Contents
One of the optional, but recommended stages of fruit, sugar and grain moonshine. Wash degassing is a set of measures aimed at removing carbon dioxide in the inner layers before distillation.
Theory
During fermentation, yeast converts sugar into alcohol and carbon dioxide – one molecule of glucose is converted into two molecules of ethanol (C2H5OH) and two molecules of carbon dioxide (CO2). In order not to create excess pressure in the tank, carbon dioxide is removed through the tube of a water seal (a water lock that prevents oxygen from entering inside).
When fermentation wanes, the pressure inside decreases and the gas no longer comes out so actively. At the very end, some of it will definitely remain in the inner layers of the liquid. The concentration of CO2 in the finished mash depends on the type of raw material (most of all in grain mash), the duration and temperature of fermentation.
In carbonated alcoholic beverages such as beer, champagne or cider, some carbon dioxide is mandatory (sometimes a short re-fermentation is started for natural saturation with gas), because it gives a characteristic fizz and bubbles, but in ordinary wines and mashes, gas is removed artificially.
The degassing of the mash minimizes the risk of intense foaming during heating, which is the cause of the “flooding” of the moonshine still (the distillate enters the receiving tank unevenly, characteristic “spitting” appears) and splashing – parts of the mash and foam get into the coil, which leads to clouding of the moonshine.
Theoretically, if you leave the fermentation tank open, after a while the gas will come out on its own, but with access to air, acetic bacteria will become active and the mash will begin to turn sour, which will worsen the quality of the moonshine and reduce the yield.
Universal step-by-step instructions for degassing mash
1. After the end of fermentation, it is imperative to drain the mash from the sediment (decant) – pour the liquid part through a tube into another container.
2. There are two methods to degas the mash: temperature (heating) and mechanical (mixing). The choice depends on the amount of raw materials and a set of tools. The efficiency is the same.
Degassing by heating
Pour the mash into a can, pan or bucket, the wider the diameter of the neck, the better. The container must be enameled or stainless steel. You can use a moonshine cube. Heat the mash quickly to 50°C, stirring occasionally. When the hissing disappears and no bubbles stand out from the bottom, remove from the stove.
The short duration of the process and the high temperature will not allow the mash to sour. The disadvantage of the method is that it is difficult to pour and heat large batches, and besides, there are not always suitable metal containers.
Mechanical degassing
Easier and faster than the temperature method, but requires a drill (perforator) with a construction attachment or an aquarium pump.
In the first case, it is enough to mix the mash with a drill with a nozzle for 3-7 minutes until the smell of carbon dioxide disappears.
Attention! Mix the mash only in plastic barrels.
The second option is to lower an aquarium pump (household pump) with a capacity of 90-140 liters per hour into a container with mash drained from the sediment. Depending on the volume of mash and pump power, degassing will take 2-8 hours.
3. Degassed mash can be clarified with bentonite, gelatin or hibiscus tea. Clarification removes yeast residues and other impurities, improving the quality of moonshine.
4. After the removal of carbon dioxide, the distillation (distillation) technique does not change, but it is allowed to fill the cube by 80-85% with correctly degassed and preferably clarified mash and not by 70-75% as per the standard, leaving a free reserve only for expansion of the liquid from heating.