Difference between revisions of "Distilling"

Distilling Terms

aging - the storage of distilled spirits in order to allow it to mature and mellow in flavor while absorbing some of the flavor and color of the wood barrel in which it was kept (though alcohol can also be aged in glazed ceramic pots)

column still - a still in which the mash or wash is poured into a column full of porous plates and can be continuously distilled (as versus a pot still which can only distill one batch at a time), can produce high alcohol content as each stage acts as a separate pot still and therefore can reach a final product of up to 96% alcohol

condensation - when a gas or vapor, such as steam, becomes a liquid

condenser - a vertical pipe connected to the Lyne arm of a still through which vapor passes and is cooled as it travels through a coil surrounded by cool water in order to cause the vapor to condense back into a liquid and dip out into the waiting vessel

congener - impurities found in the mash or wash which are not the desired alcohol

cut - the point in which the distiller changes collection containers during the distillation process in order to separate out the foreshot, head, heart and tail

distillate - the liquid that is collected from condensed vapor in a still

distillation - the process of converting a liquid into steam, and then collecting it's condensation in order to get a more pure form of the liquid

distillation column - part of a still which is usually filled with perforated plates through which the steam from the mash passes through on it's way to the Lyne arm, this column can also be curved (in which case it is called a swans neck) in order to catch impurities and eliminate the need for inserted plates

ethanol - the clear liquid produced during fermentation; alcohol

fermentation - the conversion of sugars into carbon dioxide and alcohol by yeast

fermenter - the container in which mash or wash is fermented, usually made of metal

foreshot - the first liquid to come from the distilling process, usually discarded or re-distilled because of the high content of volatile and unwanted compounds

fusel oil - a type of congener made up of volatile alcohols, fatty acids, and acid compounds that can be the cause of hang overs

head - impurities which are collected from the distilling process after the foreshot and before the heart or tail, some of the late head might be used to add flavor to the alcohol, but most will likely be re-distilled

heart/middle run - this is the desired alcohol collected during the distillation process and comes after the foreshot and head but before the tail

Lyne arm - part of a still through with vapor passes which connects the top of a distillation column to the top of the condenser

malt - a grain which has been steeped in order for it to germinate before the process is halted and the grain dried to be used later in brewing or distilling mash

mash/wash - a mixture of grains and water that is heated in order to promote fermentation and is later put into a still to be distilled

pot still - a still with a lower pot in which mash is heated, allowing the steam to travel up into a distillation column, through the Lyne arm, and down into a condenser where it will turn into liquid and be collected

proof - the amount of alcohol measured in .5% alcohol to volume (therefore, 30 proof is 15% alcohol)

How Distilling Works

STEP 1 - THE FERMENTATION PROCESS

In a large container, called simply the fermenter, starches (usually grains, but not always) are combined with water and yeast, which is then heated. The heating process converts the starches into sugars, which the yeast feed on and in turn convert into alcohol. This process leaves you with a wash, a fully fermented mixture that is roughly 10% alcohol. It is this liquid that is then poured into the still.

STEP 2 - THE DISTILLATION PROCESS (POT STILL)

A still is made up of several parts. On the bottom is the pot, a bulbous, double-lined metal pot in which the wash is poured. The liquid is then heated to 173f (79c), the temperature at which alcohol boils, and then to the temperature required for water to boil, which would be 212f (100c). A mixture of water and alcohol steam rises up from the pot into the distillation column.

The distillation column is a long column of copper filled with perforated plates. As the steam climbs up the column, it moves into cooler temperatures, which causes it to condense. Heavier particles, such as impurities, condense onto the plates and fall back into the heated wash, leaving less impurities and more alcohol in the vapors that eventually reach the top of the column. This vapor moves into the Lyne arm.

The Lyne arm is a horizontal pipe that the vapor travels through on it's way to the condenser. The condenser is made up of a spiraling pipe for the vapor to pass through which is contained inside a long pipe filled with cool water. As the vapor passes through the spiral pipe, the water cools the surface of it, causing the alcohol vapor to condense back into a clear liquid and drip down the length of the pipe and out into a container. This liquid is called the distillate.

STEP 3: MAKING THE FINAL PRODUCT

There are three parts to the distillate. The head is the impurities that actually boil at a lower point than alcohol. This generally makes up the first 5% of the run. Then the heart comes out, which is the strong, nearly pure alcohol that is the base you are looking for. Finally, the tail is the lower concentration of alcohol which also contains contaminate that evaporate at a higher temperature. A lot of the flavor in the final product can come from the wanted impurities, or congeners that are found in the head. The key to being a good distiller is knowing when to start collecting the heart that leaves just enough of the head for flavor, and when to stop collecting it to leave out the tasteless tail. Depending on the still, the alcohol content of the distillate should be between 60 and 80% for a pot still, and up to 90% in a column still. This is later diluted with water in the final stage.

What you then do with the heart depends on the alcohol you are making. To finish it, there are a few different choices:

Redistilling - Putting the heart back into a distiller creates a higher alcohol content and fewer unwanted impurities, which should improve the flavor.

Filtering - After diluting the distillate to less than 50% alcohol, it is passed through a carbon filter in order to trap any remaining impurities. This is then passed through a paper filter before being put into a final container.

Flavoring - This is the point at which fruit or spices can be soaked in the distillate in order to infuse the alcohol with a different flavor. (This is what Vintners who specialize in Liquors are especially suited for).