Can soy sauce and tamari be used interchangeably?
Soy sauce and tamari are both made by fermenting ground soybeans. Soy sauce includes some roasted, cracked wheat along with the soybeans. True tamari is wheat-free, but some modern tamari does contain wheat. To see if tamari was an acceptable stand-in for soy sauce, we tried several brands alongside soy sauce on rice and in a pork and broccoli stir-fry.
Results varied slightly from brand to brand, but most tasters found the stir-fries made with tamari to be “meatier” than the ones made with soy sauce of the same brand. When the two were drizzled on plain white rice, the results were clearer: Every taster perceived deeper flavor in the tamari than in the soy sauce, calling it more “complex” and “savory.” Some tasters also found the tamari to be saltier (the labels listed more sodium in tamari than in soy sauce), but the two sauces can be used interchangeably.
THE BOTTOM LINE : Tamari is a bit more flavorful and slightly saltier than soy sauce, and it’s a fine substitute.