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In one oven I need to bake 2 dishes: one needs 35 minutes at 375ºF, and the other needs 45 minutes at 350ºF. How much time should the second dish cook at 375ºF?

Luciano
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Neal
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  • Perhaps put "slightly different" temps in the title so it's clear that it's close enough to consider a half-way temperature or cooking one or the other at a different temp. – Peter Cordes Feb 14 '20 at 08:05
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    What dishes ? it can help us help you. – Max Feb 14 '20 at 11:59
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    Stews versus cakes will make a huge difference in the answer. Your boeuf bourguignon will not care, but the choux à la crème will care. Which one is it? – Jeffrey Feb 14 '20 at 13:35
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    The duplicate-sounding question actually has some very different temperatures - 350 vs. 475 F. In that sense, 350 vs. 375 are practically the same temp, so this is a different question, not a duplicate. However, to get an accurate answer, you really need to detail what sort of dishes we're talking about. – Marti Feb 14 '20 at 16:24
  • @Marti: Agreed; someone with more rep than me should edit the other one have a more specific title (mention meat vs. roasted veggies for example). These questions aren't as generic as their original titles hoped or implied.. – Peter Cordes Feb 14 '20 at 16:36
  • @moscafj I disagree that it's a dup. The closeness of the temperatures means it requires a different answer from the linked one. – FuzzyChef Feb 14 '20 at 21:15
  • There are several "two dishes..different temperature..needed at same time" - type of questions on the site. I guess we either ask and answer each one, or have some type of general response. – moscafj Feb 15 '20 at 16:10
  • Well, there's two basic cases: when the temps are far apart (325/450) vs. when the temps are close (325/350). We could create an artificial canonical question for this one ... do you wanna ask, or answer? – FuzzyChef Feb 18 '20 at 04:56
  • Wait, I think I found our canonical answer. The asker didn't accept it though; can you fix that? https://cooking.stackexchange.com/questions/57094/cooking-multiple-dishes-at-once-in-the-oven?noredirect=1&lq=1 – FuzzyChef Feb 18 '20 at 04:59
  • @FuzzyChef I'm not a moderator, so I don't think there is anything I can do. I did see your post on meta. I think the Q&A you found is the right way to handle this particular type of question. I'll upvote the answer in that question, beyond that let me know if there is anything else I can do. – moscafj Feb 18 '20 at 21:50
  • @moscafj ah! I thought you were. – FuzzyChef Feb 19 '20 at 00:07

2 Answers2

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On a practical basis? 40 to 45 min. That is, bake it for 40 min and then check it to see if it's done (or otherwise check it 5 minutes earlier than you otherwise would).

The difference between 350F and 375F in actual cooking is generally dwarfed by the temperature inaccuracy of home ovens.

FuzzyChef
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    Also, as part of their temperature inaccuracy, most ovens have some positions hotter than others — usually the top and back are hotter, in my experience — so putting the dish that wants 375º in the slightly hotter part of the oven and the dish that wants 350º in the cooler part will help. – PLL Feb 14 '20 at 10:25
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    I'd suggest exactly that too @PLL, the lower part of the oven is often cooler, especially in a non-fan oven, I'd put the cooler dish there and cook it for the same amount of time. – GdD Feb 14 '20 at 11:09
  • would splitting the difference and cooking at 365 be advisable, or is there really 25F diff in position? – dandavis Feb 14 '20 at 16:41
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    I think your answer is correct and I've upvoted it, but it's also started me wondering if there's any reference to cite for your last sentence about the accuracy of home ovens. Is there any actual data available showing average accuracies or anything? – dwizum Feb 14 '20 at 20:25
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    @dwizum why, yes, there are! I'll add a link, but here's some for you: https://www.reviewed.com/ovens/features/why-oven-temperatures-are-inexact https://blog.thermoworks.com/thermometer/thermal-secrets-oven-calibration/ – FuzzyChef Feb 14 '20 at 21:10
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To be honest, your probably don't even need to worry about the slightly different timing and temperatures.

I'm not a temperature expert but, I'm relatively sure that Fahrenheit should be converted to Kelvin to calculate the specific difference between two temperatures. 25F sounds like a big difference but it really isn't.

350f = 449.817 kelvin
375f = 463.706 kelvin

Then we can compare the values:
449.817/463.706 = 0.97

This shows us there's a 3% actual difference.
If you wanted to figure out the precise timing (but i assure you it won't matter) - you'd calculate 97% of the longer time which ends up being 43 minutes and 39 seconds.
I'm fairly sure if 1 minute and 21 seconds longer is going to ruin your dish - you're doing something else wrong.

Delarius
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    The rate of heat transfer into the mass being heated depends on its initial temperature, which is most likely not 0 Kelvin. – The Photon Feb 14 '20 at 00:20
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    Yep, using the boiling temperature of water (instead of 0K) would be a more sound comparison – Jeffrey Feb 14 '20 at 13:37
  • Absolute temperature would be relevant if this was heat transfer by radiation, but I doubt that that's an important process when baking food in an oven. –  Feb 14 '20 at 15:07
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    @BenCrowell I doubt K are the right units to think about, but you're certainly incorrect about radiative heat transfer in an oven. It's very important and possibly the dominant mechanism. See, for example, https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1365-2621.1974.tb02872.x – Xerxes Feb 14 '20 at 15:56
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    Changing the units then making a comparison by the new units is less than useful. Sort of like converting feet into astronomical unit (AU), then saying that a difference between two lengths isn't even a whole percentage of an AU, so it's not very far. – computercarguy Feb 14 '20 at 17:55
  • @computercarguy I'm not saying this method is useful, but it's not comparing the difference to the unit, it's comparing the two temperatures to each other. For lengths, the ratio should be the same regardless of the unit used, since 0 length is always no length. Temps are different since a temp of 0 isn't necessarily a complete lack of heat. – Kat Feb 14 '20 at 21:56