豆腐 / Tofu - A Culmination of all of Daizu (Soybeans) Powers -
As the weather warms up, one of the foods that we want to eat more of is hiyayakko; a simple dish of chilled tōfu blocks served with various toppings. Even though a white, square block of tōfu wouldn't be considered a main dish, it really is central to the culture of Japanese cuisine. Taking a deeper look at tōfu, even its simple taste begins to feel a little more profound.
Tōfu is made from soybeans, which are low in calories yet high in protein with abundant nutritional value. An essential part of Japanese cuisine, tōfu is established as a popular health food not only here in Australia, but all over the world. There are many foods made from tōfu and there are lots of ways to enjoy it.
The History and Distribution of Tōfu
Tōfu’s roots are ancient and it is believed to have been created in China approximately 2000 years ago. It wasn't introduced into Japan until a long time later, between the Nara period (710 – 794 AD) and the Heian period (794 – 1185 AD) when monks and scholars travelled to China for diplomatic talks. It is a popular theory that these envoys brought tōfu back to Japan with them. At first it was a luxury ingredient reserved only for use in temples and the Imperial Court, but during the Edo period (1603 – 1867 AD) it finally began to be eaten by ordinary people.
In the Far East and Southeast Asia where foods made from soybeans are precious sources of protein, tōfu is a crucial part of the daily diet. Interestingly, apart from some pronunciation differences, tōfu has basically the same name throughout the whole region; it is written as ‘豆腐’ in both Japanese and Chinese, called ‘tobu’ along the Korean Peninsula, ‘tōfū’ in Myanmar, and ‘tōfu’ on Java.
A Woman’s Best Friend
Soybeans, the main ingredient of tōfu, are said to have health benefits such as suppressing the onset, and assisting in the treatment of illnesses such as cancer, high blood pressure, sclerosis of the arteries, heart disease and diabetes. In addition to this, soybeans contain extremely high amounts of isoflavone, a substance receiving attention worldwide for its properties that are similar to the female hormone oestrogen. Because of this, it is hoped that it will have beneficial effects on symptoms that result from menopausal disorders and other conditions caused by the reduction in estrogen.
In addition, compared to raw soybeans, the body is able to digest tōfu more efficiently, which means it can absorb the nutrients without wastage. It is said to promote the growth of good bacteria in your intestines, as well as increasing memory, and having beneficial effects on your metabolism, stress reduction, and skin, making it an incredible food to eat.
Varieties and Methods of Making Tōfu
When you think of tōfu, momen-dōfu (firm tōfu) and kinugoshi-tōfu (silken tōfu) spring to mind. As the Japanese name suggests, during the process of making momen-dōfu a momen (cotton) cloth is used to drain the moisture. Kinugoshi-tōfu, on the other hand, is made to have a smoother texture than momen-dōfu hence the reason it is called kinugoshi (kinu means silk and goshi is derived from the word kosu, meaning to strain).
Both momen and kinugoshi tōfu are essentially made by soaking soybeans in water until they are soft before crushing them, boiling the mixture and straining it to make tōnyū (soy milk). To this nigari (a liquid by-product of the process of making salt from seawater consisting mostly of magnesium chloride and calcium chloride) or another coagulant is added to set the mixture. Despite the manufacturing process being very similar, of the two, momen-dōfu contains a greater amount of protein. The reason the nutrients of the two types of tōfu vary is due to the following differences in their production.
Momen-dōfu is made by adding nigari or other setting agents to tōnyū and, when it has set to a relatively firm state, it is poured into a piece of cloth covering a small box frame with holes in it which is placed on a stand. Weights are laid on the mixture forcing the moisture out of it through the holes in the box, and it sets into tōfu.
In this manufacturing process, pressing the moisture concentrates the nutrients leading to an increase in protein, energy, lipids and other constituents compared to kinugoshi tōfu.
This type of tōfu is made by adding nigari or other setting agents to a richer blend of tōnyū and pouring it into a box with no holes, allowing it to set without straining off the water content. This creates a softer, smoother tōfu without the rough surface texture made by the cotton which momen-dōfu has. Kinugoshi-tōfu is Japan’s own, unique tōfu and is typically used in foods like hiyayakko.
Through straining off the water content, the water-soluble B vitamins and potassium also drain away, so kinugoshi-tōfu contains more of these than momen-dōfu.
Most of the tōfu sold in supermarkets is generally jūten-tōfu, also known as jūten-kinugoshi-tōfu. This type of tōfu is made by adding setting agents to cooled tōnyū and pouring it directly into a package before heating it to make it set. Most of this process is performed by machines making is possible mass-produce the tōfu, keeping costs down. Also, as the package is sealed airtight before being heat sterilised, it keeps fresher for longer.
Generally, if tōfu is eaten fried, stir-fried, steamed or deep-fried, firmer momen-dōfu is used. If it is eaten to enjoy the texture, such as in hiyayakko or salads, kinugoshi-tōfu is chosen. But, of course, this choice comes down to personal taste. One of tōfu’s appeals is that you can easily match it to your cooking or your mood.
Water is the Soul of Tōfu
Made of 80 to 90% water, tōfu really edible water . The quality of the water used is greatly responsible to the taste of the tōfu produced. Soft water is the most suitable water used to make tōfu as it brings out its natural taste and umami. The minerals in hard water, on the other hand, bond with the proteins and tend to make the tōfu hard. Because of this, when you make tōfu at home, it’s best to use the softest water you can.
On the corner of some tōfu…
In Japan, tōfu is sometimes used as a metaphor for very soft things. The saying ‘hit your head on the corner of some tōfu and die’ is used to imply that someone is very stupid. It comes from the meaning that they would try to kill themselves by hitting their head on a piece of tōfu, something that would be impossible due to its softness.
Ingredients associated with Tōfu
Okara (soy pulp) and tōnyū are two of tōfu’s companions made during its manufacturing process. They are both health foods full of nutrients so they are perfect to enjoy with tōfu.
Tōnyū (Soy Milk)
The basis of tōfu, tōnyū has almost the same great balance of nutrients. It is recognised for helping to reduce cholesterol levels in your blood, improving intestinal conditions, as well as replenishing iron levels. There are different varieties of tōnyū differentiated by the amount of soy solids contained; tōnyū contains at least 8%, chōsei-tōnyū (flavoured tōnyū) contains at least 6%, while tōnyū-inryō (tōnyū drinks) contain a minimum of 4%. Cosmetics containing the whitening agents of tōnyū, such as skin lotions, soaps and face packs, are also popular.
Okara is the husk of the soybeans (a husk is called ‘kara’ in Japanese, hence the name) and all of the pulp after the tōnyū has been squeezed out. It is also known as ‘unohana’. Even though it is a ‘waste product’, it is a health food containing an abundance of soybean fibre. It improves bowel movement and removes the toxins that accumulate in the intestines. The lecithin contained in okara dissolves the cholesterol built up in blood vessels and also protects against the hardening of arteries, in addition to improving memory and concentration, and fighting off dementia.
Further processing of tōfu creates various other delicious foods! Some of these include abura-age which is momen-dōfu that has been drained, thinly sliced and slowly deep-fried at a low temperature; atsu-age, drained momen-dōfu deep-fried at a high temperature; kōyadōfu, drained momen-dōfu that has been freeze-dried; and ganmodoki which is momen-dōfu that has been crumbled and drained, mixed with julienned vegetables and grated yam and formed into a patty shape before being slowly deep-fried at a low temperature.
Live more healthily with tōfu!
Photography assistance: LITTLE TOKYO