What's this on my tofu gan/savory baked tofu?

[banjoboy]

Whenever I buy tofu gan at my local chinese market, if I leave it in my fridge for more than a few weeks, a viscous sort of goo forms around it in the plastic wrap. It has no smell, washes off the tofu easily, and as far as I can tell, has no taste either (at least once I've cooked it.)

Anyone know what it is? Should I toss the tofu gan and replace with a "fresher" supply?

[Cheeryvisage]

It happens. I think it may be the beginning of mold. I slice the gooey outside off before cooking the tofu and it's no problem.

If mold actually forms though, throw the entire thing away.