StillDragon® Community Forum


Be part of our community & join our international next generation forum now!

In this Discussion

Double Distilling with a Baby Dragon

If I cut my first spirit run to 40% and then distil again. Is this the right abv to run with ? Thanking you


  • what are you trying to make? what are you heating with?

  • G'day new to his game but trying to double distill it to get a better tasting spirit.Have got a 55 liter keg with two 2200 watt elements,one variable.Was going to double distill 32 litres of spirit at 40%.Is this the right percentage or should I go lower.Thankyou for your interest and help

  • you can get fine tasting with one run, being extra selective on the hearts, then adding all the feints to the next run and getting a larger cut of hearts on all runs with feints added... when in doubt, take a smaller hearts cut and recycle the rest as feints... when in doubt, cut tails off and discard(especially on a plated column)....

  • To get the very best out of your boiler the theory of hydroseperation says your charge should be somewhere around 27-28%.

    Theory says that it makes the splitting of the water/ethanol bond better.

    StillDragon Australia & New Zealand - Your StillDragon® Distributor for Australia & New Zealand

  • Is that for any size boiler or specific to 55L?

  • Science of distillation does not depend on boiler size.

    StillDragon Australia & New Zealand - Your StillDragon® Distributor for Australia & New Zealand

  • edited March 2017

    Diluting The Still Charge - By Harry Jackson

    Economy in distilling is something all stillmen should consider. Given that between 75% and 90% of the cost of producing a quality product is spent directly on energy requirements, anything that can reduce this energy consumption is certainly worth more than a cursory glance.
    One such item is the amount of energy used to separate the ethanol from the water. This can be reduced considerably by lowering the initial strength of the still-charge. How is this possible?
    It has to do with the molecular attraction between ethanol and water. This attraction is called Hydrogen bonding. At the tiny atomic level, molecules of any substance have a stronger affinity for like molecules than for unlike molecules. This is why we can have pure substances such as water or ethanol, because the molecular attraction for molecules that are the same, is much stronger than the attraction for different molecules.

    How does this affect the energy input used in distilling? Simply by using only enough energy (heat) to break the weaker water/ethanol bonds, leaving the other stronger bonds relatively intact. It follows from this, that the fewer water/ethanol bonds there are to break, the less energy will be consumed.

    What has this to do with diluting the still-charge? Quite simply, the easiest way to ensure fewer water/ethanol bonds is to dilute the still-charge with more water. Let’s look further at this hydrogen bonding situation. It needs to be understood thoroughly to grasp its relationship to the initial question of still-charge dilution.
    Let's call ethanol bonds A-A, water bonds W-W, and ethanol/water bonds A-W. The A-A bonds and the W-W bonds are strong, while the A-W bonds are weak by comparison. In any given solution, there will be lots of A-A, W-W and A-W bonds, but the more ethanol you have in the solution, the more A-W bonds you will get, due to the difference in molecule size, the number of available attachment sites and the affinity between water and ethanol.

    All we want to do in distilling is break the A-W bonds, leaving the others relatively intact. In other words, separate the water from the ethanol. This requires energy input. If you have a solution low in alcohol, then there are less A-W bonds to form and break than either of the other two, which we don't want to break anyhow. Therefore less energy is required to separate just these A-W bonds than if we were separating all the other types of bonds as well. Less energy input to achieve seperation.

    StillDragon Australia & New Zealand - Your StillDragon® Distributor for Australia & New Zealand

  • Thankyou for the advice. First run is ok but was trying to improve it by distilling again. Sounds like get it right the first time.So more water in the wash and less alcohol ?

  • There's at least 50 ways to still your spirit. Depending on the product you could have a play with as many as you like and see what suits your palette and habits best.

    StillDragon Australia & New Zealand - Your StillDragon® Distributor for Australia & New Zealand

  • Yep experiment Thanks

  • Hmmm. I believe and work with Harry's reasoning on the starting concentration for a spirit run, but I'm not sure I buy that quoted statement about van der Waals forces changing the actual heat of vaporization of either water or ethanol.

    Zymurgy Bob, a simple potstiller

    my book, Making Fine Spirits

  • Thanks for the clarity punkin it helps me a lot

  • @zymurgybob said: but I'm not sure I buy that quoted statement about van der Waals forces changing the actual heat of vaporization of either water or ethanol.

    My money is on this guy...

  • Hi Folks

    Reading this post with some interest as I'm looking to a) get greater efficiency from the still and b) ensure when driving off tails, there's water covering the heating elements (specifically on the 200l still dragon boiler that needs 65 litres to cover them)!! Right now I'm running a test on a 50l milk can still where the charge for gin production has been reduced from 50% abv to 40%abv - I've dropped the botanical loading proportionally but retained the same still configuration and heating process (for heating and spirit run). What I have discovered is that the time from power on to spirit take off was shorter and that the abv of spirit was much less. Usually first portions of the hearts are coming off at around 83.5% upwards, in this case it was 82.0%. I'm guessing that an increased volume of water is going to absorb more energy to bring it up to temperature. Is this impacting on the energy absorbed by the alcohol. If so would I be correct in assuming that energy transformed from the body of water is preventing a more gradual heating of the alcohol (transferring to vapour) and therefore more reducing reflux time prior to take off. Only mention this as the temperature guage in the top of the still stayed low until just before take off, then rocketed.

    Now, would a torpedo or taller riser (pot still set up - no plates) help out here? Or is this just a case of slower heat up times?

    Thanks in advance

  • edited April 2017

    the etoh / water ratio and how it affects boiling point is simply explained by looking at this graph


    a 10% wash will boil at 199.5f and produce vapour initially at 54%.

    a 24% low wine will boil at around 10degrees f lower due to the increased alcohol

    The process of hydro-separation is well known and has been discussed here before. diluting your spirit run to 20 - 25% will give you a better cut.

    adding a torpedo or taller riser won't help it will just take longer to heat up as you suspect.

    995 x 691 - 38K
  • edited April 2017

    I came across quite a nice little Excel calculator that takes altitude into account as well as start and end abv. Quite nice for us when we sit at 1,800 m above sea level.

  • Not quite sure what's going on spirited. One thing that may help you is to keep your boiler charge on a redistillation to 27%ABV or less. It is easier to break the water/ethanol bonds (takes less energy) and the increased dilution helps the process eliminate contaminants. It will take more time to heat up a larger boiler charge of course.

Sign In or Register to comment.