What the name covers
Mung beans (lv dou; also written lu dou), green gram and Vigna radiata refer to the food plant identified by NParks. The mature seeds are green and smooth. This page covers ordinary dry food seeds, not a supplement, germination kit or personalized food therapy.
Taste and texture
NParks describes green, smooth mature seeds. When making whole-bean soup, the useful endpoint is a soft centre; the Singapore recipe cooks until soft. Whole green beans, hulled split dal, sprouts and isolated starch are different food forms.
What to buy
Look for mung bean / green gram / Vigna radiata on a food label. Choose intact, dry beans with a current best-before date and little broken material, following CSU’s dry-bean shopping advice. Do not confuse Vigna radiata with black gram or an unidentified “green bean” vegetable.
Cleaning before cooking
Spread out the dry beans to remove stones, plant debris and damaged beans, then rinse in clean water. Sorting is needed even for a packaged agricultural food; it is not a guarantee of zero contamination.
Soaking: when it is needed
A presoak is not used in the cited Singapore recipe. If you choose to soak whole beans to shorten cooking, CSU treats it as optional: drain, rinse and cook in fresh water. Keep long soaks refrigerated; do not assume sprouting directions are cooking directions.
A concrete kitchen method
A concrete source example uses 300 g (10.6 oz) whole mung beans with 1.5 L (about 6¼ US cups) water. Bring to a vigorous boil, then reduce heat and cook about another 20 minutes or until soft. The printed recipe describes about 10 minutes before the vigorous boil; stove power and bean age vary, so softness is the endpoint. This is the bean-preparation stage of a stew, not a medicinal dose.
Keeping dry, fresh and cooked forms
Keep uncooked beans sealed in a cool, dark, dry place, as CSU recommends. After cooking, use shallow portions and refrigerate within two hours at 4°C (40°F) or below; use within three days. A packet of sprouts needs separate cold-chain and cooking guidance, not the dry-bean rule.
Whole beans and a processed bean ingredient
For a pot of mung-bean soup, first check that the packet contains the food beans the recipe expects. A starch or a prepared dessert mix is not the same purchase as whole dry beans, even when the name on the front includes mung bean. Read the ingredient form before borrowing the whole-bean sorting, soaking and simmering steps.
An ordinary kitchen sequence is to inspect and sort the dry beans, rinse, follow the chosen food recipe, and check tenderness rather than only the clock. CSU explains why sorting comes before the pot: beans are an agricultural product and may contain small stones or plant debris. Rinsing removes dust but does not replace that inspection. If the pot is taking longer than expected, check that liquid still covers the beans and continue checking the centre; the broad dry-bean time range is not a promise for every packet.
Cold is a traditional category
The cited Hong Kong publication describes mung beans as sweet and cold. This does not mean the soup must be cold to eat. It is not a calorie label, a measured body-temperature effect or a diagnosis. Different source claims should remain separately attributed.
Evidence boundary
The sources here establish botanical identity, food handling and a traditional classification, not a treatment effect for mung-bean soup. Food composition and extracted compounds do not establish clinical benefit from an ordinary serving. The NParks page includes medical wording that we have not adopted. Sprouts are a separate food form and need their own food-safety guidance.
The dry-bean extension page supports sorting, moisture protection and a tenderness check. It does not test traditional “cooling” claims or concentrated mung-bean preparations. Even a well-described cooking method answers how to prepare food; it does not turn the resulting soup into evidence of a treatment effect.
Cooked-food safety: a separate clock
For cooked soup, porridge or beans, divide leftovers into shallow containers and refrigerate within two hours at 4°C (40°F) or below. Use within three days; reheat thoroughly once. This is general cooked-food guidance, not the shelf life of the dry packet.