Ice brewing

The AC could slow down the ice melt a little but I don’t think its a significant enough factor to worry about. The idea is to let the ice cubes melt naturally, however long that might take.

You can absolutely ice brew in a teacup or any vessel for that matter. No kyusu or anything fancy required. I also cold brew using a Japanese teacup and a plastic lid and then strain into a thermos or drinking glass. Turns out great every time.