Cold Chain Management in Winter: Why Cold Weather ≠ Safe

Partial thaw and refreeze cycles are especially problematic in winter. Frozen products can partially thaw during loading, transport, or unloading, then refreeze in cold outdoor air before you ever check them. While this cycle may not impact food safety, it does impact food quality and can lead to ice crystal formation that hide previous thaws.

The 2022 Food Code is clear: potentially hazardous foods must stay below 41°F or above 135°F. What may not be so clear is that outdoor temperature doesn’t really count as controlled refrigeration.

Your receiving SOP is your primary defense against compromised product. Start before the truck arrives by communicating with suppliers and carriers. Confirm that refrigerated units maintained proper temperatures throughout transit, verify that seals on refrigerated compartments remained intact, and get an estimated arrival time so staff can prepare the receiving area and minimize door-open time.

When the delivery arrives, conduct a thorough visual inspection before accepting anything. Check all packaging for tears, crushing, or wetness that suggests temperature abuse. Look for excessive ice buildup or frost on frozen items, which often indicates previous thawing. Examine products for signs of partial thaw: soft spots on frozen items, ice cream that’s reshaped in the container, or frozen vegetables clumped together in solid blocks.

Use a calibrated thermometer and check internal temperatures, not just surface readings. For frozen foods, insert the probe between packages or into the product itself when possible. Frozen foods must be…well, frozen! Refrigerated items must be 41°F or below. Check multiple items and multiple locations in the delivery, especially products in the middle of stacks where temperatures may have fluctuated.

Once you accept a delivery, move quickly. Transfer refrigerated items to proper storage quickly.  Stagger deliveries when possible so staff can properly inspect and store each load before the next arrives.

Proper storage is only as good as your monitoring system. Install thermometers in the warmest part of each refrigeration and/or freezer unit. This is typically near the door but away from vents that give false readings. Consider purchasing a temperature monitoring system. Most systems can now send direct warnings via text message to cell phones of managers and supervisors to alert them to any issues before they become a situation where you must destroy or dispose of product.

Check and record temperatures of your storage units at least twice daily, once at opening and once mid-day or closing. Increase checks during temperature extremes, after winter storms that may have caused power fluctuations, and any time a unit’s door has been left open. If temperatures drift out of range, take immediate action.

The cold weather of winter creates a false sense of security that can compromise your entire operation. Temperature abuse leads to foodborne illness, product loss, and damage to bottom line and reputation. This week, audit your current cold chain procedures, and verify that all thermometers are calibrated, and temperature logs are current. Diligence now prevents a crisis later. Risk Nothing.