# Does glass bakeware need to be seasoned? **URL:** \ **Category:** Cafe Society\ **Created:** [March 12, 2020, 4:36am UTC](https://boards.straightdope.com/t/does-glass-bakeware-need-to-be-seasoned/849316 "2020-03-12T04:36:17Z")\ **Posts on this page:** 14\ **Page:** 1
**Author:** ![lissener](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lissener/32/6139_2.png) [@lissener](https://boards.straightdope.com/u/lissener)\ **Post date:** [March 12, 2020, 4:36am UTC](https://boards.straightdope.com/t/does-glass-bakeware-need-to-be-seasoned/849316/1 "2020-03-12T04:36:17Z")
I’ve been baking my own bread recently. I have two old glass breadpans: one hand me down, one resale. The baked bread just falls out of them, zero resistance. My sister bought me a third, new, so I would bake some for her too. So I just pulled all three out of the oven. The two old ones released the bread smoothly and immediately. The new one, the bread is like baked in, like epoxy. Absoutely impossible to remove in one piece. Is it the age that makes a difference? I mean, I wouldn’t think so because glass is inert, right? Any help on this? ---
**Author:** ![Roderick\_Femm](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/roderick_femm/32/14875_2.png) [@Roderick\_Femm](https://boards.straightdope.com/u/Roderick_Femm)\ **Post date:** [March 12, 2020, 4:43am UTC](https://boards.straightdope.com/t/does-glass-bakeware-need-to-be-seasoned/849316/2 "2020-03-12T04:43:46Z")
Checking to make sure this isn’t GQ. Ok, I’m going to speculate. First, I’m pretty sure glass is not inert in the sense of unchanging, but it is largely unreactive to chemicals. I don’t know why. I’m also surprised that any glass baking dish would ever release baked goods without butter or oil or something. My second thought is that it’s possible that the formula for glass bakeware has changed, or that different companies have different formulas (you didn’t say if the new pan was the same brand as the old ones). Thirdly, this sounds like a great question for the folks at America’s Test Kitchen who deal with cookware. But it might take a while to get an answer, so in the meantime, I’d butter and flour it or line it with parchment paper. ---
**Author:** ![lissener](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lissener/32/6139_2.png) [@lissener](https://boards.straightdope.com/u/lissener)\ **Post date:** [March 12, 2020, 4:59am UTC](https://boards.straightdope.com/t/does-glass-bakeware-need-to-be-seasoned/849316/3 "2020-03-12T04:59:48Z")
Yes of course I know the workarounds. I’m just trying to figure out what’s going on ---
**Author:** ![wolfman](https://avatars.discourse-cdn.com/v4/letter/w/a8b319/32.png) [@wolfman](https://boards.straightdope.com/u/wolfman)\ **Post date:** [March 12, 2020, 6:00am UTC](https://boards.straightdope.com/t/does-glass-bakeware-need-to-be-seasoned/849316/4 "2020-03-12T06:00:15Z")
Are the old ones Pyrex(Borosylicate glass) as opposed to pyrex or Anchor Hocking( soda lime glass)? ---
**Author:** ![Chronos](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/chronos/32/134_2.png) [@Chronos](https://boards.straightdope.com/u/Chronos)\ **Post date:** [March 12, 2020, 11:16am UTC](https://boards.straightdope.com/t/does-glass-bakeware-need-to-be-seasoned/849316/5 "2020-03-12T11:16:22Z")
Pyrex as opposed to pyrex? ---
**Author:** ![kanicbird](https://avatars.discourse-cdn.com/v4/letter/k/5f8ce5/32.png) [@kanicbird](https://boards.straightdope.com/u/kanicbird)\ **Post date:** [March 12, 2020, 11:19am UTC](https://boards.straightdope.com/t/does-glass-bakeware-need-to-be-seasoned/849316/6 "2020-03-12T11:19:58Z")
The recipe for Pyrex has changed. As usual the old stuff was great and the new stuff is crap (and could shatter). > **[Pyrex Isn't Therma Shock Proof Anymore and Here's What You Need to Know](https://www.wideopencountry.com/pyrex-isnt-thermal-shock-proof-anymore-and-heres-what-you-need-to-know/)** > > The Pyrex thermal shock proof glassware we've known for years has actually changed its type of glass, meaning it could shatter with temperature changes. ---
**Author:** ![purplehorseshoe](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/purplehorseshoe/32/2996_2.png) [@purplehorseshoe](https://boards.straightdope.com/u/purplehorseshoe)\ **Post date:** [March 12, 2020, 11:33am UTC](https://boards.straightdope.com/t/does-glass-bakeware-need-to-be-seasoned/849316/7 "2020-03-12T11:33:07Z")
Does the new formula have different thermal expansion/contraction? That could explain the release, if the glass “squeezes” out the contents ever so slightly. Another difference between old and new glassware is wear … scratches etched into the surface. Although, I would guess a scratched up surface would be less likely to release, not more, so that can’t possibly be the issue here. So, uh, scratch that last part. ---
**Author:** ![lissener](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lissener/32/6139_2.png) [@lissener](https://boards.straightdope.com/u/lissener)\ **Post date:** [March 12, 2020, 6:07pm UTC](https://boards.straightdope.com/t/does-glass-bakeware-need-to-be-seasoned/849316/8 "2020-03-12T18:07:46Z")
> [@kanicbird](#): > > The recipe for Pyrex has changed. As usual the old stuff was great and the new stuff is crap (and could shatter). > > [Pyrex Isn't Thermal-Shock Proof Anymore: Here's What You Should Know](https://www.wideopencountry.com/pyrex-isnt-thermal-shock-proof-anymore-and-heres-what-you-need-to-know/) Thank you! This has to be it. ---
**Author:** ![lissener](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lissener/32/6139_2.png) [@lissener](https://boards.straightdope.com/u/lissener)\ **Post date:** [March 12, 2020, 6:09pm UTC](https://boards.straightdope.com/t/does-glass-bakeware-need-to-be-seasoned/849316/9 "2020-03-12T18:09:21Z")
> [@Roderick\_Femm](#): > > My second thought is that it’s possible that the formula for glass bakeware has changed, or that different companies have different formulas (you didn’t say if the new pan was the same brand as the old ones). New one is Pyrex, but so is one of the old ones. The other oldie just has a W on the bottom. ---
**Author:** ![AlsoNamedBort](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/alsonamedbort/32/3213_2.png) [@AlsoNamedBort](https://boards.straightdope.com/u/AlsoNamedBort)\ **Post date:** [March 12, 2020, 6:18pm UTC](https://boards.straightdope.com/t/does-glass-bakeware-need-to-be-seasoned/849316/10 "2020-03-12T18:18:24Z")
> [@purplehorseshoe](#): > > Does the new formula have different thermal expansion/contraction? That could explain the release, if the glass “squeezes” out the contents ever so slightly. > > Another difference between old and new glassware is wear … scratches etched into the surface. > > Although, I would guess a scratched up surface would be less likely to release, not more, so that can’t possibly be the issue here. So, uh, scratch that last part. I’d also wonder about heat transfer rate. One cake could be more or less baked on the bottom, which would affect how it sticks. ---
**Author:** ![lissener](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lissener/32/6139_2.png) [@lissener](https://boards.straightdope.com/u/lissener)\ **Post date:** [March 12, 2020, 7:22pm UTC](https://boards.straightdope.com/t/does-glass-bakeware-need-to-be-seasoned/849316/11 "2020-03-12T19:22:34Z")
> [@lissener](#): > > New one is Pyrex, but so is one of the old ones. The other oldie just has a W on the bottom. It’s likely the W stands for Westinghouse ---
**Author:** ![lissener](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/lissener/32/6139_2.png) [@lissener](https://boards.straightdope.com/u/lissener)\ **Post date:** [March 12, 2020, 7:35pm UTC](https://boards.straightdope.com/t/does-glass-bakeware-need-to-be-seasoned/849316/12 "2020-03-12T19:35:05Z")
Turns out OXO uses borosilicate. Might have to buy one of those, use the new Pyrex for things that DO need a greased pan, like quickbreads and casseroles. ---
**Author:** ![wolfman](https://avatars.discourse-cdn.com/v4/letter/w/a8b319/32.png) [@wolfman](https://boards.straightdope.com/u/wolfman)\ **Post date:** [March 13, 2020, 1:49am UTC](https://boards.straightdope.com/t/does-glass-bakeware-need-to-be-seasoned/849316/13 "2020-03-13T01:49:54Z")
> [@Chronos](#): > > Pyrex as opposed to pyrex? It was supposed to say PYREX vs pyrex, but I missed the fact my browser cleaned it up. They changed to lower case name for the new stuff. ---
**Author:** ![Yorkshire\_Pudding](https://avatars.discourse-cdn.com/v4/letter/y/59ef9b/32.png) [@Yorkshire\_Pudding](https://boards.straightdope.com/u/Yorkshire_Pudding)\ **Post date:** [March 13, 2020, 9:39am UTC](https://boards.straightdope.com/t/does-glass-bakeware-need-to-be-seasoned/849316/14 "2020-03-13T09:39:52Z")
Could be years of seasoning, despite the instinct that glass doesn’t need it or accept it. I know glass cleans up well, but after years of use, some of my glass bakeware appears to have a subtle film on the surface. The subtle film is maybe significant? I’ve never tried baking bread in glass, incidentally. Is there a significant advantage over metal, do you find?