I started freezing tofu by chance; I had three blocks of tofu in my fridge back in December and as I was leaving the country for a month, I didn't want them to go bad in my absence. I put them in the freezer and crossed my fingers, hoping for the best. Fast forward more than a month and I thawed the tofu out in the fridge. The consistency had definitely changed; the tofu was a little drier, more chewy. What was interesting though is that after freezing/thawing, the tofu absorbed marinades much, much better, and as a result, became more flavorable. Also, it was easier to get the moisture out of the block and hence, it would fry up more quickly in the wok. So if you're a tofu eater, I definitely recommend trying the freezing technique and see how it works for you. The only downside is that it takes a LONG time to thaw the tofu in the fridge; a warm water bath is a good option if you need it more quickly than that.