But have you ever noticed that cooking rice at home takes at least half an hour to wash, soak, and steam it in a pot?

For self-heating rice, you only need to pour water, put in the heating bag, and it will be ready in 15 minutes.

Why is it so magical?

01 From military rations to rations, the past and present life of instant rice

Like many convenience foods, self-heating rice was originally Appeared as military rations.

Canned rice had already been produced before World War II. During World War II, it was mainly supplied to the army and the output was large.

▲Canned rice is still sold today

However, cooked rice will have a "regeneration" problem if it is stored for a long time, and canned rice is no exception, so it doesn't taste that delicious. People are happy. Of course, it's much better now.

As a result, in the 1940s, the American General Foods Company took the lead in producing dehydrated rice, which could be restored to steaming rice by just adding hot water.

This invention was also brought to the battlefield of World War II. And today, the self-heating rice we eat is basically improved on the basis of dehydrated rice.

After World War II, Americans who did not usually eat rice lost the motivation to continue research. Instead, the Japanese started the next step of the "rice revolution."

▲After all, for East Asians, rice is one of the traditional staple foods

In the 1950s and 1960s, with the development of Japan’s economy, the employment rate of women increased. With the increase in the number of people and single people, a quick meal became an urgent need in Japanese society at that time.

So during this period, Japan invented and improved many instant dishes, such as instant noodles and curry cubes.

The research and development of instant rice is obviously much more difficult. It was not until the 1970s that retort bag rice, aseptic packaged rice and frozen/refrigerated rice appeared in Japan.

▲Soft canned packaging is very common, such as curry

Steamed rice in bags is also called soft canned rice. It puts the cooked rice into a bag that can be heated by water. Just heat it over water when eating.

The self-heating rice in the rations of the Chinese People's Liberation Army is actually a kind of soft canned rice. Because of the need for vacuuming, the rice is squeezed into a lump, which affects the taste. It is also called "Zongzi Rice". However, in recent years, the taste has improved a lot.

Aseptic packaged rice is similar to soft canned rice, except that it is made and packaged in a sterile room.

Frozen/refrigerated rice is a prepared meal that is quickly frozen/refrigerated and then heated in a microwave oven before eating. The most representative one is the bento in a convenience store.

02 The rice in self-heating rice is not real original rice

In the past half year, the self-heating rice that has become popular online and offline is actually dehydrated rice that was born before World War II. Evolved version.

The reason why self-heating rice cooks quickly is because the rice has been processed a lot before you get it.

First of all, the raw rice needs to be washed, soaked, and gelatinized (that is, cooked). Some processes will also crush the rice and then "gelatinize" it.

The cooked rice needs to undergo the most critical step - drying. Regardless of whether it is hot air drying or freeze drying, the purpose is to quickly dehydrate fresh rice and reduce the moisture content to less than 10%.

Because the water content is low, it can be stored for a long time at room temperature.

At the same time, the molecular structure of starch in rice is also undergoing qualitative changes, from the "β state" which is not easy to absorb water, to the "α state" which is easy to absorb water, so it is also called "α" Rice." This is why instant rice can absorb water and "recover".

▲Picture/Ikuhiro Nonaka

Some processes will also expand the rice on the basis of "alpha-ized rice", so that the rice tastes better after recovery.

Speaking of recovery, now we are all accustomed to the heating pack in the lunch box, pour water and cover it, and it only takes 15 minutes.

But in an era when the cost and safety of heating packs were not as good as they are now, you really had to use hot water to restore dehydrated rice yourself.

▲Instant rice produced by Nintendo

In 1961, at a time when the rice cooker had not yet been invented, Nintendo (yes, the Nintendo that makes games) invented it Just like instant noodles, you can make instant rice by adding boiling water in 3 minutes.

Unfortunately, the manufacturing process of dehydrated rice back then was not as mature as it is now. In addition, not everyone can control the amount of water and temperature so accurately. Most of the washed rice became a bowl of porridge. The Japanese I can’t get used to it either, so I failed.

Until the beginning of this century, instant rice manufacturers held rice brewing competitions within the company to compete with who could control the amount of water and time best. At that time, self-heating instant rice was actually called Not entirely convenient.

03 Is the processed self-heating rice nutritious and healthy?

The processed dehydrated rice is indeed much more convenient to heat. But compared with ordinary rice, you will find that the taste and aroma of self-heating rice have declined.

Let’s talk about the texture first. Anyone who has eaten self-heating rice knows that it is not as elastic as ordinary rice. The rice grains are smaller and soft.

In order to restore the original taste of rice, many manufacturers, in addition to improving the process, will also add konjac and other auxiliary ingredients to improve the taste and increase elasticity.

In addition to taste, there is also a loss of nutrients.

The nutrition of rice itself is relatively simple. After soaking and heating in advance, the nutrition is further reduced, especially the B vitamins that are easily soluble in water and are not heat-resistant will lose a lot.

Furthermore, alpha-treated rice is digested faster than ordinary rice and has a more obvious blood sugar-raising effect, which is not a good thing for people who need to control blood sugar.

What cannot be ignored is the side dishes in the self-heating rice. They have been deeply processed, and the nutritional loss is not small. Generally speaking, they are dishes with a strong taste, and the oil and salt are easy to exceed the standards.

So, self-heating rice is okay as a temporary emergency food, but if you eat it for a long time, it is not a good choice in terms of taste and nutrition.

In fact, when writing this article, I also consulted a lot of papers and information.

In the 1980s, there were papers introducing Japanese instant rice; by the first decade of this century, there were also papers predicting that instant rice would surpass instant noodles.

However, it was not until the past two years that instant rice gained some momentum due to self-heating rice. Because compared to the refrigerated lunch boxes in convenience stores, self-heating rice can be stored at room temperature and can also be transported by express delivery over long distances.

Some people say that China will be like Japan, where many people live on instant rice? I don’t think it will happen in a short time.

Self-heating rice loses a lot of taste; refrigerated lunch boxes are limited by time and space; in addition, labor costs in China are not that high, and roadside restaurants are often very competitive in terms of price.

As for the future, perhaps labor costs are getting higher and higher, and when many restaurants have to use machines to replace labor, instant rice will have to become our choice.