"Stinky tofu stinks" because in the process of fermentation, pickling and post-fermentation, protein contained in tofu is decomposed by protease, and sulfur-containing amino acids contained in tofu are also fully hydrolyzed, resulting in a compound called hydrogen sulfide (H2S) with a pungent smell. Protein decomposes to produce amino acids, which are delicious, so they are "delicious". The production process of yellow stinky tofu is basically the same as that of black stinky tofu, but the formula of brine prepared by different sellers is different, so the stinky tofu sold by different merchants we taste is also different.