Professionals sniff out pungent smells in stinky tofu blocks

In a steel sink with liquid the color of tarmac gurgling in it, Zhou Chengrong slowly lowered his hands into it and gingerly fished out a chunk of bean curd with a gray hue on its edges.

The signature funky odor from hours of fermentation in a herb and spice-based brine "hit" Zhou in the nose.

However, the 44-year-old remained expressionless as he held the slab in his palms and took a deep breath to examine the smell.