Lentils, chickpeas, beans, soy and soy foods: nutrition, soaking, cooking, storage and practical uses.
Yes. Cooked beans, chickpeas and lentils can be frozen. In airtight containers at 0°F (-18°C), about 3–6 months is a practical best-quality range. Freezing in small portions with a little cooking liquid can help limit drying.
Among cooked legumes, soybeans and lupins stand out for lower total carbohydrate: about 8.4 and 9.9 g per 100 g. Lentils follow at ~20.1 g, kidney beans around ~22.8 g and chickpeas ~27.4 g. Soybeans and lupins devote more of their dry matter to protein and, for soybeans, fat.
An overnight soak is a convenient target for chickpeas and many dry beans because it gives the seed time to hydrate before cooking. Longer is not automatically better, and a bowl that will sit beyond overnight is better kept refrigerated.
Discarding soaking water can reduce some oligosaccharides associated with gas and other soluble compounds. It can also carry away minerals and nutrients. There is no single rule for every legume: fresh cooking water may help digestive tolerance, while using the soaking water can also be reasonable if you tolerate legumes well.
Canned legumes are not nutritionally inferior simply because they are canned. Once both forms are cooked, protein, fiber and carbohydrate are broadly similar. Added sodium is often the biggest difference, and draining and rinsing can reduce it substantially.
You do not have to rinse canned beans for safety. Rinsing is useful when you want less sodium or less packing-liquid flavor: one study found a 36% sodium reduction after draining and 41% after draining plus rinsing.
Foam on chickpeas, beans or lentils during cooking is normal. Proteins, saponins, starch and other soluble compounds move into the water and help stabilize bubbles. It is not dirt and does not mean the legumes are spoiled.
As a conservative guideline for cooked leftovers, lentils should be used within 3–4 days when promptly refrigerated at 40 °F (4 °C) or below. Cool large batches in shallow containers and do not leave them at room temperature for more than two hours.
Among plain cooked references, mature soybeans provide about 5.1 mg iron per 100 g, white beans 3.7 mg, lentils 3.3 mg and kidney beans and chickpeas around 2.9 mg. This is nonheme iron, so absorption depends on the rest of the meal.
Cooked chickpeas fit the same conservative leftover rule as other cooked foods: 3–4 days at 40 °F (4 °C) or below when refrigerated within about two hours. Once opened, canned chickpeas also need refrigeration.
Legumes contain fermentable carbohydrates such as raffinose, stachyose and verbascose. Some reach the colon and are fermented by gut microbes. Soaking, discarding the water, cooking thoroughly and increasing portions gradually can reduce discomfort.
Among common cooked legumes, green peas are about 84 calories per 100 g, lentils about 116, and many beans about 125–135. Chickpeas and mature soybeans are more energy-dense but also bring different nutrient profiles.