When something in your fridge or pantry goes moldy, you know you have to throw it away or compost it. However, there’s a Japanese ingredient called koji, scientifically known as aspergillus oryzae, and it’s a type of fungus that can make any food turn into something delicious. Although it’s mold, it won’t make you sick because it’s evolved to be completely edible. If you’ve ever had miso, sake, or even soy sauce, you’ve already tasted koji, so you know you’ll be ok to use it in your own kitchen.
You can make your own koji at home, but it’s generally better to buy it pre-made. You can find it online or in Asian stores, and it looks kind of like grains since it is rice that’s been inoculated with the mold. The easiest way to use koji in your kitchen is to grind it up in a blender or spice grinder into a powder to sprinkle over your food.
Koji is alive, so it can help basically ferment foods in a short period of time. Sprinkle it on beef to get a dry-aged taste and texture by just sitting in it for a couple of days in the fridge. Whatever you put it on, the flavor will be so elevated you’ll start to put it on everything!