After making soya bean milk at home, with okara and yuba as by-products, the next logical thing to try was making tofu. It was so easy and gave me a great sense of satisfaction (^_^). I refered to the ‘bible’ of tofu by William Shurtleff and Akiko Aoyagi.
For the coagulant, I used nigari, purchased from a health food store (Nature’s Glory). This is the coagulant usually used in Japan comprising mostly magnesium sulphate and is made by evaporating sea water. Shurtleff advises that ‘calcium sulfate, a fine white powder, is sometimes mislabelled in the West and sold as nigari. The latter usually has a coarse, granular or crystalline texture, natural nigari is beige and refined nigari is white.’
Aside from nigari, Epsom salts/magnesium sulphate (a popular antidote for food intolerance reactions!), gypsum/calcium sulphate, lemon or lime juice or vinegar can also be used as coagulants. The coagulant used for Chinese tofu is gypsum/calcium sulphate. Glucono delta-lactone (GDL) is a naturally occurring organic acid that is used to produce ‘silken’ tofu. Read more in my earlier post on coagulants for tofu.
The choice of coagulant affects the texture and taste of the tofu, as does the amount used. For firmer tofu, use nigari; softer tofu, use calcium sulphate. The amount of pressure used when pressing the tofu and the length of time it’s pressed also influences how soft or firm it is.
For a quantity of soya bean milk using 1 1/2 cups soya beans + 16 cups water, Shurtleff suggests:
* for subtly sweet, nigari tofu: 2 tsp natural nigari (magnesium chloride) or refined nigari (calcium chloride)
* for mild, soft tofu: 2 tsp Epsom salts (magnesium sulphate) or gypsum (calcium sulphate)
* for subtly tart or sour tofu: 4 Tbs freshly squeezed lemon or lime juice or 3 Tbs apple cider vinegar.
Here’s what I did:
To use nigari, dissolve 1 tsp nigari in 1 cup water. Reduce quantities as appropriate.
For every 4 cups soya bean milk, use 1/2 cup nigari solution.
1) Start by making soya bean milk. See the detailed instructions at Just Hungry.
2) After boiling the milk for 5 mins, remove from heat and leave to cool for another five minutes.
3) Slowly add coagulant and stir gently. Watch the curds form.
4) Leave for 10 mins and allow curds to settle in the bottom.
5) Prepare tofu-mould. Ideally, use a square/rectangular box with holes. If not, you can improvise with a colander but you will end up with an unevenly-shaped piece of tofu (see photo below). Next time, I will try using one of those plastic boxes for storing ready-made tofu from Daiso, or by Lock & Lock, which have an inner container or even non-tofu specific Daiso plastic containers with inner strainers.
6) Place a piece of muslin cloth into the colander/mould.
7) Gently scoop the curds into the muslin cloth. Squeeze out whey liquid.
8) Fold the cloth over the top of the curds.
9) Place a plate or something flat on top of the curds, and weight it down. I used an unopened 1kg bag of rice and balanced a heavy tin can on top.
10) Leave to set. The firmness of the tofu depends on how long it is left to set and how heavily it is weighted down. I left mine for about 3hrs and ended up with the firm consistency of taukwa, which can be easily fried.
This small slab (about 12cm or 5 inches across) was made from 2 cups of soya bean milk.
What to do with the whey liquid? If you’ve added the correct amount of coagulant, the whey will be amber-coloured and taste sweetish. Too little coagulant and the whey will be cloudy from bits of loose curds; too much coagulant and the whey will taste bitter.
Don’t throw away the whey as it’s full of B vitamin nutrients, protein (9% of the protein originally found in the dry soya beans) and natural sugars. You can add it to soup, use in cooking in place of other liquids, or even use it as a biodegradable soap! According to Shurtleff, traditional tofu shops in Japan use the whey to wash their equipment at the end of the day because the soy lecithin in whey cuts through fats. Whey can also be used as a facial wash or shampoo (how’s that for homemade, environmentally-friendly, chemical-free toiletries ☺?), washing and polishing wooden floors or woodwork to give a natural, seasoned look, as well as a plant nutrient.
Please check out Just Hungry’s detailed tofu-making instructions complete with step-by-step photos (she’s got a real tofu press!).
The comprehensive Wikipedia entry on tofu.
Read about the history of tofu in China here.
Don’t forget to check out my postscript to this entry, with many more links, including how to make your own tofu mould/press from a used milk carton!