Pot distillation
With column distillation the goal is to produce as pure alcohol as possible from pure sugar. Pot distillation is the opposite and one ferments mash with water, sugar and fruit. The goal is to get the genuine taste from the fruit in a fruit wine with maximum alcohol content, and this will then be distilled in a pot (alembic) still without column so the fruit taste follows the alcohol.
There is a good book about pot distillation at http://www.schnaps.co.at (in German).
Pot Distillers yeast
We have developed a pot distiller’s yeast to achieve more alcohol; better taste and higher quality in pot distilled spirits. We have ended up with Pot Distillers yeast, which ferments faster, produce more alcohol, less volatiles and get more fruit taste from the mash. To achieve this one must ferment with higher pH in the liquid and keep control of the liquid temperature.
Yeast strain
The strain we use in the Pot Distillers yeast is a genuine clean (bacteria free) wine yeast which is used widely for fruit brandies. Furthermore, the strain is grown under sterile conditions to ensure absence of bacteria which could otherwise influence quality of alcohol produced and the % yield from sugar. Much other yeast is a by-product (deposit) from molasses fermentation – and therefore not bacteria free.
Never ever use our instructions on other brands of yeast. If the other brand of yeast is not bacteria free (grown under sterile conditions, cost more) you will end up with a serious bacterial contamination. With other brands of yeast’s you must lower the pH to be safe.
pH in the fermentation
It is normal to have a pH of 3 in fruit mash fermentation’s, usually reached by adding citric acid. At this low pH the yeast can ferment (slowly) but bacteria’s can not survive.
Pot Distillers yeast works best in a pH between 3.8 and 5 and very best between pH 4.5 and 5. This is possible only because this yeast is bacteria free and starts fast and produce a lot of alcohol the first 48 hours, which kills the bacteria’s anyway.
To achieve this pH one adds 1/4 teaspoon of chalk per kilo fruit used. With this one achieve 18% alcohol, which extracts more flavor from the fruit and gives a much better yield and faster fermentation. If you prefer to have pH 3, alcohol will reach 14% only and the fermentation will be much slower with a risk for it to stop to early.
Alcohol strength in fermentation
In old traditional recipes 6% alcohol was often the yield from fruit. With Pot Distillers yeast this is quite different. By adding sugar one can get 18% of alcohol. This alcohol and the carbon dioxide produced during fermentation, also extracts more flavors from the fruit.
When adding sugar one uses 17 grams of sugar to produce 1% alcohol in 1 liter mash and have to remember to calculate space for the water. With 18% mash one sometimes get a better product in one distillation then with 2 distillations with the same mash at 6%.
Liquid temperature influences quality and alcohol strength
Pot Distillers yeast is selected to produce as less volatiles as possible. In alembic distillation some volatiles (like fusel oils) always follows the spirit. Pot distiller’s yeast reduces the amount of volatiles. The amount of volatiles can be even more reduced by controlling the temperature of the fermenting mash.
Difference of taste quality scored out of 10 is:
At 20°C air temperature 9,
At 25°C air temperature score 8,
At 30°C air temperature score 6,
At 35°C air temperature score 4.
As the fermentation produces heat this means the liquid temperature must not go over 30°C to score 8. To score 9 the liquid temperature shall not increase 24°C. To score 10 the liquid temperature shall be 20°C, but this will take very long time to ferment. If the liquid temperature increases 30°C, the mash can not reach 18% alcohol.
Do not ferment more the 25 liters in the same batch, the heat will increase too much. The heat must in this case be controlled by cooling or by slowing down the fermentation. Slowing down the fermentation is often possible by adding 1/3 of the sugar in the start and 2/3 after 1 week. Another way, worth a try, is to use half dosage (50%) of the yeast – but not less, then fermentation will stuck. This will increase the fermentation time from 7-10 days to 3-4 weeks.
Carbon dioxide produced during fermentation is a great solvent for flavors. Carbon dioxide helps the alcohol to extract the flavor from the fruit. When carbon dioxide leaves the fermentation it also contains some flavor.
When the liquid temperature is over 30°C, the amount of flavor leaving the mash increases very much. So try to not let the liquid temperature go over 30°C to keep the flavor in the mash.
Taste and distillation
To get maximum taste from the fruit one add pectolytic enzymes to the fruit in the start of the fermentation. Pectolytic enzymes is destroyed in temperatures over 55°C and works best at 40°C - 50°C.
Pectolytic enzymes breaks down pectin and cellulose in the fruit so the fruit taste (flavor) can come free. In Grappa distillation it is often a good idea to add enzymes to the press rests, even if enzymes already have been used when the grapes was pressed. One use to get more taste from the mash.
If one distills a cloudy mash it taste bad. It is that simple. To make a god fruit schnapps there is 2 ways to go:
1. Distill with the boiling vessel heated by hot water in a water bath. This is how most distilleries do, using a jacketed tank to heat the mash. Then they can distill very thick pulpy fruit mash and get a great taste anyway.
Or:
2. Clear the mash so it is crystal clear. Then it can be heated with any heat source without producing bad taste. The easiest way to do this is to do pulp fermentation for 3 - 4 days, then sieve through a straining bag and then complete the fermentation using a bucket.
What is this? It has never been done this way before
Why change the way it has always been done?
Our goal have been to produce a Pot Distillers yeast that achieves 18% alcohol, make less volatiles and extracts more taste from the fruit. To make a great yeast for pot distilling. To make this possible we have had to make those changes in pH and add more sugar. Try it and you will love it.
Please never, ever follow those instructions with another brand of yeast. There is a large chance that it will not work, as it must be a fast starting, high alcohol producing, totally bacteria free yeast with special nutrients for pot distillation.
Pot Distillers Instructions
1. Add your fruit into a 25-liter clean plastic bucket. Always wash
The fruit before use in warm water. If you have a recipe, follow it.
Soft Berries: Should be crushed - use between 5 – 8 kg / 25 liter.
Hard Fruits (Apples / Pears etc): Should be thinly sliced, the cores
removed and any bad parts cut out. Use between 8 – 10 kg / 25 liter.
Dried fruits: Large pieces should be sliced thinly, then soak all for 2
hours in lukewarm water. Use between 2 – 4 kg / 25 liter. Remove fruit debris before instruction 1 (stalks, leaves etc). Fruit stones should not be crushed - they can lead to unpleasant flavors in the distillate and also some harmful by-products. This work should be completed as quickly as possible. It is possible to ferment the fruit inside a straining bag to save work later.
2. Add 5 liters boiling water, stir bucket contents. Now add 3-kg sugar
and stir for 2-3 minutes then leave to cool to 50°C. Once the liquid
temperature has dropped to 50°C, add Pectolytic Enzyme and stir well.
Now leave for 1 hour.
3. After 1 hour, top up to 20 liters with cold water, stir well for 2-3
minutes - do not proceed until the liquid temperature has dropped below
30°C. The pH should be adjusted to between 4.5 - 5.o if you are able to
adjust it, if not, then add 1/4 teaspoon chalk per kg fruit used. Now add
the Pot Distillers yeast sachet contents and stir well. Do not add any acid.
4. Leave to ferment for 2-3 days with a lid placed loosely on the
bucket. After 2-3 days, remove the fruit using a straining bag - but
ensure you squeeze the straining bag tightly to release all fruit juice
back into the fermenter.
5. Separately dissolve another 3-kg sugar into 4 liters hot water. Once
dissolved, wait until the temperature drops below 30°C before adding
into the fermenter. Top up to 25-liter mark with cold water.
6. Now replace bucket lid and leave to ferment for 7 - 10 days at as
near to 20°C air temperature as possible until fermentation stops.
A constant / even fermentation temperature of between 20 - 25°C is
excellent. Fermentation will go very slow or even stop below 15°C.
Above 30°C fermentation will be too fast and the quality of distillate
poor.
7. After fermentation, siphon liquid from heavy sediment. Discard heavy
sediment and add clearing agent to liquid and leave for 2-3 days.
Siphon liquid again from heavy sediment, now liquid can be distilled.
It is important that the liquid is bright before distilling
providing most of the solids have been removed before distilling.
Turbos in the future
There are many manufacturers of Turbos and frankly, it needs a lot of know how to make a good turbo.
Our policy is to sell top quality. All Turbos we sell are of high quality only. For example, the nutrient of a certain turbo contains 22 different ingredients.
Some competitors have a product containing only one ingredient: ammonium phosphate. Another example: some competitors' yeast ferments much faster when one uses a mono sugar like grape sugar (glucose) or fruit sugar (fructose).
The Turbos we sell ferment sucrose (ordinary household sugar, a two-sugar) with the same speed. All our Turbos are also designed to make as few volatiles as possible. To make a good turbo you need a great deal of know-how. To make a bad turbo you need only bakers yeast and ammonium phosphate.
I am serious about this. The first widely sold turbo here, and probably in the whole world, was my product, SUPERJASTEN. I have not sold this in 1996, 1997, 1998 and 1999 because it was no longer, in my honest opinion, the best. Today I have sold this trademark and no longer sell this (still competitive) product. I have been a reseller for my competitors better Turbos those years.
Scandinavia is considered the world's leading market in essences, activated carbon and yeast. To give an example, one of our competitors has sold essences for 100 years. Many products have been invented here.
Now I am back with 5 new Turbos, it took 3 1/2 year and there is no better Turbos available worldwide. And if there will be, I will resell them.
For the future, yeast scientists are working very hard. The strains used today are natural and so it will be for a while. New strains will tolerate higher temperatures and higher alcohol contents and make less and less volatiles. After this, genetically manipulated strains will take over.
Then it will be possible to ferment 25% alcohol, a liqueur, maybe even more. How long this will take is impossible to know. My estimation is that it will occur within 9 years from today, but no sooner than 4 years......Gert Strand.
