleaning Run To be completely thorough. Just run the wash in the normal fashion. [53] (http://homedistiller. Play around with the reflux management.2012 Boka Reflux Still . you might need to do more scrubbing with water. yielding low wines. triclamp flanges and clamps with a PTFE gasket can be used. Finally. but may contain lead and need proper pickling as regular maintenance. (The proper output is usually determined by your recipe. Some users choose to leave a small amount of packing in the column so they can run a wash in a single run. the reflux tends to clump and stream together instead of spreading efficently throughout the packing. Making this union out of threaded copper adapters can be extremely cost prohibitive. as triclamps and easy flanges are compatable with the flange on a uncut beer keg. defeating the purpose of a pot still. and remove too much of the flavor.php? f=36&t=8261&start=15) Alternatively. the lower the heat. you'll need to de-tune (remove the packing from) the column. 0-5C) there will be a significant amount of reflux. These could be spaced in the packing.php? f=46&t=15489#p6848914) . and seal the seams on the outside of the column using flour-paste upon assembly and before distillation.26. but should not be allowed to have the packing fill the aperture as it could cause the still to choke.org/forum/viewtopic. or to remove the packed section of the column and attach the head to the boiler for a stripping run or to use the still as a pot still for flavored spirits. Or.org/forum/viewtopic. Then you open your output valve completely and adjust the temperature on your boiler to give the proper output. Too much packing will purify the distillate too much. If you don't have a detachable head.Distillers Wiki Running your Boka as a pot still: If you have built your Boka with a detachable head. hot outside temperatures will drastically reduce the amount of reflux on the walls the Boka column.org/Boka_Reflux_Still_-_How_To_Build 17/18 . it is desirable to center the returning reflux halfway or two thirds of the way down the column. which are later run a second time at a lower temperature to give final output in a spirit run. just the right amount of packing and a slow boil and low careful output can yield a final product on the first run. This allows the head to be quickly removed for cleaning.org/forum/viewtopic. remove the packed column part of your still and run the still with the head attached directly to the boiler. Husker's instructions for running a detuned LM are here (http://homedistiller. as can triclamps in conjunction with an easy flange (http://homedistiller. Brass couplers are more affordable. [54] (http://homedistiller. you can use a common non-soldered slip-joint. A triclamp / easy flange connection here in combination with a beer keg boiler allows for very easy detune into a pseudo-pot still. but generally.php?f=2&t=9300) .How To Build . Reflux centering In taller columns (especially wide and tall columns).homedistiller.php?f=27&t=13752) [55] (http://homedistiller. A centering ring helps break up those streams and prevent reflux 'channels' from running down the column walls. to better access and remove the packing. Based on your mash ABV. Conversely.09. This is because as purity drops towards the bottom of the column. slower is better) There will be only a small amount of reflux like this. indoors) you may have to adjust the minimal packing in your Boka during the year to maintain consistency as outdoor temperatures fluctuate. (Note: air temperature outside the still can have a significant impact on the amount of reflux.org/forum/viewtopic. a pot still can be run hard and fast. The wiki. Optional extras Detachable head Some builders choose to add a threaded connection to the column just below the slanted plates.2012 Boka Reflux Still . With low reflux. 30-40F. the slower the output and the more distinct the cuts will be. If you are not in a controlled environment (ie. If it is really cold outside the still (ie. homedistiller.org/Boka_Reflux_Still_-_How_To_Build 18/18 . and less physically able distillers may find it easier to assemble the still in small parts.homedistiller.org/Boka_Reflux_Still_-_How_To_Build" Category: Equipment This page was last modified on 27 February 2011. Retrieved from "http://wiki. and use the joint to place the collar inside the column [56] (http://homedistiller.How To Build . wiki. This also means that the still column can be broken down into smaller parts for storage.26.Distillers Wiki easiest option is to have a joint (such as a triclamp union or a slip joint) in the column at the halfway point or 2/3rd down.09.org/forum/viewtopic.php? f=15&t=17849) . at 21:10.2012 Boka Reflux Still .
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