According to a test by Cook’s Illustrated in 2011, different ovens set to the same temperature can vary by as much as 90 degrees.
Yes….90 degrees.
If you are an avid baker or cook (or even just an occasional one), this news should be a bit concerning. Or maybe this news is relief; you now have a valid excuse for why your sweet potato fries always burn! Or at least I do…
When we moved in, one of the first things I did was check the oven’s true temperature. It’s an older oven (edited to add: I don’t mean super old by the way. The oven in our last house was 30 yrs old and I doubt this one is more than 10 yrs, so technically, it’s newer to me) and I was concerned about switching to a new-to-me oven without checking things out first. It’s especially important to me because I post my recipes for all of you and I have to be as accurate as possible.
For some reason, I had a bad feeling about this oven, even though it’s quite nice on the eyes.
I set my oven to 350F and placed my oven thermometer (from Kitchen Stuff Plus) in the center of the oven on the middle rack. This would be the first of several tests I would end up doing.
[But it’s called a “TRUE TEMP”…what could possibly go wrong???]
The oven beeps when it has supposedly finished preheating, so I eagerly walked over to the oven when it alerted me. I didn’t want to impact the temperature by opening the door, so I quickly turned on the oven light and bent down to look at the temperature.
The oven temperature read about 290F or so. I can’t quite remember it exactly, but it wasn’t even close! I gave the oven the benefit of the doubt, assuming that it just took longer to preheat.
And I waited some more. The temperature climbed slowly and after a good 15 minutes, I decided it wasn’t moving anymore. I waited an extra 30 minutes just to be sure.
I squinted my eyes really hard (am I getting old or are those things just really tiny?)
To me, it looks about 315-320F:
This is about a 30-35 degree difference. I also tested various places in the oven (on the side and in the back), but they were all around that temperature give or take 5 degrees. I even left it in for a full hour just to be sure. Nada.
Every good researcher knows that it’s to never advisable to rely on a single study, right? So, I headed out and bought another brand of oven thermometer (this time from Canadian Tire) and tested it once again.
Replicate.
Wouldn’t you know it, the temperature was the exact same. Approximately 320 degrees Fahrenheit when it should have been 350. At least the thermometers are accurate. ;)
I Googled if there was any way to fix my wonky oven temperature and it turns out that it’s fairly easy to calibrate many kinds of ovens, depending on the severity.
Always start with the manual first. I looked for the owner’s manual, but wasn’t able to locate one (not surprising being in a rental and all). Eric suggested that we find the model number of our oven and see if we could find instructions online. He wasn’t able to find the manual online for this oven.
Eric finally ended up finding directions on Appliance 411- “How do I adjust the oven temperature on my range?”.
Following these directions, he was able to set the oven temperature higher (35F was as high as he could go), however it’s still not a perfect calibration. Now, when I set the oven to 350F, it heats to about 340F, so it’s still about 10 degrees too low. To attain 350F, I have to set the oven to 360F and also wait about 5-10 minutes after the oven tells me it’s preheated. This isn’t a huge deal, as long as I’m careful and I keep my oven thermometer in the oven when using.
The oven thermometer is probably the best solution we have right now, aside from actually paying someone to repair it (or asking the landlord), which I probably wouldn’t bother with unless it got worse.
Our first adventure in oven calibration is now complete.
One thing I love about this oven? The stove top heats up much faster than our old oven back at home. You win some, you lose some! I’ve burned a few veggie burgers so far, but I’ll get used to it eventually.
Have you ever measured your oven’s true temperature or calibrated your oven? I bet you sure are curious now…
I remember my mom having a really old oven and it’s always a lot hotter than the temperature she sets it too. She ends up just adjusting all her recipes, but that’s such a great idea to adjust it… I didn’t even know that was possible!
Wow, that is so interesting..thanks for sharing! I have been using our small convection oven a lot lately and I like how it evenly cooks things better than our traditional oven…have an awesome day!!
Wow, thats something I never thought of checking! Great post!
Gotta get me one of these. I am quite sure my oven temp is off. The other challenge I have is that the oven doesn’t seem to hold a constant temp – the heating element goes on continuously even if I let it warm up for 30 plus minutes- so I have to watch closely to ensure the bottom doesn’t burn. Makes bakIng that much more adventurous :)
I honestly didn’t assume that it wouldn’t be correct. Woops!
I know, it’s one of those things that I never thought about either.
My oven is woefully off. After we moved in, trying to find the right temperature was an enormous pain…until we got a thermometer.
Everything comes out so much better when you actually bake at the right temperature!
Glad that things are working out for you!
Thank you, very interesting to read. I think Canadian Tire will soon have a shortage of over thermometer now you have posted this LOL.
I will have to check mine as I’m not always happy about things turn out, especially cakes.
Isa
It is soo smart to test your oven!! I still haven’t done mine, thanks for the reminder!! And your kitchen looks beautiful! :)
Thank you for sharing this! We just moved into a new house a few months ago and I cannot tell you how many recipes I have botched with the new oven. It is gas, which is new to me, and it heats up much higher than the temperatures I set it to. I am going out right now to buy an oven thermo!
goodluck!!
That is so interesting. I would never have thought to even check on something like that, because when the oven says 350 – you assume it’s 350. I’ve been married 33 years and NEVER checked my oven temp before. I will have to do that as soon as I buy a thermometer. Great blog.
Don’t worry I hadn’t checked my previous ovens either…it’s not something that comes to mind often or at all!
I’m really glad you did this experiment. Our oven growing up was always about 50F off (even when brand new), so we’d always just change where we set it. I have always used an oven thermometer to check my oven, but I kind of always wondered if my oven thermometer was trust-worthy – I’m glad to see that with 2 different ones you got accurate measurements. I also never realized that an oven could be calibrated. Huh! Will definitely look into that and consult my oven’s manual (the original owners of our house kept a binder with literally EVERY owner’s manual for everything in the house (including the smoke detectors and the blinds…??), so we even have it after 22 years!)
Also…I’m happy you pointed out that waiting some extra time and not trusting that “I’m ready!” ding is also a part of the “fudge factor” with ovens. Very helpful!
Yes, darling I am no SO very curious! I know I have this one certain cookie recipe that sure is different at my house than from my friends/families houses. I can bet you mine is way off!
Thanks Angela. :)
Have a great Friday.
It’s SO true! We move a lot so I have had a lot of experience cooking in different ovens and the differences in results and cooking times just astounds me every time! Thanks for the post as I never knew how to calibrate it.
Ugh! This explains so much. Thank you, Angela! Your blog is inspiring…still thinking about making those peanut butter cups :)
haha!! from now on, any baked treats that don’t come out right will be blamed on my new oven…teeehee. How interesting about 90 deg.! that IS a huge difference. And omygoodness Angela, I love your kitchen!! So gorgeous and bright. :D
when I was a kid, my parents bought a new custom-built home. of course, new appliances were in the kitchen. and the first meal my mom made us in that oven was burned to a crisp. if i remember correctly we had to order out for pizza because it was just not edible. my dad tried to fix it, to no avail. they had a repair man come out and he got it down to an acceptable level – we had to adjust baking time on *everything* though, even with the repair. Mom cooked/baked/roasted with that oven for well over 20 years, and just got a new oven a couple of years ago. she was so used to that dang over-heated oven that she thought something was wrong with the new one, when in fact, it was just normal!
hah great story :) funny how you get used to things over time right?
We noticed that at different settings it would even be further off. At 350 it was 380. But at 450 it was 500. Ours was awful!
I think mine was doing that too when I tried it at 425…just realized last night that it cooks stuff much quicker in the back then the front. Half my granola was burnt and half was perfect. lol
I’m pretty sure my oven’s off, have always been but am just too lazy to get a thermometer. Your post reminded me. I think I’ll just stick with increasing or decreasing the temperature as needed. The calibration thing sounds difficult!
Thanks so much for posting this. Never thought to test out an oven with an oven thermometer. So glad you posted this!!
I have used a wide variety of ovens with all my moves over the years, and I’ve found that many ovens that are 25+ years old perform better than those that are around 5-10 years. Maybe because people really used their ovens back in the day. It seems that you have to either really work at the newer models, or just shell out a lot of cash to get something decent at this point (I mean, when we moved into our 1950’s house a year or so ago, I was amazed that the huge 6 burner stove from the late 60’s was still performing superbly. . . or course, then an element died, and I couldn’t find a replacement. . .!”
you know what they say…they dont make em like they used to!!