What you need

  • A food thermometer accurate to within 2°F, handy wherever food is cooked, held or cooled.
  • A thin-tip probe for thin foods like burger patties and fish fillets.
  • A thermometer inside every fridge, freezer and cooler, in the warmest spot (near the door).
  • Never glass or mercury thermometers around food.

Sources: Food Code 4-203.11 · Food Code 4-302.12 · R392-102-8(15)–(16)

When to calibrate

  • Before using a new thermometer
  • Once a day, before you start
  • After it is dropped or damaged
  • Whenever a reading seems wrong
  • After a suspected foodborne illness, before relying on those logs

Record every calibration.

Sources: Source protocols: calibrating thermometers (when to calibrate)

Ice-water method

  1. Fill a large glass with crushed ice, then add cold water to the top. Stir.
  2. Put the probe in the center, not touching the sides or bottom. A dial thermometer goes at least 2 inches deep, past the dimple.
  3. Wait 30 seconds, or until the reading stops moving.
  4. It should read 32°F. If not, adjust it (dial: turn the nut under the head with a wrench; digital: press reset per the maker). Replace it if it can't be adjusted.

Do not use boiling water in Utah. Water boils at about 198–206°F here depending on elevation, not 212°F, so it can't confirm accuracy.

Sources: Source protocols: ice-point method; do not use the boiling-point method in Utah

Using and cleaning it

  • Digital thin-tip probe: best all-around tool. Probe the thickest part.
  • Dial thermometer: senses in the first 2–2½ inches; wait 15–20 seconds. Too thick for thin patties.
  • Infrared (laser) reads only the surface, never the inside of food.
  • In large items, probe two spots and use the lower reading.
  • Wash, rinse and sanitize the probe (sanitizer dip or 70% alcohol swab) between foods, and always between raw and cooked.
  • Don't soak a digital thermometer unless it's waterproof. Store it in its sleeve.

Sources: Source protocols: thermometers (types and use); sanitizing thermometers · Food Code 4-602.11

The rules behind it

  • Accurate thermometers. Food thermometers accurate to ±2°F; calibrate by ice point (32°F); not boiling water in Utah. Food Code 4-203.11, 4-302.12; R392-102-8(15)–(16)