Amazing Koji Mold World: 41
Story Of Vinegar – Part 2

Written and illustrated by Misa Ono

The most popular vinegar in Japan is rice vinegar, though there are many other kinds. One of them is black vinegar. It is made in a pottery in Kagoshima, southwest of Japan.

no-41_story_of_vinegar-2In a 60cm-tall pottery, place steamed brown rice, brown rice koji and water. Cover it with another layer of the brown rice koji to protect it from bacteria outside. The koji changes the steamed brown rice to sugar, and the yeast produces alcohol. Once it is fermented with alcohol, unwanted bacteria stay away from it, and the acetic acids start to ferment it.

The more brown rice is used, the more amino acids and glucose are produced. In the warm climate of Kagoshima, the sunlight heats the glucose of the amino acids turning it to brown (Maillard reaction*). The longer it is rested, the darker and smoother the color and taste become. As black vinegar has its distinctive flavor and mild sourness, it’s easier to have than other vinegars. Besides, the brown rice is more nutritious including minerals than white rice, so many health-conscious people choose and drink it.

Another kind of vinegar is called “kasu vinegar (or red vinegar)” which is made of sakekasu (sake lees), and often used in sushi restaurants. Sakekasu turns brown after aging for 2 to 3 years. After mixing it with water and leaving it for 10 days, the yeast and other bacteria in sakekasu increase the alcohol amount and its sourness. Filter it and let it age for 3 to 6 months to a completed kasu vinegar. It goes well with sushi rice so sushi made with kasu vinegar was very popular in Edo period.

Moromi vinegar” is another type of vinegar that is made by filtering moromi lees after distilling Awamori (Okinawa’s shochu). To make Awamori, it requires black koji mold which produces a lot of citric acids for anti-bacteria reason. So moromi vinegar has a distinct sourness of the citric acid, and is rich in amino acids. This vinegar was originally for cattle like pig. But people found that the pigs fed with this vinegar hardly got sick and the quality of their meats were better than others. It’s good for pigs, so why not for human?  That’s the start of moromi vinegar going into the market for people.  The citric acids help the recovery from fatigue as well as improve the intestinal environment restraining harmful bacteria.

“Plum vinegar” is water that comes out in the process of pickling plums in a lot of salt.  (This may be closer to soy sauce rather than vinegar.) The pickled plums called umeboshi and the water are very salty and sour.  The water is usually added with red shiso leaves which colors it beautiful red. When you pickle vegetables or cook something with the vinegar, the dishes become nicely red and flavored. Also the sourness improves your appetite. It’s making my mouth watery now!

Other than these vinegars mentioned, there are still many kinds of vinegar in Japan such as apple, grapes and some other citrus fruit vinegar. Adding a little amount of vinegar enhances the taste of meals a lot. Good to try it!

(*) Browning reaction. The same reaction as browning soy sauce or miso as they age.