How to sprout moong at home (step by step, with timings)

Soak, drain, keep damp, wait. Whole green moong needs three things to sprout: water to wake it (the soak), air so it does not drown (the drain and the cloth or jar), and warmth, which decides the speed: about a day in summer, two or three in winter. Rinsing twice a day keeps the beans damp and washes away the sourness that builds up in still water. You are done when the white tails are about the length of the bean, the stage when the sprouts are crunchy and mild. The ICMR-NIN dietary guidelines give the same rule: a sprout should grow only as long as the grain itself, because after that it starts to use up the nutrients stored in the grain. One cup of dry beans gives roughly 2 to 2.5 cups of sprouts, enough for four bowls of sprouts chaat.

1. Pick the beans. Use whole green moong that is bright olive green and even in size; dull, yellowed or old beans sprout slowly or not at all. Split dal and chilka moong will not sprout. Half a cup of dry beans is a good first batch.
2. Rinse. Put the beans in a strainer, rinse them well under running water and drain. Pick out any that float, are broken or look discoloured.
3. Soak overnight, 8 to 12 hours. Cover with three times their volume of clean water, so the beans stay under water as they swell, and leave at room temperature. The beans double in size and the skins turn matte. In summer the shorter end of the range is enough; if the water smells sour, change it.
4. Drain completely. Tip into a colander and leave it 10 minutes so no water pools. Wet beans rot; damp beans sprout.
5. Tie in muslin or move to a jar. For the cloth method, gather the beans loosely in a clean, damp muslin or thin cotton cloth, tie it and hang it or set it in a colander over a bowl. For a jar, use a wide-mouthed glass jar with a mesh or muslin lid, laid on its side at an angle so it drains and breathes.
6. Rinse twice a day. Morning and evening, run cool water through the cloth or jar and drain again. In summer rinse three times. Keep the bundle in a dark, airy corner of the kitchen, away from the stove and out of the fridge.
7. Harvest at one to three days. Tails show within 12 to 24 hours in summer, 24 to 36 hours in mild weather and two to three days in winter. Stop when they are roughly as long as the bean, give a final rinse, drain well and move the sprouts to the fridge in a lidded box with a paper towel under them.

All three work; they differ in how much air the beans get and how much water they hold. The tied muslin bundle is the traditional Indian method and a forgiving one, because the cloth wicks away excess water and air reaches every bean; it needs a damp cloth, not a wet one. The ICMR-NIN dietary guidelines describe the household method the same way: a moist cotton or muslin cloth that covers the grains loosely so that air can circulate, kept out of direct light. A glass jar with a mesh lid is easier to rinse and to see into, but the beans at the bottom sit in the drips, so tilt it and shake the beans into a thin layer after each rinse. A plastic sprout maker with stacked trays does the tilting for you and is worth having if you sprout every week; rinse the trays with hot water between batches, because the corners hold old sprouts. Whichever you use, the rule is the same: damp, dark, airy, rinsed twice a day.

• Too wet. Beans sitting in pooled water go slimy and smell sour within a day. Drain for a full ten minutes after each rinse, use a cloth rather than a bowl, and never cover the beans with water after the first soak.
• Too warm. In peak summer the beans can turn sour before they sprout; rinse three times a day, keep the bundle in the coolest corner, and harvest at 12 to 18 hours rather than waiting for long tails.
• Too cold. In a north Indian winter the kitchen can be too cold for anything to happen. Move the bundle to a warm spot (near, not on, the water heater, or the top of the fridge) and expect two to three days.
• Old beans that will not sprout. If the soaked beans swell but show no tails after three days in a warm spot, the batch is probably old or was heat-damaged in processing. There is no fix; cook them as dal and buy a fresher pack. A spoonful soaked overnight and tied in a damp cloth is a quick freshness test for any pack.
• Soaking too long. Beans forgotten under water for a whole day, especially in summer, turn sour and sprout poorly. Overnight is enough.
• Forgetting the rinse. One missed rinse in summer is enough for a smell to start. If the sprouts smell sour or feel slimy, throw the batch away.
• Growing them too long. Tails longer than the bean mean a softer, more watery sprout with less flavour; for chaat and sundal, short tails are the point.

The numbers below are for whole green moong at ordinary Indian room temperatures; a colder or warmer kitchen shifts the sprouting time far more than the soaking time.

Half a cup of dry beans (100 g) makes two servings of 50 g, and a full cup makes four. If you sprout a full cup at once, refrigerate it all at harvest and take out one bowl at a time. US FDA advice is that people more vulnerable to foodborne illness, which it lists as children, older adults, pregnant women and anyone with a weakened immune system, should avoid all raw or lightly cooked sprouts, including mung bean sprouts.

These are kitchen timings. The ICMR-NIN dietary guidelines, for comparison, give an overnight soak with the grains fully under water and sprouting in one to three days at warm room temperature. A laboratory has tested the question as well: a 2023 study in Frontiers in Nutrition that tuned germination for polyphenol content arrived at an 11-hour soak at 25 °C followed by three days of germination at 28 °C. That is an optimum for one measure in a laboratory, not for crunch; at home, stop when the tail is as long as the bean.

Steamed for five minutes, they go into many dishes. A classic use is sprouts chaat: the steamed sprouts are mixed with onion, tomato and cucumber, sharpened with lemon and chaat masala and topped with pomegranate and peanuts, with no oil. Tempered with mustard seeds and curry leaves and finished with coconut they become sundal, the Tamil evening snack; a handful goes into poha or upma at the end; and simmered with onion, tomato and garam masala they turn into usal. What sprouting does to the bean is on the moong sprouts benefits page, and the protein, fibre and calorie figures, which IFCT 2017 prints for the dry grain only, are under green gram protein per 100 g. For the bean itself, its names, cooking and storage, start with the green gram guide.

How to soak moong?

Rinse whole green moong well in a strainer, then cover it with three times its volume of clean water and leave it overnight, 8 to 12 hours, at room temperature. The beans double in size. Drain completely and use the beans for sprouting or cooking; discard the soaking water. In summer the shorter end of the range is enough.

How green gram sprouts: what happens inside the bean?

Water wakes the seed. The soaked bean swells, its skin loosens and it begins to draw on the food stored inside it to grow; the root, which is the white tail you see, pushes out first, within a day in warm weather. The green shoot comes later; Indian kitchens harvest at the tail stage, when the sprout is crunchy and mild.

How long do moong sprouts take?

One to three days after an overnight soak: about 12 to 24 hours in summer, 24 to 36 hours in mild weather or the monsoon, and two to three days in a cold winter kitchen. The tails are ready when they are roughly as long as the bean. Warmth speeds it up and cold slows it down; the soak stays overnight all year, at the shorter end in summer.

Why are my moong sprouts smelly or slimy?

Too much water or too much heat. Beans left sitting in pooled water, or a bundle kept near the stove in summer, ferment instead of sprouting and turn sour and slimy within a day. Drain for ten minutes after every rinse, rinse three times a day in hot weather, and keep the bundle in a cool, airy spot. A sour-smelling or slimy batch should be thrown away.

How long do moong sprouts keep in the fridge?

Not long, so sprout only what you will eat soon. Keep them in a closed container lined with kitchen paper to take up moisture; rinse and drain them well before they go in, and rinse again before eating. Throw them out if they smell sour or feel slimy. At room temperature sprouts keep growing and soon start to smell, so move them to the fridge once the tails are as long as the bean.

Can green gram sprouts be eaten raw?

Most adults can: the ICMR-NIN dietary guidelines note that sprouts can be eaten without further processing. Rinse them twice a day while they grow and once more before eating, and keep them in the fridge. The US FDA adds a caution: bacteria on a seed can multiply while it sprouts, so children, pregnant women, older people and anyone whose immunity is weak should not eat sprouts raw or lightly cooked.

Can I sprout moong dal (split) at home?

No. Split moong dal and moong chilka are broken seeds that can no longer grow, so they only swell and then ferment. Sprouting needs the whole green bean with its skin intact. If you have only dal, cook it; if you want sprouts, buy whole green moong and check that it is fresh, because old beans sprout poorly.