all it, tao foo, tauhu, tofu, soya bean curd, soy bean cheese, soy bean cake or whatever you like, it is officially called d˛ufu in China.
above - soya beans
left - fresh d˛ufu
What is d˛ufu?
d˛ufu is just one of the countless products made from soya bean (including the popular soya sauce of course). Soya bean is a major sauce of protein for the Chinese and is especially important in a vegetarian diet. Called meat for the poor, important in the diet as it is, it is never highly esteemed. So if you're trying to impress your traditional Chinese guests, leave that d˛ufu out of the menu, unless you can give it a fancy Chinese name of course!
photo below: extra firm spiced/flavoured d˛ufu
Why Chinese eat d˛ufu?
While Westerners eat d˛ufu because it contains all eight essential amino acids and plenty of other healthy stuff. We Chinese eat them because we've been eating d˛ufu for hundreds, perhaps thousands of years and because it is cheap(if you don't buy it from the health food store!), it has great texture, it is highly flexible(You can eat it fresh uncooked, stir fry it, boil it, steam it, deep fry it, grill it, stew it, smash it ...) and it is tasty.
How is d˛ufu made:
It's very simple, you can easily make it at home.
In brief, soya beana are soaked, pulverized, water added, juice strained and boiled(now you get soya bean milk), coagulant(Calcium Sulfate or Magnesium Chloride) added(now you get soft doufu), pressed to various firmness(now you get firm tofu). Take a look at soya bean milk and soft beancurd dessert recipes.
It can be further deep fried to become the spongy fried doufu which totally changes the texture, spiced(often with soya sauce, star anise or turmeric) or colored yellow, brown or maroon. Most are natural, many are slightly salted and some are sweet. Photo on the left shows natually home made air cured d˛ufu.
It can also be sliced into cubes, spiced and fermented(it maybe appropriate to describe it as cheese, see photo below), these are usually bottled. Do not confuse this with Malaysian/Indonesian tempe(fermented soya bean cake) which is made with whole boiled beans and available fresh.
Is fresh d˛ufu tastless?
While its taste is subtle and too bland for most like a potato, it certainly isn't tasteless. If you'd eaten freshly made doufu, you'll know what i mean. Fresh d˛ufu has a wonderful fragrant, you can smell it from a distant. In Asia, tofu is usually made, sold and used the day it's made, usually fresh from a bucket filled with water that is frequently changed. For those who are only exposed to packaged tofu, you're really missing out on the real thing.
firm, extra firm and soft d˛ufu
While fermented d˛ufu (photo left) is an important item in the Chinese kitchen, the d˛ufu known in the West are the fresh firm and soft(silky) types. Deep fried and spiced d˛ufu are sometimes available in speciality stores.
While firmness of d˛ufu varies with manufacturers, there is one basic way to tell if its firm or soft d˛ufu. If you could handle the d˛ufu easily without it crumbling and falling apart, it certainly is firm d˛ufu, otherwise it's soft(sometimes called silky) d˛ufu. The basic different between the two is the water content and texture. Most spiced d˛ufu are extra firm in order for them to withstand the extra handling.
While firm d˛ufu cannot be made any softer but soft d˛ufu can be made firmer by freezing and thawing, boiling in water, or pressing. These three methods change the texture of the d˛ufu in different ways. Freezing and thawing makes the d˛ufu more porous so that it soaks up flavourings easily. Pressing soft tofu dries it out and causes it to lose smooth "silky" texture.
D˛ufu may be stored in the refrigerator for up to three days covering in water. The water should be changed every day. However, it will loose its delicate flavour. Freezing is another method, but it will alter the texture totally and may not be desirable.