Although there are now ninety mirin producers in Japan, only a few use the simple ingredients sweet rice, koji, and shochu and the traditional process just described. Some manufacturers buy inexpensive molasses shochu and use koji made by automated machines, then they add sweet rice or corn starch to make a quicker, less expensive mirin, which is rarely aged more than a few months. Other mirin usually sold in Oriental foods stores are actually synthetic blends of syrup, glucose, corn syrup, ethyl alcohol, amino acids, and salt This type of mirin has no depth of flavor and can serve only as a sugar substitute in some types of cooking. There is also a related product sold in some natural food stores that is made without sweet rice and has salt added to it. Although this product is often called mirin, it is known as ajinohaha. Ajinohaha cannot be legally sold as mirin in Japan even though it is often passed-off as "mirin" in the US.
When asked how shoppers can tell if they are buying authentic mirin, Sumiya quickly replies, "It's the one you can drink." As we have seen, mirin had its beginning as a prized rice liqueur. So, if you want to toast the New Year with O-toso or add richness, balance, and luster to your cooking rather than merely a sweet taste, read labels carefully. Authentic mirin contains rice, sweet rice, and water, and it has no additives or preservatives - surprisingly simple ingredients for such a complex, delicious, and versatile food.