Garlic soy sauce is an Asian-style liquid seasoning that is flavored at least in part with garlic. There are two main ways of making garlic soy sauce. Garlic cloves can either be infused and fermented with the soybeans that make up the base of the sauce, or minced and added into a finished product. Fermented garlic sauces are more rare, and are generally only available commercially. Infused versions, on the other hand, tend to be much easier and can be made at home with any standard soy sauce variety.
Soy sauce is a very common seasoning in a range of Asian foods. The first sauces were made in China centuries ago, but have since been adopted and adapted by chefs all over the world. A traditional soy sauce is made with soybeans fermented in water with specialized molds, salts, and very often grains like wheat. Garlic varieties incorporate garlic cloves or flavoring in some fashion, whether at fermentation or later as an infusion. Garlic is a common ingredient in many of the dishes that soy sauce is traditionally used with, which makes the flavor combination a natural one.
The most complicated way to make garlic soy sauce requires control over the entire production process. Garlic cloves can be added in with the soybeans as they ferment or with the wheat that is added to thicken the brew. Under this method, the garlic actually contributes to the character of the soy sauce batch. Sometimes the final product tastes of garlic, but not always. Garlic that has been fermented often has a very distinctive taste.
Fermented garlic soy sauces are typically made in small batches, often for home use or small-scale distribution. A garlic soy sauce made in this fashion often carries a very pungent smell and is usually used sparingly. Flavored brews are popular in some places, but standard soy varieties are far and away the most popular commercially.
The most common garlic soy sauces are little more than infusions. They begin with standard soy sauce that cooks and manufacturers augment with garlic cloves or minced pieces. Commercial versions often include garlic particles in the bottle, which is usually visible as a sort of sediment on the bottom that incorporates when shaken. Making garlic soy sauce at home is often as simple as soaking chopped pieces in purchased sauce. In most cases, the longer the garlic is infused in the sauce, the stronger its flavor will be.
Garlic and basic soy sauce are the only required ingredients, but more complex iterations may also include thickening agents like brown sugar, oil to help the flavors emulsify, or other flavoring agents like citrus zest or black pepper. Cooks can control the final taste of their blends by experimenting with the amount of garlic used, the total soak time, and any additional ingredients. Garlic soy sauce is a very common marinade for meats and vegetables, but can also be used as a more general sauce for rice and stir-fry dishes.