How to Grow Bean Sprouts
Soak the beans. Grab two handfuls of green beans (1 ounce to 1.5 ounces) and wash them clean. Soak for 10-24 hours. If you feel like it's soaking for too long and you don’t have time to take care of it, use warm water. Because the skin of these green beans is very hard, and it’s difficult for teeth to grow. After soaking in water, it’s easier for teeth to grow.
Soak for 12 hours, the bean shells crack open, and many have already sprouted. To this extent, it’s already a success.
Prepare the steamer, towel, and black cotton cloth (old clothes). Why prepare the black cotton cloth? Because the bottom of the steamer has holes, and the air can enter better. The towel will absorb water, and the beans are placed on top, providing water for the beans. The black cotton cloth is to block out light.

Moisten the towel in the pot. The towel must be moistened first, but not too much water.
Evenly spread the soaked green beans.
Cover with a moist black cotton cloth, so that the beans that grow are slender (). You must not let the black cotton cloth be exposed to light. If it’s exposed to light, it will change color and won’t grow into a slender bean sprout shape.
On the fourth day, when the bean sprouts grow taller than the pot, open the black cloth to see!
How about it? With roots and leaves, this is the normal bean sprout. This is the well-sprouted bean sprout. This method is very convenient, and you can use it as needed. If you don’t take it, it won’t spoil because the towel is moist, and it won’t dry out.
White and plump bean sprouts are ready. Wait for them to be put in the pot. When they grow to a certain height, use scissors to cut the part you need. Be sure to use it immediately.

Above is a personal opinion, for reference only. Thank you!