The Art of Whiskey Making, Part 1: Fermentation

Every step and ingredient in fermentation influences all spirits profoundly. Listen in as master distillers Danny Kahn (Barton 1792 Distillery) and Steve Nally (Bardstown Bourbon Company) describe how the simple interaction between grain sugars and yeast create the complex and unmistakable flavors and aromas bourbon drinkers love.

[stevecoomes]

These dudes are brilliant. Tell us what you're learning about fermentation that you didn't know about.

[FireontheMountain]

Bacteria is not the enemy, but it can be. Gram-positive bacteria are a part of every single distillery's house flavor because bacteria is far more prevalent than wild yeast, and malted barley tends to contribute bacteria to a mash. Malted barley is usually added around 145 degrees Fahrenheit, which is not high enough to sterilize that mash and destroy that bacteria. Lactic acid bacteria (LAB) can steal sugar away from the yeast (affecting final yields) and can contribute too much acid during fermentation, but the organic acids produced during fermentation help produce esters, which are compounds that can positively (or negatively) affect aroma and flavor. One can encourage or discourage the development of LAB during the fermentation, depending on the types of esters developed/desired and for targeted final yield, and there are distilleries that inoculate their mash with bacteria. A healthier, stronger yeast population will generally prevent too much contamination from bacteria or even wild yeast strains.