How to cool leftovers

Where the numbers come from, and where they do not

Cooling times, storage windows, safe temperatures and defrosting schedules are food-safety numbers rather than culinary ones. FoodHQ publishes none of them — follow current Food Standards Agency guidance. That includes how long food may be left to cool, how cold it needs to get, and how long it keeps once chilled.

What this page covers is the part nobody publishes and everybody needs: a large deep pot of hot stew cools astonishingly slowly, and there are several easy ways to make it cool many times faster.

The reason it matters is simple enough to state without any numbers. The middle of a big pot stays warm for hours, and that is the part of the food nobody can see.

What actually speeds it up

All of these work by increasing surface area or by taking heat away actively.

• Divide it. The single biggest factor. Split a large pot into several shallow containers and the cooling time collapses. Depth matters far more than volume.
• Use wide shallow containers, not deep ones. A tray beats a tub.
• Do not put the lid on until it is cold. A lid traps heat and steam. Cover loosely, or leave it off and cover once chilled.
• An ice bath. Stand the pan in a sink of cold water with ice, and stir. Stirring is what makes it work — it moves warm liquid to the cooled edges.
• Change the water as it warms, or run the cold tap slowly into the sink with the plug out.
• Ice as an ingredient, for stock — a few clean ice cubes stirred in both cool and dilute it slightly.
• Portion it now, not later. Small portions cool fast and reheat fast, and you were going to portion it anyway.

A large pot of stew, soup or stock

1. Take it off the heat and stop stirring it over the burner — you are only adding heat.
2. Decant into several shallow containers or trays straight away rather than waiting for the pot to cool.
3. Or stand the pot in a sink of cold water with the plug out and the tap running slowly, and stir it regularly.
4. Leave containers uncovered or loosely covered while they are still warm, so steam can leave.
5. Spread them out rather than stacking them. Stacked containers insulate each other.
6. Get them into the fridge according to Food Standards Agency guidance rather than waiting for them to reach room temperature.
7. Cover and label once chilled.

Why some foods are slower than they look

Thick and starchy

Stews, soups with pulses, rice dishes and porridge conduct heat badly and hold it for a very long time.

Large joints

A whole roast holds heat in the centre for hours. Carve before chilling.

Deep containers

Depth is what decides cooling speed, far more than total volume.

Fat on the surface

Insulates. A layer of fat on a stock slows cooling noticeably.

A full fridge

Cools slowly and unevenly if there is no room for air to circulate.

Rice

Handled with particular care in food-safety guidance. Follow the Food Standards Agency on it specifically.

Common questions