Tamari (Best Option)
1 tablespoon per 1 tablespoon soy sauceTamari is a gluten-free soy sauce alternative made from fermented soybeans, offering a very similar flavor profile to traditional soy sauce. Its balanced saltiness and umami contribute to the depth of flavor in quick breads without altering moisture content.
When using tamari, measure it 1:1 with soy sauce to maintain consistent salt levels. Because tamari is slightly less salty than some soy sauces, you may want to taste the batter and adjust salt accordingly.
The final quick bread will have a comparable savory depth and color to one made with soy sauce, preserving the intended flavor complexity without affecting texture.