More than 2500 soybean varieties have been identified worldwide.
Soybeans are a legume and can be broadly classified as “vegetable” (food) or “field” (oil) types. Vegetable-type soybeans are selected based on ease of cooking, a mild and nutty flavor, texture, protein composition, and sweetness.
Soybeans come in different colors, sizes, and can vary in their nutritional profiles.
Size: Soybeans can range in size from a mustard seed to the largest edamame varieties.
Color: Soybean varieties include a range of colors including white, yellow, green, red, brown, black, and speckled types.
Another distinguishing characteristic between soybean varieties is the hilum color or the scar on a seed marking the point of attachment to its seed vessel. This color can be white, yellow, clear, buff, brown, or black.
Protein Level Range: A review of the USB Specialty U.S. Soy Database revealed that 2021 food grade soybean varieties ranged from 36.385 – 48.015 in protein levels.
See for yourself https://soydatabase.ussoy.org/
The most common soybean colors include:
Yellow Soybeans. Yellow soybeans are familiar to most people. Yellow soybeans are traditionally used for making soymilk and tofu. The smallest varieties are used for fermentables (Natto & Tempe) and the medium to large varieties (with a clear hilum) are most often used for making soy milk. Yellow soybeans with a dark hilum look and taste like black eyed peas, with a more robust nutritional profile. Yellow soybeans cook up beautifully for vegetable sides or as center-of-the-plate entrees. Yellow soybeans make an outstanding high-protein hummus. While edamame is harvested green, they are not green soybeans. When mature, edamame seeds are yellow.
Black Soybeans. Black soybeans are very versatile and are easy to incorporate into several American dishes. They have a milder flavor than yellow soybeans and can be substituted for any dish that calls for black beans. Black soybeans make a savory hummus and are a nutritious addition to all kinds of bean dips and soups.
Green Soybeans. Green soybeans have been most widely used to manufacture soy flour (kinako) or to make traditional simmered soybeans. They make an interesting hummus as well and are a great addition to soups.
Green beans and black soybeans stand alone as the lowest carb beans, with high-protein and fiber as well.