I’ve made Tofu before, using the Nigari Salts to make Homemade Tofu. This method uses a much easier coagulant, lemon!
Nigari salts can be made from sea-salt. They’re difficult to find, and in shops, and so you might end up having to make them yourself.
Lemon on the other hand, is trivial to get. I didn’t realize it could be made from lemon, but now I know, I’ll be making it myself more often!