Some 30-ish years ago, I used to make my own tofu, and one of the steps is soaking the soybeans overnight. In warm weather, they frequently ‘fermented’ to the point of being quite bubbly before the steps of grinding, milking and boiling. I’m sure anything alive was killed in the process of boiling, of course. No tofu I have had since tastes as nice as fresh tofu still slightly warm from the coagulation and straining stages. Once it’s refrigerated, it becomes something entirely different.