I have a glass baking dish my husband put together a meatloaf in it last night and put it in the fridge. Can I put it right in the hot oven? I think no so I have had it sitting on the kitchen table most of the dish is warmer but the bottom is still a little cold not as cold as it was but cold. I'm scared to put it in there. I have no idea who it's made by.
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4 Answers
It would depend on the type of glass.
If the oven is say 300 F then starting from 40 F (fridge) versus 70 F (room) is not a big difference.
If the glass is oven safe then that 30 F difference should not cause failure.
70 F to 375 F is a bigger difference than 40 F to 300 F.
answered Jan 12, 2018 at 17:39
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1Thanks for running the numbers. I didn't have time and would have done it in Celsius anyway. +1– Chris HJan 12, 2018 at 17:55
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5Thermal breakage of glass and similar bake ware normally is far more common with cooling rather than heating as the applied temperature stress is much faster. That is dumping a hot dish into cold water is much more likely to be an issue that putting a cold one into the oven. The oven is a more gradual heating even when pre-heated. As long as it is an oven safe dish, this answer should be accurate. It is not as if you are putting onto a pizza stone or iron heated to 550+, I hope.– dlbJan 12, 2018 at 21:25
Mine are (British/European) PYREX, which is borosilicate and has better thermal properties than US soda-lime pyrex.
It would almost certainly be OK, but to be on the safe side I'd put it on a room temperature baking sheet (ideally quite a thick one) before putting it in the oven. This will avoid the thermal stress caused by the bars of the shelf. Note that the difference between room temperature and fridge temperature is smaller than the difference between the coolest and hottest ovens you'd cook in.
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6(1) The rack and dish are not going to be absolutely flat. So there will be stresses in the dish due to uneven contact. The pan will just even that out some since it has a thermal mass which will slow the heating of the dish. (2) Also a larger flat surface minimizes local hot spots since metal is a much better heat conductor than glass.– MaxWJan 12, 2018 at 17:15
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7@NuclearWang my reading of the Q is that the OP is worried about the dish cracking due to thermal stress (which MaxW has described). The baking sheet won't just act as a heat spreader but will slow the rise in temperature a little.– Chris HJan 12, 2018 at 17:31
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2Also have to remember that used glass dishes have scratches. Such scratches will weaker the glass. // My notion is that a baking sheet isn't going to make a gigantic difference. But it is something and it would be at least slightly helpful. It is all that one could reasonably do to lessen the stress on the glass dish.– MaxWJan 12, 2018 at 19:55
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2I've moved a lot of discussion to chat. If you'd like to continue discussing, please focus on the subject at hand.– Cascabel ♦Jan 12, 2018 at 21:36
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1A google search reveals claims (e.g., on Wikipedia) that not all kitchen Pyrex-brand glassware is borosilicate anymore. So if you really want the borosilicate performance you might have to move to laboratory equipment - perhaps these petri dishes would suffice for baking or roasting something small. Covers are available too. But they're rather pricey ...– davidbakJan 13, 2018 at 6:40
It is impossible to answer this question without knowledge of the exact material and temperatures. Perhaps it is made of Pyrex.
The glass will break, if the thermal expansion is not homogeneous and causes high stress. Modern glass and glass ceramics minimize the thermal expansion coefficient a(T). This coefficient changes with the temperature so you can not assume that the effect is the same, if the temperature difference is the same.
The stress is maximized at the fill line, if your glass is heated up on the top, but still cold on the bottom, where the wet food with high heat capacity is.
Say the temperatures are
fridge T_f = 7 °C = 266 K
room T_r = 17 °C = 290 K
oven T_o = 350 °C = 625 K
Q: If the glass can resist the stress of dT_1 = T_o - T_r = 335 K, will it likely resist dT_2 = T_o - T_f = 345 K?
The data sheets of glass ceramics show usually little difference for 10 K variation. You want to lookup a(T_f) and a(T_r).
I expect, that the glass ceramic will withstand heating up from T_f to T_o. A nearly full or nearly empty dish has a constant inner temperature and will withstand a higher temperature difference than a half filled dish.
Bonus: Schott is one manufacturer of glass ceramics and you can look up data sheets on their website, but also view this impressive movie about NEXTREMA glass ceramics while you are waiting for the meal. Thermal shock resistance of SCHOTT NEXTREMA® glass-ceramics
Some discussed °C/°F here, but in this question neither Fahrenheit nor Celsius but Kelvin is the correct temperature unit if you want to do any calculations.
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C and K difference is the same. What makes F an invalid temperature for calculation? Jan 15, 2018 at 0:48
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@Paparazzi Kelvin describes the temperature in a physical sense and it is a bad advice to use a different unit for physical properties. But you are of course right that the Kelvin unit is just a Celsius with an offset. It is very complicate and error prone to use F or C for calculations. Jan 15, 2018 at 4:19
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How about placing your meatloaf in a 'bain marie' - another larger dish, containing warm water? That way, your glass dish can gently adjust to a warmer temperature. I would let it sit til the glass dish no longer feels cold, (change the water to warm again, a few times if necessary - til your glass dish is slightly warmed) then why not put the whole thing in the oven, like that, bain marie and all? I think this will protect your dish quite well. Good luck!
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Er what's with marking down my perfectly helpful comment without saying why? So obsessed measuring temperature that you can't even try a practical suggestion? That works - I use this a lot in both directions cold to hot and hot to cold. If I want to put something still warm in the fridge (as I cant just leave it out because I live in a hot climate and it will go off right away) I put it in a bain marie of ice water, chill it quickly and put in the fridge. Works well.– JelilaJan 25, 2018 at 2:29