Does Mirin Go Bad

In this brief article, we will answer the question “does mirin go bad?” and will guide you about the uses of Mirin, its longevity, and how to ensure that it is safely stored and fit for consumption

Does Mirin Go Bad?

Not necessarily; refrigerated Mirin has an indefinite shelf life. This is because its ingredients aren’t likely to make you sick even if stored for a long time.

But its quality will start to decline slightly after two months. So it’s best to store Mirin in its original bottle and keep the cap tightly sealed.

However, if you suspect any changes in the taste, texture, or color of the sauce, it’s better to discard it and buy a new one.

How Long Does Mirin Last?

Mirin is a fermented sweetened rice beverage. Fermented alcoholic beverages are generally recognized as microbiologically safe due to their high ethanol content (4%) and low pH (<4.5). However, they may also be potentially hazardous because (i) the raw materials containing abundant sugars and starches are nutrients for bacteria; (ii) the manufacturing processes is complex, with many potential routes of contamination; and (iii) the fermentation temperature (generally 18 to 35°C for 2 to 14 days) is favorable for bacterial growth (both for the starter cultures and for spoilage and pathogenic bacteria) (1).

A sealed bottle of Mirin – stored properly in a cool, dark place safe from moisture – can last for months and even years. Usually, mirins used for special cuisines are fermented for several years to develop flavor. A study compared for up to 13 years ripen mirin with non-ripen mirins and showed that the percentage of specific amino acids in mirins matured for seven years or more was higher than in non-ripened mirins (2).   However, an open bottle will last a few weeks to some months even if refrigerated, after which its quality and flavor start to fall.

Always refer to the best-before or best-by date mentioned on the bottle. 

What is Mirin Used For?

Mirin is sweetened rice wine. It has a light syrup-like texture and is routinely used in Japanese cooking to add mild sweetness to a dish or sauce. Sweet rice wines (mirins) are alcoholic condiments high in glucose that are used as a seasoning in Japanese cuisine, and those matured for longer periods are considered to be key ingredients for top-level cuisine. Mirin is produced from glutinous rice, koji malt (non-glutinous rice malted using Aspergillus oryzae), and distilled spirit, and is saccharified at room temperature for around two months (conversion of starch into glucose). After filtration, some mirins are immediately made into seasoning products (usually by adding liquid sugar), whereas others are stored at room temperature for long periods to ripen in the presence of high concentrations of alcohol and glucose, thereby developing a well-balanced sweet flavor (2).

Mirin is a particularly good combination with grilled foods. This is because the alcohol burns while cooking, resulting in a sweet taste. 

Mirin is among the main ingredients of sweet Teriyaki Sauce which is often braised on chicken, beef, salmon, and vegetables. It is also a delicious addition to the marinade for Japanese Salad with Shiso Leaves, Korean Beef Chuck Roast, Soba Noodles, and Sake, and is also a key constituent of the sauce for Vegan Sushi.

What Is The Best Mirin?

The best type of Mirin is ‘hon-mirin’, which means true mirin. This type of rice wine is inherently sweet due to fermentation and features an alcohol content of  14 percent. 

Hon-mirin contains only three ingredients: shochu (Japanese distilled alcohol), rice, and koji, and it is almost impossible to find this variety in the United States even if the bottle states hon-mirin.

Should Mirin Be Refrigerated After Opening?

It is recommended that Mirin be refrigerated after opening to preserve its quality and flavor for longer and enhance its shelf life.

However, as long as Mirin is kept in a cool, dark place protected from sunlight and moisture, it can be adequately stored out of the refrigerator as well. These include pantries, drawers, and cupboards if they aren’t hot or damp. However, a study detected bacterial growth and physicochemical changes in Korean rice wine stored at 20°C after 3 days. No significant changes were detected in the rice wine stored at 4°C (fridge temperature) after 30 days. Therefore, it is recommended to store opened bottles of mirin in the refrigerator (3).

What Should Be The Color and Consistency of Good Mirin?

Ideally, Mirin is lightly golden and amber in color with a slightly thick and syrupy consistency. This confirms that the sauce is preserved well.

Regardless of how Mirin is stored, the ingredients in Mirin tend to separate when stored for a long time. This might cause some color variation, but once shaken, the original amber color will be evenly distributed and restored. 

Another important aspect is that the sauce might develop some whitening if you refrigerate it, especially after two months. Again, this is normal and is just crystallized sugar accumulated at the bottom of the bottle, and will go away after shaking. Changes in color and increase in turbidity indicate changes in the bioactive compounds present in the wine-type beverages. Loss on phenolic compounds, tannins and antioxidant activity and pH changes occur during long storage (4).  

How Do You Know If Mirin Has Gone Bad?

The truth is that Mirin is among those condiments that don’t generally show any signs that it has gone bad.

There are three main things to watch for when checking if Mirin has gone bad: color changes, pungent or different smell, or an off-taste. Bottle bloating indicates gas formation due to microbial activity (1).

But before anything, always inspect the sauce and bottle closely before proceeding to inspect the other aspects. The sauce might taste and smell okay, but microbes might have begun to degrade the ingredients from within, resulting in an off appearance. 

Conclusion

In this brief article, we answered the question “does mirin go bad?” and told you about the uses of Mirin, its longevity, and how to ensure that it is safely stored and fit for consumption. 

If you have any more questions or comments please let us know.

References

  1. Jeon, Se Hui, et al. Microbiological diversity and prevalence of spoilage and pathogenic bacteria in commercial fermented alcoholic beverages (beer, fruit wine, refined rice wine, and yakju). J food protec, 2015, 78, 812-818.
  2. Inoue, Yutaka, et al. Mechanisms of D-amino acid formation during maturation of sweet rice wine (mirin). Food Sci Technol Res, 2016, 22, 679-686. 
  3. Kim, Jae Young, et al. Effects of storage temperature and time on the biogenic amine content and microflora in Korean turbid rice wine, Makgeolli. Food Chem, 2011, 128, 87-92.  
  4. Sant’Anna, Voltaire, et al. Tracking bioactive compounds with colour changes in foods–A review. Dyes Pigments, 2013, 98, 601-608.