What does the shallow vs deep cooling experiment test?

It tests one variable: depth of the container. The idea is that hot soup spread in a shallow dish cools much faster than the same amount in a deep bowl.

40-minute experiment

Shallow vs deep cooling

Why we cool food in shallow trays.

The idea

Hot soup spread in a shallow dish cools much faster than the same amount in a deep bowl.

The one thing you change: Depth of the container

You need

2 cups of hot water, or soup you won't eat afterwards
A shallow dish
A deep narrow bowl
A thermometer
A timer

Steps

Pour equal hot amounts into the shallow dish and the deep bowl.
Take the temperature of each every 10 minutes.
Write down how long each takes to fall below 40C.
Real leftovers go into the fridge within 2 hours, so cool them this way too.

What you should find

The shallow dish cools in roughly half the time, because it has more surface for heat to escape.

From the app

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Step-by-step mode with timers, in the free app.

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The science behind it

Cool leftovers quickly

A deep pot of soup loses heat slowly from its center. Bacteria multiply fastest between 4°C and 60°C (40 to 140°F), and a full stockpot put straight into…

Read the explainer

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