To understand how this magic works, we need to explain how distillation works. Distillation is the process of purifying a liquid through evaporation and condensation. Many modern distilleries use column stills for continuous distillation (which is different from triple distillation), but we’ll focus on pot stills here because they’re easier to understand.
After fermentation, the bourbon mash is placed into a large pot and heated. As the liquid’s temperature rises, the alcohol and water begin to evaporate. This vapor rises through tubes and is sent to a second pot where it cools and turns back into a liquid. This allows the distiller to concentrate the product, increasing its alcohol content.
The purpose of this little science lesson is to explain why bourbon is gluten-free: because the gluten doesn’t evaporate. When the distillation process is finished, all of the gluten remains in the first pot. That’s why salt water can be distilled into fresh water, because the salt doesn’t evaporate and move to the second pot. Although less common in bourbon, there are also whiskeys that are triple-distilled, which means an even purer end product, but only one distillation is needed to remove the gluten. Depending on the severity of your gluten intolerance, unintentional cross-contamination is theoretically possible, so you may want to be careful anyway, as some suggest, but cross-contamination is a different issue entirely.
