Chilling Time Calculator

Work out chilling time instantly with clear inputs, formula shown and shareable results.

About Chilling Time Calculator

For an infinite slab cooled by convection, the centre temperature follows a one-term series solution: time scales with the square of half-thickness divided by thermal diffusivity, times the log of the temperature difference ratio. Thickness dominates — doubling it roughly quadruples chilling time.

Formula

Slab cooling

Time proportional to (half-thickness)^2 / thermal diffusivity x ln(4 g0 / (pi g))

Worked example

With the default values below, Chilling Time Calculator returns Chilling Time of 0.408. Change any input above and every figure here is recalculated in your browser.

Inputs used

Product Thicknessminimum 0.01 mm: 50 mm
Initial Temperatureminimum -20 degrees C: 65 degrees C
Target Core Temperatureminimum -20 degrees C: 5 degrees C
Chiller Air Temperatureminimum -40 degrees C: 1 degrees C

Results

Chilling Time: 0.408
Chilling Time In Minutes: 24.5
Initial Temperature Difference: 64.00
Final Temperature Difference: 4.000

Step by step

1Values used
2Slab cooling
3Chilling Time= 0.408
4Chilling Time In Minutes= 24.5
5Initial Temperature Difference= 64.00
6Final Temperature Difference= 4.000

Assumptions and limits

The result is derived only from the 4 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation, tax, fees or charges or compounding frequency into account.
Figures are rounded for display to 3 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Cooling rate requirements for cooked foods are set by food safety regulation. Verify core temperature against the applicable time-temperature limits rather than relying on calculation.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Cooling rate requirements for cooked foods are set by food safety regulation. Verify core temperature against the applicable time-temperature limits rather than relying on calculation.

Frequently Asked Questions

Why is thickness so critical?

Conduction time scales with the square of the distance heat must travel. Portioning a product thinner is by far the most effective way to speed chilling and meet cooling regulations.

What cooling rates are required?

Many food codes require cooling from 60 C to 21 C within two hours and to 5 C within a further four. Meeting that on thick products usually requires blast chilling or portioning.