Gin is mostly made from grains, the juniper berry is for flavor. So it would be perfect if that hint also had '(flavoring)' added. By the way, your quizzes deserve more attention!
Thanks to Jetpunk, I've learned that the word corn in British English is used for cereal grains in general, including wheat, oats, and barley. I'm guessing that's leontodon's frame of reference.
As a Polish girl — we make vodka in Poland mostly of wheat, potato vodka in Poland is „bimber” (homemade alcohol drink, usually more alcoholic than vodka, about 70-80%) but I know it’s made with potatoes also in other slavic countries like Russia
If you said wheat then it is the grain used to make bread.