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meerkat

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  1. Bottle Filling Calibration

    ReadeHud, your math is correct. There are two reasons why the mass you have calculated for 750 ml is different from the values calculated by PeteB and Silk City earlier. The first reason is that the values calculated by Pete and Silk were for 750 ml at 60°F but you are working at 20°C. 20°C is a bit hotter than 60°F and the spirit expands and for the same volume you have less mass. The second reason is that although 80 Proof is equal to 40 Vol% at 60°F it is not the same as 40 Vol% at 20°C. Alcohol and water have different rates of thermal expansion and as the spirit is warmed from 60°F to 20°C the alcohol portion expands (very slightly) more than the water. This changes the volumetric ratio between the alcohol and the water. 80 Proof is equal to 40.07 ABV at 20°C, so when you buy equal volumes of spirit at 40 ABV from US and European suppliers you actually get a bit more alcohol from your US supplier. A large part of the confusion between weights and masses in air and in vacuum is our loose use of the terms weight and mass. We use the terms weight and mass interchangeably, but they are really two entirely different physical quantities. Weight is actually a force, and is related to mass by Newton's second law ( F = m x a ). The most common way to determine mass is to actually measure the weight (i.e. force of gravitational attraction to the earth measured on a balance or scale) and then infer the mass from the second law. Of course we don't actually do the math every time and the "a" term is built into the calibration of the scale and we simply read out the result as a mass in pounds or kilograms. The mass of an object is not affected by the presence of surrounding air, water or other fluid. Nor is it affected by the force of gravity. But weight is obviously affected by both. Using gravity to measure weight and inferring the mass is not the only way to measure mass. When astronauts spend extended periods in space it is very important for them to know how their mass is changing (for health reasons) but because they are weightless in space a normal scale will not work. They measure their "inertial mass", which is actually the same as the "gravitational mass". If all this is not sufficiently confusing, try using the Canadian alcohol tables which measure ABV using the "in vacuum" density value, and then use the "in air" density value to determine the volume of the spirit.
  2. Ethanol Water Contraction and Dilution

    PeteB - The calculation for the quantity of water required to dilute to a target proof is illustrated in the article I referenced before. The example is based on volumes, but it could easily be converted to weights using a similar method to what I showed above when using Tom's suggestion to use Table 4. whiskeytango - The questions you are asking are exactly those AlcoDens was designed to answer. The formulas are way too complex to use in manual calculations. They are freely available from the OIML site if you want to see just how involved they are. The AlcoDens calculator for doing this can convert back and forth between Mass (Weight) %, Density, Volume % (ABV), Proof and Molar % As an example assume there is an unknown quantity of 150 proof spirit to which we add 100 lbs of water. After mixing the proof is 100 proof. What was the unknown volume of 150 proof spirit and what volume of 100 proof spirit has been produced? In the example shown below Source 2 is the pure water (Proof = 0). I have set the Source 2 quantity to mass and given the weight as 100 lbs, but you could equally well give the quantity as volume. In the bottom right panel you tell the program that the quantity of Source 2 is the known quantity. Set the Source 1 and Final Blend quantities to Volume and it will calculate how much 150 proof spirit was used and how much 100 proof has been produced. THis could be solved using Tom's Table 4 method provided all quantities are in weight terms by starting off with the classic "Let X be the mass of 150 proof spirit" and noting that the number of proof gallons does not change when you add pure water. Once the answers have been calculated in weight terms they can easily be converted to volumes.
  3. Ethanol Water Contraction and Dilution

    Thanks Tom, using Table 4 is a bit easier because it provides data for every 0.1 proof and it is probably easier to understand. For comparison with my earlier calculation here is the Table 4 method. 160 pf spirit has 0.13903 WG/lb. Table 4 only starts at 1 proof and from standard engineering tables the specific volume of water at 60 degrees F is 0.12008 WG/lb. The weight of the spirit is therefore 100/0.13903 = 719.27 lbs and the weight of the water is 100/0.12008 = 832.78 lbs The total weight is 719.27+832.78 = 1552.05 lbs. This contains the same 160 PGs that were in the original spirit so we have 160/1552.05 = 0.10309 PG/lb Table 4 shows (without interpolation) that this is 81.6 proof and the specific volume is 0.12633 WG/lb Total volume is 1552.05 x 0.12633 = 196.07 gallons This is definitely shorter and more direct than my earlier calculation. But AlcoDens still wins, especially if the temperature is not 60 F and the calculated PG/lb requires interpolation.
  4. Ethanol Water Contraction and Dilution

    Disclaimer: I am the author of the AlcoDens blending app mentioned below, so I am probably biased. This question of how to do blending calculations comes up fairly often, so I wrote this article to compare 3 of the methods. I have not seen any really comprehensive guide to performing calculations using the TTB Tables, but I am aware of two distillers who are in the process of preparing books that will cover this. Hopefully early next year (2018) things will be better. The theoretical blend proposed by whiskeytango is unfortunately not in the form for which the TTB Tables were structured. The tables are designed to easily answer the question of how much water to add to dilute the 100 gallons of 160 proof down to 80 proof. But it can be done. I will show my solution but perhaps someone who actually uses the TTB tables can show an easier way. From Table 6, 160 proof spirit contains 80 parts of alcohol and 22.87 parts of water. BTW, the fact that these add up to 102.87 shows how the tables do include the effect of contraction. If we now add 100 gallons of water to 100 gallons of 160 proof spirit we still have 80 parts (gallons) of alcohol but we now have 122.87 parts of water. The ratio of parts of alcohol to parts of water is 80/122.87 = 0.6511. Now we have to scan through Table 6 to find what proof corresponds to this ratio. As I said, the tables are not structured to make this easy. At 81 proof the ratio is 40.5/62.95 = 0.6434 At 82 proof the ratio is 41.0/62.47 = 0.6563 By interpolation we see that a ratio of 0.6511 corresponds to a strength of 81.6 proof. This diluted spirit obviously contains 81.6/2 = 40.8 parts of alcohol. This came from the original 80 gallons of alcohol in the 160 proof spirit. If 80 gallons is 40.8 parts then the total parts (i.e. 100) must be 80x(100/40.8)= 196.08 gallons. Naturally, I checked this with AlcoDens to make sure I had the correct answers. Because I do not do these calculations using the TTB Tables very often I did make a few mistakes along the way, but the values above compare well with the AlcoDens answer shown below.
  5. Proofing using Gauging Manual Table 6

    Yes, the interpolation in Table 6 is very similar to that for Table 1. In fact it is a bit easier because you only have two parameters to deal with (proof vs parts of water) while in Table 1 you have three parameters (apparent proof, true proof and temperature). I have not seen the TTB data in the form of an equation - only as the Tables. There must be an equation because the Tables could not have been generated from experiments at every published point, and must have been generated from an equation. I just have not seen it. The data that is openly available as a formula is the European OIML alcohol-water density data. This is the data that forms the basis of my AlcoDens program. The OIML and TTB data are based on much of the same original experimental data but they are presented in different terms. The TTB data is (mostly) presented as densities and masses measured in air but the OIML data is presented as absolute or "in vacuum" values. Fortunately it is possible to convert between "in air" and "in vacuum" data so it is possible to select in AlcoDens whether you want to match the TTB or OIML tables.
  6. Proofing

    Distillers have been gauging their products successfully with hydrometers for over a 100 years and you shouldn't stress over that process. The TTB have posted some excellent videos that show and describe the process in detail. See https://www.ttb.gov/spirits/proofing.shtml If you know that you have dissolved solids in your product then the first step is to measure them using the petri dish and scale method you mentioned. If the total dissolved solids (TDS) content is less than 400 mg per 100 ml (or 4 gram per litre) then you are allowed to ignore the effect of the solids and use the standard TTB Tables. If the TDS is between 400 and 600 mg per 100 ml (4 to 6 gram per litre) then you must use the TTB formula to adjust the apparent proof to get the true proof. This is also described in a TTB video at the page I linked to above. This formula applies to a fairly narrow range of proofs - 80 to 100 proof from memory but subject to correction. If the TDS is above 6 gram per litre then you must use the lab scale distillation procedure also shown in one of the TTB videos linked above to get to the true proof. There are several useful discussions on this subject in previous threads and using "obscuration" or "lab distillation" in the search box at the top of the page will find them for you. Once you know what your proof is, adjusting it to your target proof is a whole different kettle of fish. As RobertS said above "be ready to repeat this a few times as you come down to bottling proof". The more accurately you can measure the true proof and perform your proofing calculations the fewer times you will have to repeat the process. Joe Dehner offered a manual procedure for these calculations in the thread You can see the computer program that I finally developed as a result of all these discussions at http://www.katmarsoftware.com/alcodenslq.htm and download a trial version if you want to test it.
  7. Running a seamless glass lab still

    See Part 3 of the TTB video series https://www.ttb.gov/spirits/proofing.shtml
  8. Hello from South Australia

    The Australian Distillers Association group on Facebook seems to be where most of the professional Aussie distillers hang out. There is also the Aussiedistiller forum at http://aussiedistiller.com.au which is very active but seems to be mainly home distillers. And of course there are some very active and knowledgeable Australian distillers right here in the ADI forum.
  9. Still design

    One part of your question which I did not address is whether it is detrimental to have a column that has a larger diameter than necessary. Unfortunately columns that are larger in diameter than necessary do not work as well as correctly designed columns. Depending on the type of column, there will be a narrower or wider range of flows over which it works well. With packed columns if they are too large the liquid will not wet all the packing and there will be zones where the vapor can rise up through the packing without contacting the liquid at all. WIth sieve (perforated plate) columns a minimum vapor velocity is required to prevent the liquid from weeping through the holes. A small amount of weeping does not affect the efficiency, but too much will cause the plates to run dry and in larger columns can lead to mechanical problems like vibration. Correctly designed bubble cap trays will not weep and these columns have the widest range of capacity. But even these trays will fall off in efficiency if they are grossly oversized because the intensity of the bubbling will decrease. This reduces the mixing and the vapor-liquid contact - reducing the separating efficiency of the column. Of course, for all types of columns a detrimental impact of over sizing is the cost of the column. The quantity of liquid held up on each tray also gets to be significant with very large columns and this can affect the recovery of alcohol in batch systems, but is not really a problem for continuous columns.
  10. Still design

    This subject was discussed in Unfortunately that thread got a bit messy with some irrelevant side-issues causing a bit of bickering and hair-splitting. Basically the situation is that the diameter of the column and the size of the pot are determined by different factors, so there is no fixed ratio between them. The column diameter is mainly determined by the vapor velocity up the column. In a small R&D column of around 2" diameter the vapor velocity will be in the region of 6 to 10 inches per second, but on a large vodka column of say 10 ft diameter you can get vapor velocities of 6 to 10 feet per second. So the column diameter is determined by the rate at which you want to run. In a pot still the pot size is determined by the heating method and the size of the batch you are working with. Let us imagine your fermenters produce 100 gallons per batch. You will probably want a pot of around 150 gallons to be able to boil this safely. If you want to process this in 12 hours you will need a column roughly double the diameter (4 x the area) than if you want to process it in 48 hours. And of course you need to put heat into the pot at 4x the rate for the 12 hour scenario. Distillers generally want to be able to process a batch in 8 to 12 hours (one shift) so it turns out that in practice there is an approximately consistent ratio between the pot size and the column diameter (or more correctly the column cross sectional area) but this is a coincidence - as explained above there are different drivers in determining the pot and column sizes.
  11. Volume issues in bottling runs

    Your 1674.8 lbs of 80 proof will give you 804.1 liters at 73.54°F. AlcoDens and the TTB Tables agree on this. But because 750 ml at 60°F grows to 754 ml at 73.54°F you should expect to get 804.1/0.754 = 1066 bottles. This agrees with PeteB’s mass based calculation. The underfill is 4 ml per bottle so you could expect to have 1066 x 4 / 750 = 5.7 extra bottles. The fact that you had 14 too many means that we still need to find where the extra 8 bottles came from. I agree that your scale is unlikely to be the source of error, but keep it in mind to check once you have eliminated all other possible reasons. If your proofing was out and the 1674.8 lbs actually gave you 810.0 liters ( = 1080 x 0.750) instead of the calculated 804.1 then your density at 73.54°F was 7.8262 lb/WG and this would correspond to a proof of 88.2. It is unlikely that you could be this far out. Another possibility for error would be if your bottling temperature was not the 73.54°F in your storage tank. But the temperature would need to be in the region of 90°F to explain the difference. This should be easy to check. As PeteB has said, it would be better to do your quantity checks during the run based on mass rather than volume. If you have an accurate lab scale you could also use it to calibrate your measuring cylinder. Use AlcoDens to calculate the expected weight of 0 proof (i.e. water) when your cylinder is full, and fill it with RO or well filtered water. If you have a bottling machine that uses a fixed head (pressure) and adjustable timer to control the fill quantity then you can set it to give a target weight rather than volume. The weight filled will vary with the temperature of the spirit and if you make a note of the time required and the temperature each time you adjust it you will soon be able to draw up a calibration curve to speed up the job.
  12. Adjusting Proof in Liqueurs

    No, the original AlcoDens is still available for those who only work with alcohol/water mixtures and do not need the capability of calculating liqueurs. The new product is AlcoDens LQ and it will do everything that the regular AlcoDens does, plus a few calculators that deal with mixtures containing alcohol, water plus sugar.
  13. Adjusting Proof in Liqueurs

    Thanks for the kudos PeteB. It is a complicated calculator to set up the first few times, and if anyone else is having similar problems they are welcome to send me some numbers and I will set up the calculation for them with an explanation of how/why I made the selections. Other users have also reported that after a few runs it becomes much easier, but the learning curve is a bit steep.
  14. How To Proof Rum With Brown sugar Added

    The lab still will allow you to determine the proof and sugar loading of your spirit, but if they are not on target then you still need the math to determine what to add to get to the correct levels.
  15. How To Proof Rum With Brown sugar Added

    If you know the proof and weight (or volume) of the rum and the target sugar loading then you can calculate the quantities of sugar and dilution water required to achieve 80 proof using the calculator downloadable from www.katmarsoftware.com/alcodenslq.htm But the final proof must be verified as described by bluefish_dist
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