Most kitchens keep logs because the inspector asks to see them. For the sheets to tell you anything about the equipment, though, the numbers on them have to be real.
Getting readings you can use
Take readings at about the same times each day so you’re comparing like with like. Write the actual number, 37 or 39, instead of a checkmark, with initials beside it. When something’s off, add a short note about what you did (“moved dairy to reach-in 2, called for service”). And be a little suspicious of a month when the same person wrote 38 every single day. Real readings wander a degree or two. A flat line sometimes means the thermometer is stuck, and sometimes it means nobody’s looking at it.
What the patterns usually mean
The most useful thing a log can catch is a slow climb. A box that sat at 36 all spring and now sits at 39 is losing capacity, and dirty condenser coils are the most common reason, and they’re cheap to fix, though a slow refrigerant leak looks about the same on paper.
If the afternoon reading is always higher than the morning one, think about what happens in your afternoons. Deliveries come in, dinner prep starts, the kitchen heats up around any self-contained units, and a rooftop condenser sits in full sun. Our post on why walk-ins run warm on summer afternoons goes into that.
Freezers and some coolers go through defrost a few times a day. If a reading happens to land during defrost, it’ll be higher for a short while, so one odd number that’s back to normal an hour later usually isn’t a problem.
It also helps to compare units. When every cooler in the building reads warm at once, look at what they have in common, like the kitchen temperature or the power supply. One warm box on its own points back at that box.
With freezers, watch for readings that wander up from 0 toward 10 and back. That often lines up with ice building on the coil, which means the defrost system or the door is letting you down. The guide to freezer icing explains what to look for.
When to stop watching and call
If a cooler is trending toward 41, or a freezer keeps drifting up and doesn’t come back, call before it crosses the line. A system that’s struggling is usually cheaper to fix than one that’s quit, and you’ll still have your product. Hand the tech the last few weeks of logs. A trend tells them a lot more than one reading does.
Keep the old sheets.
If you ever have to file a claim for lost product, records showing the box holding fine right up to the failure can help. If paper logs keep getting skipped in your kitchen, our temperature monitoring page covers the record keeping side.
