So every time we get bread it comes in a stretchy bag. However, once we pull it out of the freezer later the bag is noticeably more crinkly and brittle. Anyone know why this is? I can’t seem to find an answer to this phenomenon anywhere.
You can get stretchy bread bags?
That’s how presliced bread comes in Canada. I’m talking the sandwich loaf stuff. Not nice handmade bread.
Huh. Ours are either non-stretchy plastic bags or wax paper. You learn something new every day.
Where in Canada? I have never seen a stretchy bag in Ontario
Atlantic Canada. I don’t mean like cling wrap stretchy. It just isn’t like the crinkly kind of plastic. It has some give if you try to stretch it.
Are you meaning the instant it comes out of the freezer? Or after it’s normalized again?
It seems to stay more crinkly even after normalizing.
I’d say this is probably thermal cycling. Some polymers can degrade with repeated thermal cycling (ie tires ‘cycling out’). Google scholar has a few papers on it.
I am not familiar with the bags you are talking about (our bread bags aren’t stretchy), but this has a fairly straightforward explanation. Things that are elastic usually get stiffer when cold. This is part of why winter tires exist. There’s literally less molecular movement.
You did say they stay crinkly/brittle even after warming up, though. This is likely due to another mechanism. When a solid is created from a liquid, there is typically some type of crystal structure (with notable exceptions like glass). A material can have multiple crystal structures due to how the molecules line up. Often, the crystals are tiny, so you don’t see them, but you can have large crystals if something is cooled slowly. That’s how you get gems.
When crystals start to form, they start to incorporate as much of the surrounding material as possible. When they run into a neighboring crystal, they run out of material. Unless they just so happen to line up perfectly, they will remain separate. The space between them, called a grain boundary, can be a weak spot in something like a diamond. In metals, more grain boundaries actually make things stronger, usually. This is because metal crystals can slide along the plane of the crystal. This is why blacksmiths will quench stuff; the rapid cooling leads to smaller crystals, which leads to more grain boundaries.
A metal won’t completely form crystals from every available molecule. Every process happens over time, and cooling a metal down extra cold causes it to shrink, which can cause any straggler molecules to join up with the crystals, which makes the metal stronger. That’s why some metal objects are “cryohardened”.
The last factor is that changing temperatures can change the most energetically favorable crystal structure. Tin pest is a famous example where in really cold weather, tin can change from its useful form to a brittle crumbly useless form, and it can only be fixed by remelting it.
It’s all a bit weirder with plastics cause they can be crystalline, non crystalline, or a mix, but my guess is you’ve changed the structure of it.
Does bread in a freeze affect the texture?
A lot of packaged bread you get at grocery stores probably arrived at the store already frozen. They thaw them out before throwing on the shelf.
I’ve picked up bags at ALDIs that were still frozen.
Same is true of meats.
Unless your store always buys local, fresh foods there’s a chance it was frozen on its trip to the store.
Not in the US.
I can assure you it reaches the store warm, every morning. Local is mostly better
Happens in Aldi here in the US.
I suppose we’re talking about widely varying things. Here in Europe I think they have both pre-packaged bread and sandwich, which I suppose comes on the same truck as the other stuff. And sth like a Deli section with bread and small pizzas and stuff. That probably comes as frozen/refrigerated dough and is baked there. I’m not really sure if they do it like that at Aldi, but they do that in other stores. And I mean Aldi is just one supermarket chain.
They said not in the US, ¯_(ツ)_/¯
You dropped this: \
As far as I know Aldi and Lidl try to use their established business procedures everywhere, because it’s cheaper for them. I’ve never been to the US. But everywhere I’ve been, the stores all look very similar. I don’t know if that applies to bread, but the store layout and product assortment is similar and I bet they also use the same IT infrastructure. Including maybe ePaper price tags that arent that common in some other countries. There are some differences. Some products vary and they don’t ship them across the ocean but replace them with local products. And there are cultural differences. For example you can’t rip open the plastic wrapper and pull out one bottle of water in some countries. But I bet a lot of it is the same across the world. Especially in Europe.
Product assortment for Aldi is significantly different in North America vs Europe/Germany. But again Aldi isn’t alone in doing this, it was just an example of shipping things frozen.
It dries it out a little but it’s fine for sandwiches.
I’d say slice it first and freeze it while it’s fresh. Put it in a plastic bag and it won’t dry out noticably. However, it might get a bit limp(?) after defrosting. You can toast it slightly to make the crust crispy again. If your bread has a crispy crust in the first place. For sandwich, it’s definitely fine.
Not in the US.
I can assure you it reaches the store warm, every morning.
Break baker here. I always freeze loaves that I bake but will not be able to consume before they’d go bad sitting on the counter. After removal from the freezer and defrosting just by sitting out on the counter, I find no difference between the frozen loaves and not frozen. It’s a great way to preserve bread for future consumption if you’re making multiple loaves at once.