One of the most important condiments in Japanese cooking, Mirin (sweet cooking rice wine) is a sweet and syrupy liquid that is used as a seasoning and glazing agent.  It is a type of rice wine similar to sake, but with a lower alcohol content (14% instead of 20%).
 
Hon mirin (本みりん) contains 14% alcohol and 0% salt.  Steamed glutinous rice, rice koji mold, and shochu (distilled alcoholic beverage) are mixed and fermented for about 40 to 60 days.
 
Enzymes in rice koji decompose starch and proteins of glutinous rice and various saccharides, amino acids, organic acids, and fragrance ingredients are produced to form Mirin.
 
Hon mirin has more alcohol; therefore, you can store it in a cool place up to 3 months.
 
If you store it in the refrigerator, sugar may crystalize.