Hydroseparation means something like this: to separate fractions by adding water. Can water actually do that? Separate fractions? Yes, it can! Here’s how it works, where it came from, and how you can apply this technique yourself.
Hydroseparation: how it works
Simple. Dilute the Heads and Tails you collected during your spirit run to 17%, by adding water. At 17%, the alcohol/water mix lost so much of it’s solvent characteristics that both Heads and Tails come out of solution. Heads will sink to the bottom, while Tails start to float and form an oily film on top.
Hydroseparation: where it came from
The Scottish and the Dutch use hydroseparation of old. The Scots while making whisky, the Dutch for their old style korenwijn and genever. Both the Scottish and the Dutch are known for being stingy. Hydroseparation helps them to recover every drop of ethanol from their Heads and Tails cuts. Both whisky and genever are known to have lots and lots of taste. Hydroseparation is a technique they use to up the total taste levels in their drink.
Hydroseparation: how you can use it
Dilute your Heads and Tails cuts (often collected together in the so-called Feints container) to 17%. Syphon off the middle 2/3rd. This faction consists of very tasty ethanol, almost devoid of Heads and Tails. Add this middle 2/3rd to the next run. This way you recover both the ethanol and you get to harvest a lot of additional taste.
Since this is about taste and about recovering ethanol, that was originally mixed in with your Heads and Tails cuts, hydroseparation has a role in potdistilling. When you make vodka or neutral, and use the Pure Program, the Heads and Tails factions will be so much compacted, that the ethanol recovery potential is nill. In short: when doing runs in Pure Mode … don’t hydroseparate the Heads and Tails cuts. When doing potstill runs … please do.
Let’s say you use the iStill One to make a whiskey. Since you have been following this Blog, and/or because you had the proper training that comes with the purchase of the iStill One, you know you don’t need to distill twice. The iStill One will give you a perfect Heart cut at barrel ageing strength in one go.
So let’s make that first run. You fill the boiler with 1000 liters of an 8% grain wash. You fire her up at maximum power, probably setting the agitator at like 8 or 9 revolutions per minute, since you distill on the grain.
When the temperature reaches 78.3C, whatever you collected is considered Fores. Toss them and adjust power to 55%. The next 2 to 3 liters you will probably collect as Heads. Put them in the Feints container. Now the actual Hearts run starts. Collect this as product. When it starts? Probably around 70 to 72%. When to end? Depends on the wash and your goals … but let’s say 50%. You now have a Hearts cut of around 60%. Congrats! No need to water down that tasty whiskey prior to barreling.
Under 50% you probably switch to Tails collection. Do so until you reach around 30%. Then stop the run. Oh, and collect the Tails in the same Feints container. They join the Heads, so to say.
Now comes the fun part. Dilute the contents of your Feints container to 17%, so hydroseparation takes place. Syphon off the middle 2/3rd and add this to the next whiskey batch you will run.
You will now have recovered allmost all the ethanol from Heads and (especially) Tails. You have upped the ABV for the second run to around 9 to 9.5%. And you have added lots of fruity and nutty tastes in the process. Your next Hearts cut will come over at around 62 to 63%. And you know what? This Hearts cut is going to be bigger, because you added the recovered ethanol!
What you do with the remaining 1/3rd in the Feints container? Keep it. Collect the next batch of Heads and Tails and add them to the Feints container again. Because there are now twice as much Heads and Tails, they will separate even better, when diluted to 17%. You will see that oilsy film develop on top of the Feints container. And if you have a glass Feints receiver, you will see the Heads fog up the lowest parts …
And there’s more!
Big distilleries like Jim Beam, Jack Daniel’s, and Buffalo Trace use hydroseparation in an all together different way. More on that … in another post!