***************UPDATE******************
Cook’s made this video into a “members only” thing, so here’s the skinny on how to test your oven temperature:
Put your oven rack in the middle of the oven. Heat the oven to 350 degrees Fahrenheit for at least a half hour. Put a half cup of 70 degree tap water in your 2 cup Pyrex measuring cup (you can fuss with it by adding hot or cold water to adjust the temp – it’s important that it be at 70 degrees to start with). Place the measuring cup in the oven and close the door. After 15 minutes, take the measuring cup out of the oven and take the water’s temperature with your thermometer. Swirl the water around to make sure the temperature is even. The thermometer should read 150 degrees Fahrenheit.
***************END UPDATE******************
Leave it to Cook’s Illustrated…I was just looking over their latest email newsletter and found this!
It’s a video on how to check your oven temperature with an instant read thermometer and a glass of water. Much cheaper than buying a damn oven thermometer for twenty bucks (who just did that? Oh, why me of course!).
Not sure about that whole “if your oven is off by more than a couple of degrees, it should be calibrated by a professional” thing, but this is still an outstanding (and if you already have a candy thermometer* essentially free) way of checking your oven temperature.
Cheers.
(Note – this particular candy thermometer costs as much an an oven thermometer and you can get them for much less money, but this is the one I have and I didn’t want to link to something I hadn’t used. Even if you get this one for $20, it’s still way more useful than an oven thermometer, so you save having to have two tools to do the same thing!)
[...] off. How off? Not even going to measure it off. Yours may be too, that’s why you should test it. Or don’t and just obsessively check on your baked goods and use your eyes to judge when [...]
I really wanted to see this video but I am not a member of Cook’s. Damm I guess I will have to buy a thermometer.
Hey Kathy! I’m glad you put up this comment – I had no idea that Cook’s had made the video “members only.” I just posted instructions on how to test the oven with an instant read thermometer, a Pyrex measuring cup and some water. Hope that helps!
Thanks for posting the instructions. I had that specific ATK show recorded on my DVR but then I lost the recording. I just did the test tonight and my thermometer read 164 instead of 150. I have a fairly new oven and I can adjust the temperature, but I’m not sure what to do. Any ideas? lisa
Thanks for posting those instructions! Extremely helpful for anyone wanting to test their oven temperature.
.-= oregon wireless meat thermometer´s last blog ..Talking Wireless Meat Thermometer =-.
FYI
I saw America’s Test Kitchen “Everyone’s favorite Cake” and Chris Kimball said 1 cup of water not half
What do I do if the temperature is off – my oven will allow me to adjust temp – if temp is below 150 degrees how do I determine amount to adjust?
I’m sorry to say that I don’t have any really good advice for recalibrating ovens. You can adjust your oven up or down (depending on if if it’s slow or fast) 150 degrees and see if you get better results. Some ovens are adjustable and if you bought it, it should have instructions that might include how to recalibrate. If not, you might have to have it serviced, which is probably the best way to go anyway if your oven is that far off and you want it really accurate. Hope that helps!
water boils at 212F,
with added heat, liquid water will remain 212F until converted to steam,
how do get the water to remain liquid to 350F?
You are right! I adjusted the post because I thought it was incorrect. The temperature should read 150 degrees Fahrenheit, not 350 (which would be impossible).
I was just about to spend that $20. on an oven thermometer, but the responses on Amazon.com to the various meters was so varied. You’ve not only saved me money, but I feel assured the results of your method will be accurate. Thanks.
Should the oven be set at 350 for 30 minutes then the water should be 150 after 15 minutes?
Hi Jeff – that’s correct! You can swirl the water around a bit when you take it out of the oven to make sure the water temperature is even.
Do you shut the oven off after the half hour or leave it on?
Hi Chris. You should heat the oven for 30 minutes and then let the Pyrex with water sit in the oven while it’s on for 15 minutes. Hope that helps!
Kathly, – yes it does. Trying it now. Thanks.
Dear,
i want to know for how long to keep the oven thermometer in oven to check the required temperature.
i bought the thermometer but still i am not able to understand my oven temperature.my thermometer does not stop on any degree,it keeps on rising or falling.i am very worried.
i put for 5 mins also and during whole baking,it keeps on rising on both conditions.although,i kept the oven on low and high flame both,but not getting the right temperature reading.
my question is will the thermometer stop on the required temperarture?
is it to keep the thermometer during whole baking process?
how long to keep the thermometer in oven to check the temperature?
plz reply.will be very thankful to you
I really do not know the answer to your questions. I do know that ovens do not stay at one temperature consistently, but fluctuate around the temperature you set them at. If you’re not having a hard time cooking things properly in the oven, then I would say that your oven is fine. If it is hard to cook things (if they are always underdone or always burning), I would have a professional look at it. Hope that helps!