Mirin Vs Rice Vinegar: What's The Difference?

What is mirin?

Mirin is a sweet Japanese rice wine made by fermenting steamed glutinous rice with koji (a beneficial mold) and shochu (a distilled spirit). The result is a sweet, slightly viscous liquid with about 14 percent alcohol content and pronounced sweetness from natural sugars. Three main types exist: hon-mirin (true mirin, the highest quality with traditional brewing); shio-mirin (with added salt to bypass alcohol taxes); and shin-mirin or aji-mirin (mirin-flavored seasoning, often a syrup with corn syrup or other sweeteners, no alcohol). Mirin's role in cooking is to add sweetness, depth, and glaze to dishes. It's essential in teriyaki sauce, sukiyaki, glazed fish, sushi rice (in small amounts), and many Japanese sauces. The alcohol typically cooks off during cooking, leaving the sweetness and umami behind.

What is rice vinegar?

Rice vinegar is vinegar made from fermented rice wine (or rice wine that has been further fermented to produce acetic acid). The result is a clear, mild vinegar with about 4-5 percent acidity (lower than distilled white vinegar at 5-7 percent). Rice vinegar has a smooth, slightly sweet, less harsh flavor than other vinegars. Japanese rice vinegar (genmai-su made from brown rice, or kome-su from white rice) is the standard for sushi rice and Japanese cooking. Chinese rice vinegars include red rice vinegar (sweet and slightly fruity) and black rice vinegar (Chinkiang, rich and malty). Seasoned rice vinegar contains added sugar and salt, ready for sushi rice without additional preparation. Rice vinegar is used in salad dressings, sushi rice, marinades, pickling, and dipping sauces.

How do mirin and rice vinegar compare?

Production differs: mirin is fermented rice wine (alcohol); rice vinegar is fermented rice wine that has been further fermented to vinegar. Flavor differs dramatically: mirin is sweet; rice vinegar is sour. Alcohol content differs: mirin has 14 percent; rice vinegar has none. pH differs: mirin is slightly alkaline; rice vinegar is acidic (pH 2-3). Cooking applications differ: mirin adds sweetness and depth; rice vinegar adds acidity and brightness. Both can appear in the same dish (sushi rice combines both); they serve complementary roles. Storage differs: mirin lasts 6 months after opening (refrigerated); rice vinegar lasts indefinitely. Price differs: true hon-mirin costs more than rice vinegar; aji-mirin (cheap alternative) is similar in price. Bottle sizes differ; mirin is typically smaller bottles.

Can you substitute one for the other?

Not directly due to opposite flavor profiles. To substitute mirin in a recipe (when none is available): use 1 tablespoon rice vinegar plus 1/2 teaspoon sugar per tablespoon of mirin to approximate sweetness and slight tang; for non-alcoholic substitutes, dry sherry plus sugar works, or grape juice with rice vinegar. To substitute rice vinegar (when none is available): use apple cider vinegar (similar mildness, slightly fruity) or distilled white vinegar (sharper, use less); both work in most applications. Substituting mirin for rice vinegar would add unwanted sweetness; substituting rice vinegar for mirin would add unwanted sourness. For sushi rice specifically, the combination of mirin and rice vinegar (or seasoned rice vinegar containing both) is essential and difficult to substitute well.