How to store dal so it keeps its quality

Most dal that goes bad is not bad dal. It left the mill dry, clean and sound, and then spent weeks somewhere damp, warm or badly stacked. Storage decides more about what reaches the pot than most people give it credit for.

The three things that spoil dal

• Moisture. The big one. Damp dal clumps, smells musty and invites mould. Pulses keep well when they stay as dry as they left the mill, and every bit of dampness they pick up afterwards works against you.
• Heat. Warmth speeds up everything else. Insects breed faster, and moisture moves around inside a stack and condenses in the coolest spots.
• Insects. The pulse beetle is the classic pest of whole pulses. Split dal is less attractive to it, but it is not immune to storage insects in general — and an infestation that starts in one bag rarely stays there.

Get moisture right and the other two become far easier to manage.

In a godown or warehouse

• Never on the floor. Stack bags on pallets or wooden dunnage. A bare floor draws damp up into the bottom layer quickly.
• Never against the wall. Leave a gap between the stack and the wall so air can move and you can walk round it to inspect.
• First in, first out. Mark each lot with its arrival date and move the oldest first. The dal that sits at the back of a stack for a season is the dal that goes wrong.
• Keep it away from smells. Pulses absorb odour. Do not store them beside fertiliser, pesticide, diesel, onions or anything else with a strong smell.
• Respect the monsoon. Humidity climbs sharply from June. Check stacks more often through those months and keep doors closed on humid days.
• Inspect regularly. Walk the stacks every couple of weeks. Look for webbing, powder at the base of bags, clumping and a musty smell. Catching one bad bag early saves the rest.

On a shop shelf

• Keep sealed packs out of direct sunlight. A sunny window heats a pack enough to cause condensation inside it.
• Rotate stock so older packs sell first, and check best-before dates when you restock rather than when a customer complains.
• Keep loose dal in covered bins rather than open sacks, and use a clean, dry scoop.

At home

• Use an airtight container. Glass or food-grade plastic with a tight lid. Once a pack is opened, move the dal into it rather than folding the bag over.
• Use a dry spoon. A wet spoon puts moisture straight into the jar.
• Buy what you will use. A month or two of dal at a time keeps better than a year's supply at the back of a cupboard.
• Do not refrigerate it. Taking a jar in and out of the fridge causes condensation — exactly what you are trying to avoid. A cool, dry cupboard is better.
• Traditional helpers. Many households add a few dried red chillies, bay leaves or neem leaves to the jar. They are no substitute for keeping the dal dry, but they do no harm.

How to tell dal has gone off

A musty or sour smell, clumps that do not break apart, fine webbing, small holes in the grain, or a layer of powder at the bottom of the container. Any one of these is a reason to stop using that batch. Washing does not rescue dal that has taken on moisture or been infested.

The practical summary

Keep it dry, keep it cool, keep it off the floor and away from smells, and use the oldest first. Follow the best-before date on the pack — and remember that the date assumes the dal has been stored properly. Kept badly, dal can go wrong well before it.