Long before science could explain what happens in fermentation and distillation, people learned that if you set sugary liquid aside somewhere for a while, it would change flavour and make you feel jovial when consumed. Boiling these liquids and collecting the vapours concentrated this effect. And after being in a wooden cask, the common vessel for transporting just about anything, it picked up more flavours.

While scientists were still debating whether yeast was a living thing or a catalyst, brewers and distillers were making use of it, becoming successful where the natural microbes created good flavours.

Folk distilling is the collected lore on making spirits, passed down through generations of distillers. In countries with uninterrupted traditions, their methods survived. Some spirits are still made the same way, in the same place, with the same ingredients as they have been for centuries: genever, Italian amari, Armagnac, and certain whiskies.

“You can argue that