From Grain to Glass: A Comprehensive Look at the Distilling Process

The Malting Process

Three steps make up the malting process: steeping, germination, and kilning. It’s a way to prepare cereal grains like barley, wheat, rye, and corn for brewing by making them sprout and then heating them to stop the growth and provide the grain with a specific toastiness.

The germination step speeds brewing because enzymes kick into high gear to produce soluble starch, malt sugars, and usable yeast nutrients. The quality of the grain will also contribute to its flavor. For example, short, plump grains with a wide scutellum will produce more extract than long, spindly grains with a narrow scutellum.

After being malted, the grain is ground coarsely in a mill and combined with hot water in a mashing tun to create a mash. The mashing removes the remaining starches and converts them into sugars, which are then fermented by yeast into alcohol. The resulting liquid, known as wort, is then put through the distillation process to increase the concentration of its alcohol.

The Fermentation Process

Fermentation is an organism’s central metabolic process that transforms sugar into different substances, such as acids and alcohol. Humans have used this well-known natural process for thousands of years to create alcoholic beverages, bread, and other fermented products.

Yeast feeds on sugar and, as a result, releases alcohol and carbon dioxide. These are the primary ingredients for beer, wine, and other alcoholic drinks. However, many countries produce other alcoholic drinks using various raw materials.

During distillation, heating, and chilling, a liquid’s components are separated into pure alcohol by boiling water vapor. The vapor from the alcohol-water mixture is then condensed to make it more concentrated. This allows the final product to reach 80-95 percent azeotropic concentration. This is the highest possible alcohol concentration in a continuous distillation system. However, other distillation methods can produce higher-proof spirits, as discussed below.

The Distillation Process

Distillation is a separation process that separates a liquid mixture by selective evaporation and condensation. It depends on the variations in the boiling points of the constituent parts of the mixture. It can be done on a laboratory scale or an industrial scale. It can also be done by continuous distillation in petrochemical plants and oil refineries.

Laboratory scale distillations are usually run as batch distillations. The equipment consists of a pot or reboiler in which the raw materials are heated, a condenser to cool the vapor back to a liquid, and a receiver in which the distillate is collected.

The main distillation component is ethanol (C2H5OH), separated from the heads and tails during distillation. The ethanol is refined by further distillation to produce high-purity spirits such as whisky. The other substances found in the heads and tails have unpleasant odors and tastes and are harmful to health at higher levels. They are sometimes concentrated through freeze distillation, which is not technically a form of distillation but concentrates poisonous compounds like true distillation.

The Matured Spirits Process

While it may seem simple, aging is one of the most critical and romanticized aspects of the production of spirits. It can add rich amber color, vanilla and oaky flavors, and a range of other nuances that contribute to the complexity and flavor of a spirit.

While ethanol, the potable alcohol that distillers seek to capture, has a high boiling point, other congeners with lower boiling points evaporate first. These undesirable compounds are known as ‘heads,’ they are usually discarded or re-distilled. Next come the desirable ‘hearts,’ which are separated and saved.

The last step is the aging of barrels traditionally made of oak. The oak’s exact species, the barrel’s size, and whether it is new or used are all factors that determine how a spirit will develop during maturation.