"Virtually anything that produces sugar -- fruit and grains -- can be used distilled, fermented or drunk," Stewart said in an interview. "Most people get involved with the mixers."
Fermenting -- adding yeasts to turn plant sugars into alcohol -- came first, she said. High-proof beverage alcohol (20 percent and above) came later with distillation, or heating fermented liquids into a vapor and then re-condensing that into a more concentrated mix.
Know your plants. "Understand what you're doing if you're out there gleaning," Stewart said. "A lot of plants become solvents when mixed with alcohol. Don't pick anything that might become potentially deadly."
A dizzying array of plants has been converted into alcohol over the ages, everything from agave (tequila) to yams (beer and vodka). Many plants are used primarily as garnishes, such as spearmint (mint julep), olives (martini) and cherries (Manhattan).
