What The Heck is a Food Thermometer Anyway?

Until I became a chef I did not use a food thermometer. Yet it is an important tool to use when cooking. Cold foods should stay cold 41˚F (5˚C) or below. Hot food should stay hot 135˚F (57˚C) or above. When foods are kept between theses temperatures pathogens begin to grow, which can and will make people sick. Pathogens is another word for germs.

You can buy a dial or digital type food thermometer at any store that sells kitchen house wares. Below is a picture of a food thermometer and all its parts.

Parts of a Thermometer

1. Thermometer Head

2. Full Thermometer 

3. Full Thermometer with Cover

In the first picture, you see the head of a standard thermometer looks like. In the second picture, you see what a full thermometer looks like. In the third picture, you see the thermometer in its protective cover.

1. Head 2. Nut 3. Stem 4. Dimple 5. Sensing area

In the picture, you have 1. the Head of the thermometer.  2. Just under the head is the adjusting nut. 3. The stem 4. The dimple about 3/4 of the way down the stem. 5. from the dimple to the tip is the sensing area.

When using a thermometer to check the food you are cooking

1. Insert the thermometer in the thickest part of the food such as a roast.
2. Insert the stem into the food making sure to go past the dimple, this is the
3. sensing area to get a proper reading.
4. When you are checking the temperature of thin cuts of food you need to hold
5. the item with a pair of tongs and place the thermometer into the side of the
6. food, making sure that it goes past the dimple.
7. Wait until the needle moves and comes to a stop, before pulling out the thermometer.
8. If the targeted internal temperature is not reached continue cooking the food.
9. Remember to clean and sanitize after each use with rubbing alcohol, or another sanitizer to clean the thermometer.
10. Another thing to remember is, do not let the tip of the thermometer touch the bottom of the cooking pan as you will get a false reading.

Calibrating a Thermometer

Calibrate your thermometer before using it, and also if you drop it. This will make sure you will get a correct reading. Also, make sure to clean and sanitize the stem before each use.

1. To use the ice water method, fill a large glass with finely crushed ice. Add clean cold tap water to the top of the ice and stir well
2. Immerse the food thermometer stem a minimum of 2 inches into the mixture, touching neither the sides nor the bottom of the glass.
3. Wait a minimum of 30 seconds before adjusting. (For ease of handling, put the stem of the food thermometer through the clip section of the stem sheath and, holding the sheath horizontally, lowered into the water).
4. Without removing the stem from the ice, hold the adjusting nut under the head of the thermometer with a suitable tool and turn the head so the pointer reads 32 degrees.
5. Thermometers need to be accurate to within +- 2 degrees Fahrenheit or  +- 1-degree Celsius.

Thermometer in Ice Water Using Cover to Hold

4. Hold the adjusting nut under the head of the thermometer with a suitable tool and turn the head so the pointer reads 32 degrees. Here are three types of nuts on a food thermometer. (See Pic below)

Different Type Nuts on Thermometer

• From left to right the first thermometer has a hex nut where you would have to use small pliers to adjust.
• The second one has a wing nut type that you can just use your hand to adjust.
• The third one has a hex nut with slots in it where you would use the clip on the cover to adjust the nut.
• Thermometers need to be accurate to within +- 2 degrees Fahrenheit or  +- 1-degree Celsius.
• There is a second way to check the accuracy of a thermometer and that is the boiling water method. I am not discussing this way because I believe it is dangerous.

Picture courtesy of USDA website

List of foods and their proper cooked temperature

These are the temperatures that the food must reach. This will keep the food safe.

1. 135˚F  (57˚C) Cooked fruits, vegetables, grains and beans.
2. 145˚F  (63˚C) (for 4 minutes) Beef, pork, veal, lamb roast.
3. 145˚F  (63˚C) (for 15 seconds) Beef steaks, pork, veal, lamb chops and all whole cuts of seafood.
4. 155˚F  (68˚C) (for 15 seconds) Ground beef, pork, lamb, and seafood.
5. 165˚F  (74˚C) (for 15 seconds) Poultry, whole and ground chicken and turkey. Any stuffed meats such as chicken breasts, pork chops or turkey.

The two-stage cooling time requirements for food.

When making large batches of food such as soup you cannot put the large batch right into the refrigerator, you must cool the food down first. Following the guidelines below will ensure that your food will remain safe.

1. stage one:135°F to 70°F (57.2 °C to 21.1°C) within two hours. 2. Stage two: 70°F to 41°F (21.1°C) or lower within four hours.

One of the best ways to get the food cooled down quickly is to use an ice water bath. To do this;

1. Put a large plate upside down in your sink. 2. Place the food you need to cool down in the center of the plate. This is to help the food to cool from the bottom of your container.                                               3. Cover food and fill the sink with cold water and ice. You need to add enough  water and ice so it goes past the level of food you have in your container.           4. Once the water and ice are filled, take off the lid and on occasion stir the food  until it reaches 70°F – (21.1°C) If  the temperatures are not down to 70°F (57.2 °C) in two hours or 41°F ( 21.1°C) in 6 hours You have two options, one reheat the food to 165°F (73.9°C) and start the cool down process again, or option two, throw the food out.

The above information I have had to learn in order to do my job as a supervisor. The company that I worked for said we needed to be certified every three years and the USDA requires every five years.

So when you go into a restaurant and see ServSafe certificates on the wall, you can feel confident that the management and chefs are being certified, and keeping the food safe that you eat.