Soy sauce is a richly flavorful liquid made from a fermented paste of soybeans, grain, brine and a form of Aspergillus mold. It’s the essence of umami – even a teaspoon brings a deeply savory flavor to any drink that calls for it.
If you’re not a fan of soy, there are lots of substitutes you can reach for, like Maggi sauce or Bragg’s Liquid Aminos.