Differences between light and dark soy sauce explained

Light and dark soy sauces differ primarily in their fermentation process and ingredients. According to nutrition expert Katharina Holthausen from Verbraucherzentrale Bayern, both varieties are based on fermented soybeans, salt, and water, though wheat may also be included.

Dark soy sauce typically undergoes a longer fermentation process and often contains added molasses, a byproduct of sugar production. This results in a stronger, slightly sweeter flavor profile. In contrast, light soy sauce is described as milder.

Usage recommendations suggest that light soy sauce is well-suited for seasoning meat, fish, and tofu. Dark soy sauce is better utilized in stews, braised dishes, or as a dip. Due to high sodium levels—potentially up to 17 grams of salt per 100 milliliters—experts advise using the sauce sparingly. Consumers with celiac disease should specifically look for gluten-free options.