Written by DEVON TREVATHAN
VACUUM DISTILLATION SIMPLIFIED V
acuum distillation is still a rarity in the industry; the vast majority of producers use traditional distillation methods to separate alcohol and other molecules from a water mixture. Whereas high heat is the catalyst to reaction in traditional or simple distillation, vacuum distillation adjusts the atmospheric pressure, lowering it and thus depressing the boiling points of certain elements in the wash. This can have a number of benefits. For distillation using high temperatures, the time of the process is often extended, the efficiency compromised, and flavor compounds may decompose or be subject to changes. One obvious use of vacuum distillation would be to distill fresh ingredients such as flowers. Dwayne Bershaw, lecturer of enology at Cornell University, explains that some volatiles can get ‘cooked’ because of the temperatures required to do alcohol distillation at atmospheric pressure. He further explains, “But by lowering that pressure you’re also lowering the boiling temperature of the solution, so hopefully you’re not cooking some really delicate aromatics that you think you might be getting.” It can be difficult to capture the flavors of fresh honeysuckle or lavender, for instance, when you distill those using heat. The high temperature can result in unsavory character from the ingredients cooking, restricting the full availability of potential flavors.
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Using vacuum distillation creates the opportunity for a talented distiller to access a different segment of the flavor spectrum. This is important for producers who regularly use fresh ingredients in their distillation. “When I hear about [vacuum distillation], I mostly think of people in the gin production category, stuff like that, where they’re trying to get these really interesting aroma volatiles,” said Bershaw. Many distillers who want to incorporate the flavors of ingredients like cucumber or florals might opt to use extracts, vapor distillation, or maceration, however, each of these methods come with some drawbacks. Instead, a distiller could reach for their tabletop vacuum system, which can distill ethanol at room temperature by reducing the pressure inside the vessel to nearly zero. Once distillation has begun, the ethanol vapor travels through a cooling coil
Vacuum distillation can be used in tandem with other distilling techniques, such as vapor distillation, to make an elegant and subtle spirit.
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