The traditional method of making steamed soybeans wrapped in straw, straw soaked in boiling water at 100 degrees Celsius in order to sterilize, and kept at 40 degrees Celsius for a day, the common Bacillus subtilis (natto bacteria) on the straw due to the production of spores and high heat resistance, the sterilization process is not damaged, high temperature cultivation speed can also inhibit the other strains of bacteria, and the fermentation of soybeans to produce a viscous filamentous matter, which is sticky! Appearance

Mainly from the glutamic acid in the ingredients, which is considered to be the source of Natto's delicious flavor.

In the late twentieth century, high-quality straw was hard to come by, and it was often sold in Styrofoam or paper containers. Therefore, the modern way of making natto is to use steamed soybeans mixed with artificially cultivated natto mushrooms and put them directly in a container to ferment them, and some foods other than soybeans can also be made into natto.

In the case of sake, if the rice used to make the sake is contaminated with the natto bacteria, the rapid growth of the bacteria will inhibit the yeast needed to make the sake. Natto must not be present in the sake brewing premises, but other fermented foods may be similarly affected, so the process requires careful attention.

Natto bacteria are weakly acidic, and can hinder the production of lactic acid by lactobacilli. Technically, weaker-smelling natto has been developed.

However, the use of natto strains with low viability can create room for other bacteria to proliferate. In addition, the natural enemy of the natto bacteria is the phage virus that parasitizes the bacteria. When the phage begins to act, it reduces the activity of the natto bacteria and may cause other bacteria to begin to multiply, so you should avoid consuming natto that has exceeded its shelf life.

Natto bacteria are weakly acidic and can block the lactic acid produced by lactobacilli. Natto with a weaker odor has been technically developed, but the use of natto strains with lower viability can easily create room for other bacteria to proliferate. In addition, the natural enemy of natto is the phage virus that parasitizes the bacteria, and when the phage begins to act, it reduces the activity of the natto bacteria and may cause other bacteria to begin to multiply, so you should avoid consuming natto that has exceeded its shelf life