The sprouts are crunchy and firm, with greenish-yellow heads.
They are ready to use in 3 to 4 days after the bean begins to sprout. They become bitter if allowed to grow much past that.
To be clear, most bean sprouts sold are actually grown from mung beans, not soybeans.
Discard any roots and bean skin that might still be present. Wash, cook for at last 10 minutes.
Some small amount of toxins (trypsin inhibitors) are present in Soybean Sprouts that are destroyed after cooking for at least 5 minutes. While not dangerous if you eat them raw only occasionally, nutritionists advise proper cooking to get rid of them.
Lower protein content than actual soybeans, but very high in vitamin C.
Soybean Sprouts were first touted publicly in the West by a Dr Clive M. McKay, Professor of Nutrition at Cornell University, during the Second World War for their nutrition and ease of production.