What is tofu?
Tofu is an extremely versatile ingredient often found in asian cooking and can be used in both sweet and savoury dishes. Tofu has been around for over 2,000 years and is said to have first originated in China. The common known English word of tofu originates from the Japanese word of tōfu (豆腐) which itself originates from the Chinese dòufu (豆腐) and literally translates to ‘bean’ 豆 ‘curdled’ 腐.
It was first discovered when sea water was added accidentally to ground soy beans and this mixture curdled into the early forms of tofu. Since then the process has been somewhat refined but the production of tofu comes down to three essential steps.
1. The soy milk is extracted from soy beans
2. A coagulant, either salt or acid, is added to the soy milk to form solid curds
3. The curds are then set into blocks which hold their shape.
Depending on how much moisture is removed in the final stage of pressing/draining determines the texture of the finished tofu. There are 4 main levels of firmness with tofu that are used in different dishes accordingly. Tofu with a higher water content is known as ‘extra soft’ and has a similar consistency to natural yogurt. The next is ‘soft’ or ‘silken’ which holds its shape out of the container but has the consistency of a very soft jelly that has very little resistance. The third level is ‘firm’ which while still moist, has resistance when pressed and has a similar consistency to cheese. The most rigid tofu commonly found is ‘extra firm’ which has a rubber like texture that is not dissimilar to cooked meat.
What does tofu taste like?
Many people comment that tofu is very bland or has no taste. Of course the flavour of the tofu you eat, depends on it’s origins and qualities. Processed tofu often has little to no flavour, whilst fresh tofu has a subtle flavour of soybeans. If the soy used in the tofu you are eating has been made with a hot grinding process, it is likely that the flavour will be very bland as the heat affects the enzymes and reduce any flavour or odour. Soy that has been processed for tofu using a cool grinding process retains more of the bean flavour as the enzyme reaction has not been triggered by heat.
The fact that tofu has a very subtle flavour, yet is healthy and comes in a range of textures, means that it is suited to a variety of dishes and is an excellent base for a dish for which you can add stronger flavours.
What is tofu made from?
Tofu is a very simple ingredient itself and it is made from using only a very few simple ingredients and processes. It is made from simmering soy milk and a coagulant (either a salt or acid) which helps it to solidify it into a block. the mixture is then drained to separate the curds from the whey in a similar process of dairy cheese production.
The base ingredient, soy milk, is made from soaking dried soy beans in water before they are boiled. The boiled liquid is then filtered with the result being basic soy milk.
Salt used as a coagulant for tofu can come from a variety of sources. Common sources of salt coagulants are gypsum (calcium sulphate) which has been mined from the earth and evaporated seawater (magnesium chloride and calcium chloride). Fresh sea water can also be used to curdle the soy milk and produce tofu. The use of salts in the production of tofu results in little change to the overall taste of the product.
Acids used as coagulants for tofu can be either vinegars or citric acid. The result of using acids like these in tofu production is a very smooth and soft product, however the taste can be affected by the use of stronger flavoured additives.
What to do with tofu?
This is a good question to ask! There are seemingly endless dishes that can be made using this versatile ingredient. As tofu developed in China, before spreading to Korea and then Japan, each country treats tofu in different ways which represent the local cuisines. The result is a vast range of dishes spanning many different countries all based around one common ingredient. Tofu now also finds it’s place in western dishes as a replacement for meat.
A common and simple Japanese preparation is to simply dress cold soft tofu with freshly grated ginger, thinly sliced green onions and soy sauce. Often shavings of smoked dried tuna (katsuobushi) are added for extra seasoning and the result is the dish referred to as hiyayakko.
If you prefer a hot dish, firmer tofu can be lightly floured with corn or potato starch and then deep fried before being served with a warm dressing of dashi and green onion to create the Japanese dish of agedashi tofu.
Cubes of firm tofu can be added to Japanese miso soup and extra soft or soft tofus can be sweetened with sugar or fruits for creamy desserts. There truly is an endless array of methods for preparing tofu that take it from a unfamiliar white block to an inexpensive and healthy addition to your diet.