Making Mirin
What is Mirin made from? This section introduces the raw ingredients, production process, and distinct characteristics of Mirin.
We’ll explore how Mirin is produced to bring a refined sweetness and rich depth of flavor to your cooking.
Roles of Raw Materials
Mirin is made from three basic ingredients,
and each has their own respective role.
Glutinous
Rice
and Rice
The main components of rice are starch and protein. These are turned into rich and sweet sugar as well as amino acids of umami by the action of koji mold. Glutinous rice containing amylopectin, starch that is easily broken down into sugar, was used. Thanks to the advances of production technology, non-glutinous rice also is starting to be used, allowing for more ingredient options.
Malted Rice
Malted rice is made by planting and growing koji mold on steamed non-glutinous rice.
The enzymes in koji mold break down glutinous and non-glutinous rice and draw out sweetness and umami. In addition to mirin, malted rice is used to make miso and sake.
Shochu,
Distilled Spirits
(Alcohol)
Alcohol has an antiseptic effect, which prevents moromi, the base for mirin, from spoiling. In the past, shochu was used as the alcohol source. Even today, producers who adhere to traditional methods use shochu to make “koshiki ‘(traditional) mirin”.
However, as shochu leaves behind a distinct aroma during cooking, it is not suitable for some dishes. The brewed alcohol used at Nagareyama Kikkoman Company (NKC) has a refreshing aroma, and the resulting mirin has a mild taste that draws out the natural flavor and aroma of ingredients to go well with any dish.
Making Mirin
Producing delicious Mirin involves a complex process.
Moromi Preparation (Shikomi)
Moromi, the base for mirin, is prepared by adding malted rice and shochu or brewed alcohol to steamed glutinous rice and rice. Yeast ferments sugar (sweetness) generated by the breaking down of starch and converts it into alcohol. To retain the sugar needed for mirin, alcohol needs to be added at this stage to stop fermentation by yeast, and draw out sweetness. In addition to the activity of yeast, alcohol also prevents proliferation of mold and other bacteria.
Saccharification and Aging
Moromi is slowly saccharified and aged in tanks for one to two months. Enzymes in malted rice generate saccharides, such as glucose and oligosaccharides, from the starch in glutinous rice and amino acids from the proteins. The sweetness and umami extracted during this process combine to impart deep and rich flavor to aged mirin.
Immediately
after preparation
After one to
two months of aging
After
pressing
* These photos show how moromi changes over time in a laboratory. This is not actual moromi.
Pressing, Heating, and Filtering
Mirin liquid concentrate, which is extracted using presses from adequately saccharified and aged moromi, is heated to halt the activity of enzymes. The resulting liquid is then carefully filtered to remove unbroken starch and protein residues to become beautifully clear mirin.
