Potato distillery
In the grain and potato distillery , starchy agricultural raw materials such as potatoes and grain are processed into agricultural alcohol for consumption, medicine, pharmacy and cosmetics as well as for the production of vinegar. There are agricultural (often organized in cooperatives) and industrial burners. Usually it is a closure distillery .
raw materials
All types of starchy agricultural products such as
- Potatoes and dried potato derivatives such as rolled potato flour, potato flakes, schnitzel and slices
- Grain : Wheat , rye , buckwheat , barley , oats , millet and their derivatives, but above all triticale and corn
- rarer roots and tubers : cassava roots , potatoes , couch grass , chestnuts and their derivatives
Preparation and digestion of raw materials
First, the long-chain starch has to be broken down into yeast-usable, short-chain fragments, ie saccharified. The strength must be unlocked, gelatinized and loosened. The prerequisite for this is the sufficient availability of water, depending on the nature of the raw material. The raw materials are crushed, mixed with water and then steamed under pressure in stainless steel containers. One speaks of mashing .
Fermentation process
Pure yeasts are added to ferment the sugar into alcohol , using the yeast yeast process, lactic acid process, sulfuric acid process or by means of continuous yeast flow.
The classic fermentation time is three days or 68 hours (fermentation about 20 hours, main fermentation about 18 hours, secondary fermentation about 30 hours), longer times are not advantageous. The temperature is between 20 and 36 ° C.
Continuous distillation
The burning of the mash takes place in pot stills with a column of many bubble trays. In apparatus with a dephlegmator and tube cooler, an alcohol strength of > 85% can be achieved in one operation.
Spirit counter
Since the alcohol production is subject to strict controls by the customs authorities , the amount and strength of the alcohol or raw spirit produced is meticulously recorded. Special dial indicators are used for this.
Recycle the stillage
The sour mash or stillage is used as fodder, which, however, requires livestock farming, or raw material for biogas production. In agricultural distilleries, the use of cattle feed in their own operations, as well as the exclusive use of self-produced raw materials, is usually prescribed by law.
literature
- Heinrich Kreipe: Grain and potato distillery . 3. Edition. Eugen Ulmer, Stuttgart 1981, ISBN 3-8001-5810-8 .