Asian-fusion soy butter sauce is a cooked sauce that blends butter with soy sauce. When combined, the two main ingredients produce a flavor that fits the fifth taste — umami, or savory. Food scientists put foods and beverages that do not fit in the categories of salty, sweet, bitter or sour into this taste category. Soy sauce contains large amounts of glutamate, the amino acid most commonly associated with umami. Pairing soy sauce with butter produces a hearty or meaty tasting sauce with a depth that neither ingredient has on its own.
Basic soy butter sauce simply requires that one heat the desired amount of soy sauce to a boil. One then adds chunks of butter, stirring between each addition so the butter melts into the sauce. A wire whisk commonly is used to thoroughly blend the two ingredients. After incorporating the butter, one generally removes the sauce from the heat, though one can continue cooking the sauce to reduce it and intensify the flavor, if desired.
The marriage of butter's sweetness and savory soy sauce produces a sauce with a denser texture than plain melted butter; it is an emulsion that stays mixed once cooked. Adding butter gives the soy sauce body and thickens it. Recipe variations for soy butter sauce generally incorporate additional ingredients that enhance the basic emulsion.
Spicy soy butter sauces call for the inclusion of wasabi, a fiery horseradish-like root. This addition makes the sauce hot and spicy. Ginger also is a frequent addition to soy butter sauce. This spice also is a root with a spicy flavor. Unlike wasabi, ginger does not produce a hot or mouth-burning sensation when added to sauces.
Professional chefs have developed personalized versions of soy butter sauce by drawing from Western and Eastern culinary traditions. Common additions include shallots and green onions. Miso, a fermented soy paste, also appears in some recipes. A variety of hot seasonings such as pungent Chinese mustard, dried red pepper flakes and fresh local peppers have found a place in soy butter sauce recipes. Sherry, wine, brown sugar and honey also might appear in modified versions of this sauce.
Depending on the recipe used, one can use soy butter sauce as an ingredient in the dish, as a condiment added after cooking or as a dipping sauce. A number of foods are natural possibilities for the use of soy butter sauce. These range from pasta and tofu to steaks, fish, grilled vegetables and classic Asian stir-fry dishes.