Alcohol Distillation and Its Impact on Agriculture
Distillation may seem straightforward at first, but actually carrying it out requires many different tools and processes. At its heart is congeners – those organic chemical compounds such as alcohols, aldehydes, acids and esters collectively known as flavors – which give spirits their individual characteristics, both good and bad. Distillers with the skill to capture and select these key congeners account for all of the various styles available today – Harold McGee noted this perfectly in On Food and Cooking when speaking of proof as being equaling flavor in his book On Food and Cooking!
Farmers long recognized the potential of distilling before today’s farm to table movements made farmers markets and home canning trendy traditions. Fuel alcohol makes sense from an agricultural perspective as a viable replacement to fossil fuels as it can be produced profitably using crop and forest residues that would have otherwise been fed back into animals or burned to generate heat or electricity.
At present, there are two general distillation processes which seem suited for small-scale fuel alcohol production using existing technology. One is a continuous-feed distillation column system in which beer is continuously pumped through a distillation column for concentration purposes. Pot-type distillation involves boiling beer directly in place to evaporate alcohol and water vapors before forcing them upward into a distillation column for concentration. Both systems require sophisticated equipment including pumps that move liquid between containers and columns as well as reboilers or steam generators which supply energy needed to bring liquid back to equilibrium with its vapor state.