Rinse about 1/4 cup beans, peas or seeds (such as alfalfa or barley) or 2 tablespoons small seeds or 1/2 cup lentils thoroughly in a strainer.
Place the rinsed beans or seeds in a clean quart-size jar. Cover the opening with cheesecloth or a clean nylon stocking and secure with a string, rubber band or metal canning jar ring. Keep the cover on through the sprouting process. Fill the jar with lukewarm water, and let it soak at room temperature overnight.
The next day, pour off the water, then rinse and drain again.
Place the jar, tilted, in a warm, dark place. This lets moisture out and oxygen in. In about 3 to 5 days, the beans or weeds will sprout.
When the sprouts reach the length of their original bean, pea or seed, place the jar in a sunny spot so the sprouts will turn green.
Rinse the sprouts and drain well before storing in the refrigerator. The sprouts will keep up to two weeks if tightly sealed in a plastic bag or jar.