Thermometer

The Chicago Partnership for Health Promotion is funded by the USDA Food Stamp Program to encourage Chicago

families to make healthier food choices, learn to prepare and consume healthier foods every day and be more

physically active. The University of Illinois at Chicago Neighborhoods Initiative is the Land Grant Administrative

Hub for CPHP. The USDA, UIC and CPHP are equal opportunity providers and employers. For more information

about partnership or CPHP programs in your community, contact CPHP at 312-355-3659. www.cphp.uic.edu









Cooperative Extension in Lancaster County

444 Cherrycreek Road, Suite A, Lincoln, NE 68528

Phone: 402-441-7180 Web site: lancaster.unl.edu/food





Pass the Taste Test …Use a Thermometer!

Alice Henneman, MS, RD, Extension Educator

and

Joyce Jensen, Registered Environmental Health Specialist,

Lincoln-Lancaster County Health Department

Recipe directions often

say to cook a food until

“done.” What is “done?” Inserting a Thermometer

While we worry about Insert thermometer in the center at the thickest part of

cooking a food long enough the food away from bone, fat or gristle.

for safety, we also should be

BEEF, PORK or LAMB ROASTS. The

concerned about cooking it

food thermometer should be placed midway in

too long to taste good. We can

the roast, avoiding the bone. Irregularly

assure 100% safety if food is

shaped foods, such as beef roasts, should

cooked until it tastes and

have their temperature checked in sev-

looks like cardboard, a piece

eral places.

of shoe leather or a hockey

puck — no one will eat it! THINNER FOODS such as

Webster’s dictionary MEAT PATTIES, PORK CHOPS and CHICKEN BREASTS.

defines “doneness” as “the An instant-read thermometer may be inserted sideways — if neces-

condition of being cooked to sary — in the thickest part, away from bone, fat, or gristle. Insert so

the desired degree.” Besides a the entire sensing area is positioned through the center of the food.

safe temperature, another USDA encourages people to use digital instant-read thermometers

aspect of “doneness” deals for thinner foods — digital thermometers don’t need to be inserted

with subjective qualities such as far as dial instant-read thermometers.

as the appearance, texture and

optimum flavor of a food. CASSEROLES and

other COMBINATION

DISHES. Place a ther-

Using a food

mometer into the thickest

thermometer is the

portion of the food or the

only way to accurately

center of the dish. Egg

determine a safe

dishes and dishes contain-

internal temperature

ing ground meat and

is reached.

poultry should be checked

in several places.

Here are some tempera-

ture guidelines, using U.S. Check manufacturer’s instructions as to how far the thermometer

Department of Agriculture must be inserted in a food to give an accurate reading. If instruc-

(USDA) and U.S. Food and tions are not available, check the stem of the thermometer for an

Drug Administration (FDA) indentation or “dimple” that shows the end of the sensing device.

recommendations. These will The probe must be inserted the full length of the sensing area. For

help ensure cooking to a dial instant-read thermometers, this is usually 2 to 3 inches and less

“doneness” that is both SAFE for digital instant-read thermometers.

and GOOD-TASTING.

University of Nebraska Cooperative Extension educational programs abide with the non-discrimination policies of the University of Nebraska-Lincoln and the United States Department of Agriculture.

Common Food Thermometers

Some types of thermom- temperature of a thin food, and the

eters commonly used in the such as a hamburger patty or thermom-

kitchen include: boneless chicken breast, insert eter probe

probe sideways with the is placed

Dial Oven-Safe (Bi-

sensing device in the center. in the

metal) Designed to stay in

About 15 to 20 seconds are food. An

food during cooking. Insert

required for the temperature to advantage

2 to 2-1/2 inches deep in the

be accurately displayed. of this thermometer is the ease

thick-

of tracking food temperatures

est part Digital Instant-Read

while maintaining oven heat.

of the (Thermistor) Not designed to

food, stay in food during cooking. Disposable Temperature

at the The heat sensing device is in Indicators (Single-use) —

begin- the tip Designed to be used only once

ning of of the for a specific temperature range.

the cooking time. It remains probe. Temperature-sensitive material

there throughout cooking and Place changes

is not appropriate for thin the tip color

food. of the when

probe in the

Dial Instant-Read

the center of the thickest part desired

(Bimetal) Not designed to

of the food. About 10 seconds tem-

stay in food during cooking.

are required for the tempera- perature

Insert probe the full length of

ture to be accurately displayed. is

the

reached. Should only be used

sensing

with food for which they are

area, Oven Cord — Fre-

intended. Place approximately

usually quently used in foods such as

1/2" deep (follow

2 to roasts and turkeys during

manufacturer’s directions).

2-1/2 cooking in the oven. The base

Reads in 5-10 seconds.

inches. If measuring the unit sits on stovetop or counter





Tips for Using Thermometers

✓

❏ Use a clean thermometer that has been washed in hot soapy water and hot rinse water before and

after use. Most thermometers should not be immersed in water — check manufacturer’s directions.

✓

❏ To prevent overcooking, begin checking the temperature toward the end of cooking but before the

food is expected to be “done.”

✓ Bacteria normally are found only on the external surface of larger cuts of meat like beef roasts and

❏

beef steaks. Beef roasts and beef steaks can be considered safe if cooked to 145º F in the center

since the outside will reach a temperature high enough to kill bacteria on the surface. When meat

is ground up or mechanically tenderized, bacteria on the surface can get mixed throughout the

meat and the meat must be cooked to an internal temperature of 160º F. Mechanically tenderized

meat has been punctured or injected, which can introduce bacteria into the center of the meat.

When foods are cooked to less than 160º F, wait until toward the end of the cooking period

before inserting a thermometer. Otherwise, it is possible bacteria from the outside could be trans-

mitted to the inside.



-2-

RECOMMENDED FOOD TEMPERATURES

These temperatures are recommended by the U.S. Department

of Agriculture and U.S. Food and Drug Administration for consum- Celsius Conversion Table

ers. They are not intended for processing, institutional or 32º F = 0º C

foodservice preparation. Foodservice workers should consult their 140º F = 60º C

state or local food code, or health department. 145º F = 63º C

Never partially cook food for finishing later because this 160º F = 71º C

increases the risk of bacterial growth on the food. Bacteria are 165º F = 74º C

killed when foods reach a safe internal temperature. When prepar- 170º F = 77º C

ing food in the oven, set the oven to at least 325º F. 180º F = 82º C

325º F = 163º C

TEMP.

FOOD (ºF) TIPS

Casseroles/Combination Dishes and Leftovers

Casseroles/Combination 165º F At this temperature, the food will be hot and steamy

Dishes and Leftovers throughout, a measurement that can only be determined by a

food thermometer. Thoroughly cook meat and poultry before

combining with other ingredients in casseroles and

combination dishes.

Eggs and Egg Dishes

Eggs 160º F * * It is very difficult to insert a thermometer into these

(poached, fried, scrambled forms of eggs and it is necessary to rely on a visual

and hard-cooked eggs) indicator. Cook so both yolks and whites are firm, not runny.

Egg Dishes 160º F At 160º F, eggs will

(soft stirred custard, baked be thick enough to coat a

custard, pumpkin pie, strata, metal spoon with a thin

quiche, bread pudding, film for soft stirred

hollandaise sauce, etc.) custards. For other egg

dishes, such as quiche, a

knife inserted near the

center should come out

clean.

Ground Meat and Poultry

Ground Beef, Veal, 160º F Cutting into cooked ground meat and using color as an

Lamb, Pork, Bison and indicator of safety is no longer considered reliable. Some

Game Meat ground meat may turn brown before it has reached a

(game meat includes deer, temperature that destroys bacteria. A hamburger cooked to

elk, moose, caribou, antelope 160º F, measured with a food thermometer throughout the

and rabbits) patty, is safe regardless of color.

Hamburger patties are a common ground meat food.

A 1/2 inch thick ground beef patty is more likely to cook

thoroughly in the middle without being overdone on the

outside than one that is too thick. A pound of beef, before

cooking, yields 4 patties measuring approximately 1/2" by 4.”

Ground Poultry 165º F Ground poultry is cooked 5 degrees higher than ground

(turkey and chicken) beef, veal, lamb and pork.

-3-

FOOD TEMPERATURE TIPS

Hot Dogs, Luncheon Meats, Cold Cuts, Fermented and Dry Sausage, and

other Deli-Style Meat and Poultry Products

Hot Dogs, Heat these ready-to-eat * People at risk for listeriosis include: pregnant

Luncheon foods until steaming hot women and newborns, older adults, and people

Meats, Cold throughout to help protect with weakened immune systems caused by cancer

Cuts, Fermented susceptible populations treatments, AIDS, diabetes, kidney disease, etc.

and Dry from listeriosis.* Although these foods are fully cooked, they can

Sausage, and become contaminated with Listeria

Other Deli-Style monocytogenes. Heat these foods until they are

Meat and Poultry steaming hot throughout.

Products



Large Cuts of Beef, Veal, Lamb, Bison

Large Cuts of 145º F - medium rare * CAUTION: Do not serve any rolled,

Beef, Veal and 160º F - medium tenderized or scored large cuts of beef, veal or lamb

Lamb: Roasts 170º F - well done below 160º F. The process of cutting or puncturing

and Steaks 160º F - all rolled, meats before cooking may force any surface

tenderized or bacteria into the center. When in doubt as to how a

scored meats.* piece of meat has been handled, cook to

160º F.

Large cuts of beef, veal or lamb — like roasts

and steaks — can stay slightly pink in the center if

they have reached at least 145º F. Beef roasts cooked

to 160º F will generally have very little pinkness to

the meat, and the juices will not be pink or red.

A consumer would not be able to determine if a

roast that was pink in the center had reached 145º F

without a food thermometer.



Pork

Pork Chops and 160º F Pork chops may have just a trace of pink color

Roasts at this temperature. Pork roasts are safe when

cooked to 160º F even though the center of the roast

may be somewhat pink. A consumer would not be

able to determine visually if a pork roast that was

pink in the center had reached a safe temperature.



Ham 160º F - purchased “fresh” Both vacuum-packaged fully cooked hams and

or described as canned hams can be eaten cold just as they come

“cook-before- from their packaging. However, if you want to heat

eating” these fully cooked hams, set the oven no lower than

140º F - purchased fully 325º F and heat to an internal temperature of

cooked 140º F.

165º F - reheated or For fully cooked ham that has been repackaged

repackaged from its original manufacturer’s packaging or for

leftover fully cooked ham, heat to 165º F for

greatest safety.



-4-

FOOD TEMPERATURE TIPS

Poultry

Chicken 180º F - whole Poultry will generally reach a safe temperature (160º F)

and 180º F - thighs and before it is “done.” At 160º F, harmful bacteria have been

Turkey wings destroyed, but poultry will still be pink and raw looking near the

170º F - breasts bone, and the juices will be pink and/or cloudy. By 170º F for

white meat and 180º F for dark meat, the flesh of poultry will no

longer be pink and the juices will be clear. With

whole chickens and turkeys, the joints will move

easily. This is an example of recommending a

higher internal temperature than is needed for

safety to assure attaining desirable quality aspects

of “doneness.”

When cooking whole poultry, the food

thermometer should be inserted into the thickest

part of the thigh (avoiding the bone).

If cooking poultry parts, insert food

thermometer into the thickest area, avoiding the

bone. The food thermometer may be inserted

sideways, if necessary. When the food is irregularly

shaped, the temperature should be checked in

several places.

Stuffing 165º F - in casserole CAUTION: The safest way to cook stuffing is in a casserole

or in turkey in a 325º F oven. The internal temperature of the stuffing must

reach 165º F.

Today’s turkeys cook faster than in the past as they now are

bred to have a greater portion of breast meat that cooks faster

than dark meat. If you stuff your bird, you take the chance of

your turkey becoming overdone before your stuffing has reached

a safe temperature.

The ingredients for the stuffing can be prepared ahead of

time. Keep wet and dry ingredients separated and chilled. Mix wet

and dry ingredients just before putting stuffing into a casserole or

filling the turkey cavity. If you choose to stuff your turkey, make

sure it is stuffed loosely. The stuffing should be moist, not dry,

since heat destroys bacteria more rapidly in a moist environment.

Cook a turkey immediately after stuffing it. If a turkey is

stuffed, the center of the stuffing should be checked after the

thigh reads 180º F. Check the temperature in the innermost part

of the thigh and in the center of the stuffing. Even if the thigh has

reached a safe internal temperature of 180º F, the center of the

stuffing inside the turkey may not have reached 165º F and can

cause foodborne illness. BOTH temperatures of 180º F for the

turkey and 165º F for the stuffing must be met.

Duck and 180º F - whole The same precautions and temperatures apply as with

Goose 180º F - thighs and chicken and turkey. USDA recommends cooking whole poultry

wings to 180º F as measured in the thigh using a food thermometer.

170º F - breast When cooking pieces, the breast should reach 170º F internally.

Drumsticks, thighs and wings should be cooked until they reach

an internal temperature of 180º F.



-5-

FOOD TEMPERATURE TIPS

Seafood

Fin Fish The FDA 2001 Food Code When you slip the point of a sharp knife into the

recommends cooking most flesh and pull aside, the edges should be opaque

seafood to an internal and the center slightly translucent with flakes

temperature of 145º F for beginning to separate. Let the fish stand three to

15 seconds. When using the four minutes to finish cooking.

microwave, rotate the dish

several times to ensure even

Shrimp, cooking. Follow Should turn red and the flesh should become pearly

Lobsters and recommended standing opaque.

Crab times. After standing time is

Scallops completed, check seafood in Should turn milky white or opaque and firm.

several spots with a meat

Clams, thermometer to be sure the Watch for the point at which their shells open. That

Mussels and product has reached the means they’re done. Throw out those that stay

Oysters proper temperature. closed.







Calibrating a Thermometer

To assure the accuracy of a thermometer, Ice Water Method

check — and adjust if necessary — by compar- 1. Fill a large glass with finely crushed ice.

ing its temperature reading with the temperature 2. Add clean tap water to the top of the ice and

of a known standard. This process is called stir well.

calibrating a thermometer. 3. Immerse the food thermometer stem a

How often a thermometer is calibrated will minimum of 2 inches into the mixture,

depend on use. Calibrate a thermometer when- touching neither the sides nor the bottom of

ever it is dropped and when first purchased. If a the glass. Wait a minimum of 30 seconds

thermometer is used frequently, calibrate it before adjusting. TIP: For ease in handling,

weekly or monthly. On the other hand, if it has the stem of the food thermometer can be

been several months since it has been used, placed through the clip section of the stem

calibrate it before use. sheath and, hold the the sheath horizontally,

Some thermometers can be calibrated by lowered into the water.

turning an adjusting nut under the head of the 4. Without removing the stem from the ice,

thermometer. Check manufacturer’s instruc- hold the

tions. The easiest way to calibrate a thermom- adjusting

eter is with the ice water method. nut under

Even if a food thermometer can’t be the head of

calibrated, it should still be checked for accu- the ther-

racy, as described in the ice water method. Any mometer

inaccuracies can be taken into consideration with a

when using that food thermometer, or the food suitable

thermometer can be replaced. tool and

For example, if a thermometer is checked turn the

by the ice water method and reads 34º F instead head so

of the recommended 32º F, it is reading 2 the pointer

degrees too high and 2 degrees would need to reads

be ADDED to final cooking temperatures. 32º F.

5/04 -6-