This past weekend I learned how to make traditional miso paste by hand. A key ingredient in many traditional Japanese dishes, miso is a paste commonly made of fermented soybeans, rice, and salt. As a fermented food, miso is a living food, containing beneficial cultures that will strengthen your digestive system. Though I have eaten miso for all of my life, I’ve never really understood the chemistry or process of miso-making. Miso is usually combined with dashi to make miso soup. Today, miso is easier and easier to find, and is pretty much available in most mainstream health foods stores. However, it’s still quite expensive, and organic brands are still limited.
In Japan, there are as many miso types as there are varieties of vine in California. Miso can be made from other grains as well, and achieves different color and flavor profiles with different lengths of fermentation and soybean preparations. Like other living foods, like a sourdough starter, miso can vary from region to region even when made with the same ingredients and process.
The ratio for our miso was 1.25 lbs koji, or fermented rice, 1/2 lb salt, and 1 lb of dried soybeans.
We started with large pots of boiled soybeans that were grown at the Shumei farm last year. We strained the water, saving the liquid to incorporate back into the miso at the end. The soybeans are cooked until soft, and are easier to mash if warm.
The beans are mashed into a smooth paste. We used a meat grinder.
The koji and salt are thoroughly combined.
The koji and salt is mixed with the ground soybeans into a paste. Some cooking liquid is incorporated back into the mixture. Too much liquid will cause bacterial problems.
The paste is formed into balls and thrown forcefully into the bottom of a jar to eliminate air. All of our jars were thoroughly washed and sterilized with a strong alcoholic sake before using them.
Jars are topped with a layer of plastic, covered in salt to aid preservation. The miso paste will then ferment for 3-6 months, developing a deeper flavor and color. All air should be pushed out, to reduce bacteria. If the miso rises during fermentation, it should be pushed back down.