So, prominent example: What is lacka, how is that made? ^ Onion liqueur? Yuck!
Tubers are more like potatoes and Lacka is basically PS vodka.
However, back when I played Telnavi I actually did do research on brewing and liquor, which I've forgotten a lot of, but wikipedia as always helped. This comes from the brewing page.
The basic ingredients of beer are water; a starch source, such as malted barley, which is able to be fermented (converted into alcohol); a brewer's yeast to produce the fermentation; and a flavouring, such as hops.[4] A secondary starch source (an adjunct) may be used, such as maize (corn), rice or sugar...
With that in mind, available useful ingredients in game or in settings: Wheat, Barley, Strimptor(sugar), Berries and fruit such as joopiner and macca, Yeast of some sort (there has to be yeast to make bread and beer), water. So now... what interesting things can we come up with with what we have here?

Hmm... probably easier to come up with drink names.
How about:
- Airy Berries - Berry flavored drink favored by Klyros
- Clackerhead - Hard liquor drink that you'd have to have a head as hard as a clacker to drink
- Irongut - a reddish non alcoholic drink for Kran that is flavored heavily by Kran and contains a mineral that gets them drunk. Favorite of miners and other common worker Kran.
- Grendol Guts - An ugly looking drink that is a combination of different colored drinks. Reminiscent of an Alien Brain Hemorrhage which you can google a picture of
- Lady's Charm - A drink mixing a sweet fruit juice and Charmflower extract or charmflower liqueur. Pink or purple drink garnished with a charmflower. Needless to say, a girl drink
Hmm... now I wish I could get in game and look at what ingredients we have to work with.