Mirin

Mirin is a sweet rice wine with an alcohol content of approximately 14% by volume, used in Japanese cuisine both as a seasoning and as a beverage. Unlike other cooking alcohols, it has a comparatively high proportion of dissolved extractives and appears at room temperature as a brownish, sweet liquid. Its characteristic sweetness is produced through the use of kōji (麹), a mold responsible for fermentation that breaks down the starch of steamed mochigome (もち米) into maltose and glucose. Since alcohol is already added during the maturation process, little further fermentation by yeast occurs, meaning the existing sugars are not consumed and give mirin its distinctive flavor.

In the production process, mochigome is steamed and mixed with kōji before shōchū (焼酎) or a comparable alcoholic base is added to this mixture. After a maturation period of approximately 60 days, the product is pressed and filtered, yielding a light to dark brownish, distinctly sweet rice wine. During maturation, proteolytic enzymes also convert some of the proteins into amino acids and organic acids, lending mirin additional flavor nuances. The byproduct generated during production, known as mirinkasu (味醂粕) or kobore ume (こぼれ梅), is partly processed into desserts, sauces, and marinades due to its high content of sugar, protein, and dietary fiber, but is also used as animal feed or pickling material.

Traditionally, a distinction is made between hon mirin (本みりん) and variants such as mirin-fū chōmiryō (みりん風調味料). Hon mirin refers to the classically produced rice wine with approximately 14% alcohol and a high sugar content. Mirin-fū chōmiryō, on the other hand, is a seasoning that contains less than 1% alcohol and is not subject to Japanese alcohol taxation, but includes other additives such as umami components or types of sugar to imitate the flavor of genuine mirin. Another related product is shio mirin (加塩みりん), which, through the addition of table salt, is no longer classified as a consumable alcoholic beverage and therefore does not fall under the strict regulations of Japanese alcohol law.

Historically, mirin originally served as a sweet rice wine that was consumed alongside sake during the Edo period (17th to 19th century). It later gained importance primarily as a cooking ingredient, as it reduces fishy odors and imparts a delicate sweetness as well as a glossy appearance to dishes. To this day, mirin is occasionally still used as a beverage, for example in cocktails or as a base for other mixed products such as báijiǔ (白酒) or toso (屠蘇), a New Year's specialty.