02 January 2017
As I write this our still, Valeriya, is cranking out the first purification run of the first production batch of vodka from our distillery. That batch, like every batch that will follow, is made from grain by hand in Fairbanks, Alaska.
Our production batches are 350 gallons of vodka. Each production batch is made from four big fermenters (550 gallons each). We start one fermenter per day for four days in a row.
Each fermenter begins by heating water, then transferring it to the mashing tank. Veronika has a large mixer built in as well as a cooling jacket. While heating water, we grind up hundreds of pounds of grain, which is dumped into the near-boiling water and cooked for about an hour in the presence of an enzyme that cuts up starch (long chains of sugars) and lowers the viscosity. We also adjust the pH when necessary because the enzymes and the yeast prefer a slightly acidic environment.
After the grain is cooked, we cool the mash a little bit and add two more enzymes, whose job it is to reduce the starch to single sugars. Yeast can’t eat complex sugar chains like starch, so this is crucial. Once the starch is entirely converted to simple sugar (30-40 minutes) we cool it again to the optimal temperature for the yeast. Yeast likes it warm, but not hot, so when the temperature gets there we pour in a bunch of yeast that we had been hydrating earlier. We mix it in and then pump it into a fermenter, doing quite a bit of splashing to make sure to entrain as much air as possible.
The yeast goes like mad for about three days. At first, with oxygen, it grows and divides very quickly. Then it runs out of oxygen and starts making alcohol. Yeast only makes alcohol if it is starved for air, soiIf we handle the yeast right we will have tons of very lively yeast cells when they run out and then alcohol conversion takes place like a tempest. In three days it is nearly done, but we let each fermenter go for four days just to be sure.
The fermenter are, each in turn, pumped into the still and all the alcohol (and a bunch of contamination) is stripped out into a production tank. The still can take half a fermenter at a time, and it is run without any kind of purification column so that anything that boils in the kettle is collected in the production tank. This raw liquor comes out at about 130 proof and is full of nasty smelling contaminants. All four fermenters (eight cycles) are stripped into one production tank, ideally creating at least 280 proof gallons of alcohol.
[A note about alcohol units- in production a distillery measures inventory in proof gallons, a unit that equals the number of gallons multiplied by the proof and divided by 100. E.g. 200 gallons of raw liquor that measures 120 proof equals 240 proof gallons. Alcohol concentration is often also measured in % by volume and in proof. The proof is always twice the % by volume, so 40% alc by vol means 80 proof and vice versa.]
There is always some waste in every step of the vodka making process, so we prefer to start off with over the 280 proof gallons.
Once a production tank has the desired number of proof gallons, we clean the kettle and reconfigure the still so that the vapor path rises up through a vertical purification column to a pre-condenser (also known as a dephlegmator) then to a final condenser and then into a newly cleaned production tank or other collection vessel. We put the batch into the kettle and heat it so that vapors are driven to the top of the column. The pre-condenser there cools the vapors and they rain back down the column and back into the tank. We allow the vapors to reflux for at least an hour, which allows a temperature grandient to build up and stabilize in the column. The hottest at the bottom and coolest at the top. This allows the lowest boiling point (bp) chemicals, which are unwanted and toxic contaminants, to accumulate near the top of the column.
Once we have a stable temperature gradient, we reduce the cooling power to the pre-condenser and allow some of the vapors to escape. It’s an art: too little cooling at the pre-condenser and you are no longer purifying, too much and it takes 99 years to process a batch. These escaped vapors are cooled more by the condenser and run down through a pipe as a liquid.
The first liquids collected this way are called “Feints” highly contaminated with methanol (poison) and other things. We collect these separately. They can not be sold for drinking. The next ‘fraction’ is called the “Heads”. It isn’t as toxic, but it isn’t the stuff of good vodka. Once the heads contamination passes, the good stuff comes out. This fraction is traditionally known as “Hearts”, and it will become our vodka. Later on, as the temperature increases a bit, heavier chemicals start to come out in the product. The final fraction is named “Tails”, and it tastes badly, but tails fractions from multiple batches can be combined and re-distilled later.
The Hearts are diluted with water to 50% alcohol or less and redistilled as many times as it takes to taste good. Each time Feints, Heads, and Tails are removed and the quality of the Hearts improves.
Once we are content with the Hearts of a batch, we dilute it to between 40% and 50% alcohol. Then we treat it by slowly passing it through an column packed with activated carbon. This removes further impurities and improves the quality. We repeat this a number of times to attain our target quality. Next we chill the batch to below freezing and pass it through microfiber filters as a final clean up.
We buy our bottles plain and apply our own labels. Then we clean and fill each bottle, insert the stopper and seal them so that they are ready for sale.
-Toivo Luick, owner