“Why copper?” a lot of visitors to our tasting room ask.
There are a few reasons why copper is considered the preferred metal for stills. It’s malleable, so it’s a good metal to work with to achieve the distinctive and functionally important curves in the pot still. Copper is also an excellent conductor of heat, so it makes an efficient vessel for boiling liquids.
But the main advantage of copper over other materials is that copper reacts with alcohol on a molecular level, making the final spirit taste better. A natural by-product of yeast during fermentation is sulfur, so the wash that goes into the still contains sulfur. When the sulfur comes in contact with the copper, it binds at a molecular level and becomes copper sulfate stuck to the side of the still – removing the undesirable sulfur taste and smell from the distilled liquid.
We scrub the copper sulfate out of the stills between each distillation, so over time, the interior copper will wear down and have to be replaced or repaired. But our copper stills will give us many years of production before the walls are too thin for distilling. (And thus, copper works…)