Why We Lie About Using Food Thermometers

[MULTIZ321]

Why We Lie About Using Food Thermometers - by Nancy Shute/ The Salt: NPR's Food Blog/NPR.org


Richard

 

[MuranoJo]

Frustrating part about thermometers is you can use 4 different models and get 4 different readings (so which one do you trust?), or when you need them the most, the battery is dead. Plus, you need a different one for candy.

My new oven has one of those built-in thermometers, so I'll give it a try this year with the turkey.

 

[ScoopKona]

Frustrating part about thermometers is you can use 4 different models and get 4 different readings (so which one do you trust?), or when you need them the most, the battery is dead. Plus, you need a different one for candy.

My new oven has one of those built-in thermometers, so I'll give it a try this year with the turkey.

So, calibrate your thermometer.

Place it in ice water and see if it reads 32f/0c. Place it in boiling water and see if it reads 212f/100c (assuming living close to sea level, of course -- and if you know your elevation, correct accordingly). Any good thermometer can be calibrated. If it cannot, it isn't any good.

And the first thing to check is the oven. Most ovens are inaccurate. That's why cooks use a calibrated oven thermometer, rather than relying on the numbers written on the knobs.

 

[MichaelColey]

I don't lie about it. I only use a thermometer when I'm smoking meat in my smoker. Anywhere else, I go by the outside look and experience.

 

[ronparise]

"Stick a Fork in Me Im Done"

Heres what I learned as an Army cook 40 years ago...This works for large cuts of meat. I was cooking for a hundred troops and no one ever got sick on my watch (well except for the day the top came off on the chili powder and the whole can emptied into my 10 gallon pot of chili...it was good, but there were lines at the latrine the next day)

to test meat for doneness, stick a fork in it...if the juices that flow are clear...its done, If the juices still run red its not, pink and its rare....always cook pork and fowl until the juices run clear

for a bird, use the fork test and/or hold onto the end of the leg and wiggle it a little. If the joint feels stiff, its not done, if it moves freely than it is

be extra careful if you are cooking your turkey stuffed. An unstuffed bird cooks from the outside in and from the inside out (the air in the body cavity is hot too)...Stuff the bird and you lose the advantage of the empty (hot) body cavity, and the cooking time will be longer.

Also be sure to let your bird cool before you carve it...If you dont you will have something akin to pulled pork when to try to slice it....it will shred instead of slice

 

[laurac260]

Frustrating part about thermometers is you can use 4 different models and get 4 different readings (so which one do you trust?), or when you need them the most, the battery is dead. Plus, you need a different one for candy.

My new oven has one of those built-in thermometers, so I'll give it a try this year with the turkey.

Yes, my oven has that too. I use it whenever I cook a large portion of meat, so yes, I will be using it for Thanksgiving.

Word to the wise though. If your model is like mine, the second your bird reaches that magical temp you selected (170F), the oven shuts off. Don't find yourself in the basement watching the big game, or in the living room tending to the inlaws. Because when you go in the kitchen, you will find the oven off, and the bird only done in that one spot you stuck the thermometer in. You will check it a few more places and find that Tom isn't quite done, and your oven temp has dropped to 200F by now.

 

[laurac260]

And the first thing to check is the oven. Most ovens are inaccurate. That's why cooks use a calibrated oven thermometer, rather than relying on the numbers written on the knobs.

Here's what I learned from the service guy who replaced the motherboard on my oven last spring: The old ovens mom cooked on were much more reliable. Set it at 350F. The oven heats to 350F, then stops heating. As soon as the temp gets a bit below 350F the oven turns on, then off when it gets to 350F, etc. They were deemed major energy suckers.

The "new and improved ones" are much better. At conserving energy. Not so great at cooking in. He said that if you set your oven to 350F, the oven heats to close to 400, then shuts down till it gets to 250, then back up, looking for an "average" temp. Ever wonder why you can't make a decent baked good anymore??

My oven has a convection option on it. Unless I am slow roasting and plan on keeping the item in the oven a long time, I use the convection option. The oven stays at a more constant temp. Now I don't ruin my baked goods anymore.

 

[MuranoJo]

So, calibrate your thermometer.

Place it in ice water and see if it reads 32f/0c. Place it in boiling water and see if it reads 212f/100c (assuming living close to sea level, of course -- and if you know your elevation, correct accordingly). Any good thermometer can be calibrated. If it cannot, it isn't any good.

And the first thing to check is the oven. Most ovens are inaccurate. That's why cooks use a calibrated oven thermometer, rather than relying on the numbers written on the knobs.

I've tested a couple of oven calibration thermometers and gotten different readings on them, too.

I'll use a thermometer, and an oven thermometer, but I've gotten to the point my primary judgement will be as Ron mentioned, the old fallback: Are juices running pink? Do the legs freely move?

And I never trust those built-in thermometers which come with some turkeys. I always double-check those against other methods.

 

[ScoopKona]

I've tested a couple of oven calibration thermometers and gotten different readings on them, too.

I'll use a thermometer, and an oven thermometer, but I've gotten to the point my primary judgement will be as Ron mentioned, the old fallback: Are juices running pink? Do the legs freely move?

And I never trust those built-in thermometers which come with some turkeys. I always double-check those against other methods.

I never buy turkeys that have those little plastic "thermostats." But in the rare case that I'm stuck with one, I remove it and use the hole to insert a probe thermometer.

So calibrate your calibration thermometers. If they can't be calibrated, they are poor measuring instruments. Sticking forks and skewers into birds is fine. But knowing the temperature of one's oven is also the goal here. Most home cooks don't have a clue what they're really baking and roasting at.

And also, while the bird may be "done" when juices run clear. It's really done when the internal temperature reads 165f. No more than that. Any more than that is just drying out the bird. Wiggling legs isn't going to help an overcooked bird. And it just slows things down to constantly open the oven to check the bird. Better to have an accurate probe thermometer. Then the cook can pull the bird a few degrees below 165 and let carryover do the rest.

The things that (in general) separate home cooks from professional cooks:

1) Home cooks don't make or use nearly enough stock. Most don't know how.

2) Shallots. Home cooks don't use them. Most kitchens go through crates of shallots every day/week.

3) Compound butter. And fresh herbs. Home cooks don't make compound butter, and they don't know where/when to add fresh herbs.

4) Knowing the temperature -- with certainty -- in their ovens. Since they don't know what temperature they're cooking at, their roasts and baked goods are substandard.

5) The concept of carryover cooking. Most home cooks don't get that one.

6) Knowing how to brown and caramelize things. Most home cooks turn out gray "browned" meat. They steam instead of sauté. They overcrowd their pans. And Their pots aren't heavy enough to properly caramelize onions. So they make boiled onion soup instead of French onion soup.

7) Most home cooks have dull knives and bad knife skills. They don't cut things to a uniform size. So we end up with vegetable dishes with both undercooked and overcooked components.

There are plenty of home cooks who not only get all of the above, they're better at it than most professional cooks. But in general, the most home cooks should really work on the above seven things.

 

[MuranoJo]

OK, I can honestly say I passed all of your quiz except #4. Which is why I'm on this thread griping away. And I know it is a fundamental.

So where do I get a good 'calibration' thermometer for the oven?

(BTW, I'm a big Cook's Illustrated fan, but I'm almost afraid to tell you that, lest you dash my admiration. )

 

[ScoopKona]

OK, I can honestly say I passed all of your quiz except #4. Which is why I'm on this thread griping away. And I know it is a fundamental.

So where do I get a good 'calibration' thermometer for the oven?

(BTW, I'm a big Cook's Illustrated fan, but I'm almost afraid to tell you that, lest you dash my admiration. )

Get a thermometer with a calibration nut -- that way the thermometer can be adjusted. Then place it in something with a known temperature. A glass of R.O./distilled water filled with ice is close enough to 0c in most places. Boiling water at sea level is 100c. Tin melts at 217c/450f.

The problem with most oven thermometers is they can't be dipped in boiling water. But probe thermometers can. So calibrate a probe thermometer to 100c, and then use that to calibrate other thermometers. Otherwise, find some pure tin and melt it in the oven* in a Pyrex cup you intend to never use again. And then set your thermometer accordingly.

* Set for 350f and raise the temp 10 degrees every 10 minutes until the tin melts. Then calibrate the thermometer to 450f. Keep the slug of tin for other calibrations. They don't teach THAT one in Cook's Illustrated.

 

[MuranoJo]

* Set for 350f and raise the temp 10 degrees every 10 minutes until the tin melts. Then calibrate the thermometer to 450f. Keep the slug of tin for other calibrations. They don't teach THAT one in Cook's Illustrated.

Have to admit, I've not seen these tips in CI.
Why the heck can't we simply purchase a good, reliable thermometer?
Why can't they conduct these tests before they sell them? Essentially, it appears they are selling worthless products (I'll bet most folks don't bother with calibration).

 

[ScoopKona]

Have to admit, I've not seen these tips in CI.
Why the heck can't we simply purchase a good, reliable thermometer?
Why can't they conduct these tests before they sell them? Essentially, it appears they are selling worthless products (I'll bet most folks don't bother with calibration).

Because by their very nature, thermometers change over time, eventually degrading.

I'd rather have a dozen cheap thermometers and probes that are only going to last a year or two, than a $200 Williams Sonoma thermometer that is only going to last a year or two.

As long as the thermometer has a calibration nut/screw/button (for the digital ones), and you can calibrate it against a known temperature, you're good to go.

The exception to this is candy thermometers. They last and last -- because they're basic mercury thermometers. No bimetal laminates to degrade. Find an accurate candy thermometer, and you can use that to calibrate the rest.

 

[laurac260]

So I ran a test on my oven today. I heated it to 250f, stuck a meat thermometer in , and checked the temp 180f. Yesterday I had put the same thermometer in icewater and got a 33F reading, so I feel confident in it's accuracy +- 1degree. I then set the oven to convection , waited for it to heat , then tested again . My 220f max thermometer dial was "off the scale ", so I would give the convection setting a better rating for accuracy.

 

[MuranoJo]

Interesting and thanks for your test results.
Our new oven has a convection choice, but the directions that came with the oven are pretty cryptic and very minimal--so we don't play with it too much.

 

[ScoopKona]

So I ran a test on my oven today. I heated it to 250f, stuck a meat thermometer in , and checked the temp 180f. Yesterday I had put the same thermometer in icewater and got a 33F reading, so I feel confident in it's accuracy +- 1degree. I then set the oven to convection , waited for it to heat , then tested again . My 220f max thermometer dial was "off the scale ", so I would give the convection setting a better rating for accuracy.

You'll want to retry all that using boiling water as your reference point.

Whenever possible, you want to calibrate with a temperature that is closest to what the thermometer regularly measures. I use ice water only for my probe thermometer that I use in walk-ins, reach-ins and similar.

Use this calculator if you're not at sea level:

http://www.csgnetwork.com/h2oboilcalc.html