Two-stage cooling, explained

The two-stage cooling rule

Cooked food that needs time and temperature control has to get cold fast, in two stages. This is section 3-501.14(A) of the FDA Food Code 2022:

FDA Food Code 2022, 3-501.14(A)(1)

Within 2 hours from 57ºC (135ºF) to 21ºC (70°F)

FDA Food Code 2022, 3-501.14(A)(2)

Within a total of 6 hours from 57ºC (135ºF) to 5ºC (41°F) or less

In kitchen terms: from 135°F (57°C) to 70°F (21°C) within 2 hours, then all the way to 41°F (5°C) or below within 6 hours of the start. Both clocks start at the same moment. That is why people call it the 2-hour, 6-hour rule, and why the second stage only gets 4 hours if the first stage uses all of its 2.

Why two stages? The spores that survive cooking, such as Clostridium perfringens and Bacillus cereus, grow fastest in the warm upper part of the danger zone. The Food Code's public health reasons in Annex 3 call the first stage out directly: an initial 2-hour cool is a critical element, and a batch that reaches 41°F within 6 hours but took 3 hours to reach 70°F may not be safe.

FDA Food Code 2022, Annex 3, public health reason for 3-501.14

but the initial cooling to 70ºF took 3 hours, the food safety hazards may not be adequately controlled.

Here is what that failure looks like. The total time is fine on paper; the first checkpoint is not.

Which foods follow which cooling rule

Section 3-501.14 has three cooling rules. Most kitchens only need the first, but the other two catch people out.

FDA Food Code 2022, 3-501.14(B)

shall be cooled within 4 hours to 5oC (41oF) or less if prepared from ingredients at ambient temperature

Sous vide and cook-chill bags follow the same 2-hour and 6-hour rule, inside the sealed bag:

FDA Food Code 2022, 3-502.12(D)(2)(e)

Cooled to 5°C (41°F) in the sealed PACKAGE or bag as specified under § 3-501.14

For bags, that is the first step of the storage rules in 3-502.12(D)(2)(e). See the sous vide guide.

Worked example: a pot of braised short rib

A hotel pan of braised short rib comes out of the oven well above 135°F. The cook portions it into shallow pans, sets them in an ice bath, and probes the center as it drops.

1. 2:00 pm 135°F Clock starts. Write down the time and temperature.
2. by 4:00 pm 70°F or below First checkpoint, 2 hours after the start.
3. by 8:00 pm 41°F or below Done, 6 hours after the start. Into cold holding.

The deadlines come straight from the rule: 2:00 pm plus 2 hours is 4:00 pm; 2:00 pm plus 6 hours is 8:00 pm. Neither moves, even if the first stage goes fast.

Fast is still good, though. Annex 3 gives this example:

FDA Food Code 2022, Annex 3, public health reason for 3-501.14

An example of proper cooling might involve cooling from 135ºF to 70ºF in 1 hour, in which case 5 hours remain

So if the short rib reaches 70°F at 3:00 pm, the cook has until 8:00 pm to reach 41°F: the same final deadline, with more room to get there.

Cooling methods that pass

The Food Code lists the methods it accepts in 3-501.15. Here is the list, word for word:

FDA Food Code 2022, 3-501.15(A)

Cooling shall be accomplished in accordance with the time and temperature criteria specified under § 3-501.14 by using one or more of the following methods based on the type of FOOD being cooled:

1. Placing the food in shallow pans; 3-501.15(A)(1)
2. Separating the food into smaller or thinner portions; 3-501.15(A)(2)
3. Using rapid cooling equipment; 3-501.15(A)(3)
4. Stirring the food in a container placed in an ice water bath; 3-501.15(A)(4)
5. Using containers that facilitate heat transfer; 3-501.15(A)(5)
6. Adding ice as an ingredient; 3-501.15(A)(6)
7. Other effective methods. 3-501.15(A)(7)

And once the food is in the cooler or walk-in:

FDA Food Code 2022, 3-501.15(B)

When placed in cooling or cold holding EQUIPMENT, FOOD containers in which FOOD is being cooled shall be:

• Arranged in the EQUIPMENT to provide maximum heat transfer through the container walls; 3-501.15(B)(1)
• Loosely covered, or uncovered if protected from overhead contamination as specified under Subparagraph 3-305.11(A)(2), during the cooling period to facilitate heat transfer from the surface of the FOOD. 3-501.15(B)(2)

What that looks like on the line

A method is only as good as the checkpoint it hits. Whatever you use, the probe decides.

What to do when a batch misses a checkpoint

Your HACCP plan sets the corrective action for cooling. The Food Code's Annex 5, written to guide inspectors, gives a widely used starting point. Here it is, word for word:

FDA Food Code 2022, Annex 5, section 7 (Assessing Cooling)

Cooked hot food may be reheated to 165 ºF for 15 seconds and the cooling process started again using a different cooling method if the food is:

• Above 70 ºF and two hours or less into the cooling process; and
• Above 41 ºF and six hours or less into the cooling process.

FDA Food Code 2022, Annex 5, section 7 (Assessing Cooling)

Cooked hot food should be discarded immediately if the food is:

• Above 70 ºF and more than two hours into the cooling process; or
• Above 41 ºF and more than six hours into the cooling process.

In plain words: a batch that is cooling too slowly but has not yet passed a checkpoint can be reheated to 165°F for 15 seconds and started again with a faster method. A batch that is past a checkpoint and still too warm is discarded.

FDA Food Code 2022, Annex 5, section 7 (Assessing Cooling)

such foods should be discarded if the food is above 41 ºF and more than four hours into the cooling process.

Annex 5 is guidance, not a rule your kitchen has to copy, and your health department may want your corrective action written differently. Write yours into the plan, then do what it says every time. FDA's one-page cooling fact sheet for food employees is a good poster for the walk-in door.

Every miss goes on the log with what you did, and on a corrective action log if your plan uses one. A pattern of misses means the method is wrong for that food, not that the cook is slow.

How to log two-stage cooling

A cooling log is how you prove the rule was met, and for sous vide and cook-chill it is a record the Food Code requires you to keep for at least 6 months (3-502.12(D)(3)(b)). A good log has one row per batch and these columns:

• Food and batch, so a reading ties to a pan or bag.
• Start time and temperature at 135°F.
• 2-hour check: time and temperature, target 70°F or below.
• 6-hour check: time and temperature, target 41°F or below.
• Method used (ice bath, shallow pans, blast chiller).
• Corrective action if a checkpoint was missed, and what happened to the food.
• Initials of the cook, and the person in charge's review.

Probe the thickest part. Annex 5 tells inspectors where they will measure:

FDA Food Code 2022, Annex 5, section 7 (Assessing Cooling) probe point

The geometric center of a product is often chosen as the point of measurement of product temperature particularly when measuring the critical limits for cooling.

Use a probe accurate to ±2°F if it reads in Fahrenheit only (4-203.11(B)) and calibrate it on a schedule.

Get the free cooling log

On ClearHACCP the same log runs on your phone: the clock starts when you enter the 135°F reading, the 2-hour and 6-hour checks come as reminders, and an out-of-limit reading shows your plan's corrective action on the spot.

Common two-stage cooling mistakes

• Starting the clock at 70°F. The 6 hours run from 135°F, so stage two gets what stage one leaves.
• Only checking at the end. By then a stage-one miss cannot be fixed by reheating under the Annex 5 guidance. Probe at the 2-hour mark.
• Deep containers and tight lids. A full stockpot with the lid on can sit in the danger zone for hours. Portion it and leave it loosely covered.
• Cooling in the line reach-in. It is opened all service and cannot pull the heat out fast enough.
• Probing the edge. The edge cools first. The center is the reading that counts.
• Logging temperatures without times. A cooling log without clock times proves nothing.

Cooling is a critical control point in every cook-chill and sous vide plan. ClearHACCP builds that CCP from the Food Code with the section printed beside every number, ready to submit. You sign it. Your health department decides.

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