How about sun tea? Lipton black tea is affordable and comes in a big box at pretty much any grocery store. I place about 4–5 bags of tea in a half-gallon jar in the sun for about 30–40 minutes (usually it’s much longer than that because I forget). Serve with ice and a lemon wedge, or stash it in the fridge for later. It’s a slow process, but I kind of like that it’s slow.