Dave, at Via Negativa, clued me in a creative use for beer: moss graffiti art ingredient. The concept is pretty simple. In a bucket, mix a can of beer with a half teaspoon of sugar and a handful of broken up moss. Stir well or use a blender if you prefer. Pour it in any manner of of dispensing system, such as a spray bottle or watering can, or dip a paint brush in a bucket of the final mix. Spray or paint on the liquid in any design you fancy. The result is moss art. It will hold the design for a while until eventually the new moss growth will distort it out of recognition.
The best kind of beer to use it homebrew from a batch that went awry or that can of cheap fizz-water that’s been cowering at the back of the bottom drawer in the refrigerator ever since your brother-in-law brought it to your holiday party.