Everyone knows soy sauce - and the assumption is often that tamari and soy sauce are interchangeable and the same. Yes, you may be able to substitute one for the other in most recipes, but the products themselves are quite notably different. Different ingredients, taste and texture, different fermentation process and different histories... (At Totally Nuts we always use only gluten free Tamari).
Ingredients:
Soy Sauce: Contains fermented soy beans, water, salt and wheat - often a lot of wheat. The taste tends to be sharper and saltier.
Tamari: Contains fermented soy beans and water - sometimes with a little wheat. Tamari is thicker in texture, and the flavour is generally more subtle, smoother and rounder.
Fermentation process:
Soy Sauce: Wheat and soy beans are cooked together. Salt water is added to the resulting mash, called koji. The mixture is stirred, fermented and aged, then pressed to produce the soy sauce.
Tamari: Originally tamari was a byproduct of miso production ('tamari' literally means 'to accumulate'). When the soy beans are left to ripen and ferment to make miso, a liquid byproduct is expelled - known as tamari. These days to meet commercial demand, tamari is often made directly by soaking and cooking the beans, then fermenting them and leaving to age for several months.
History:
Soy Sauce: Soy sauce has been brewed for centuries in China as a seasoning base. Variations on the same principle are traditional ingredients in many Asian countries - Vietnam, Indonesia, Malaysia.
Tamari: Originated in Japan as a byproduct of miso fermentation.