Naked Science Forum

General Science => General Science => Topic started by: podcastmaker on 15/10/2020 09:50:41

Title: Why Does Bread Go Off Quicker In The Fridge ?
Post by: podcastmaker on 15/10/2020 09:50:41
Why Does Bread Go Off Quicker In The Fridge ?
Title: Re: Why Does Bread Go Off Quicker In The Fridge ?
Post by: evan_au on 15/10/2020 10:08:34
I don't think it does.

Cooler temperatures near 4°C tend to slow down most microbes.

Maybe your fridge is not operating close to 4°C (maybe it needs a defrost cycle, or the refrigerant gas has leaked out, or the door seals have perished?), or maybe your fridge is full of fungus spores?
- Putting food in the fridge promptly after you buy it helps.
- Keeping it in its own bag probably also helps.
- And buying food that is not near its use-by date also helps.
Title: Re: Why Does Bread Go Off Quicker In The Fridge ?
Post by: Bored chemist on 15/10/2020 10:16:14
Define "go off".
Microbiological  growth is slowed, but there are changes in the structure of the proteins that are faster in the fridge.
It goes "stale".
Title: Re: Why Does Bread Go Off Quicker In The Fridge ?
Post by: alancalverd on 15/10/2020 13:49:57
Unwrapped or poorly wrapped bread will lose moisture in a refrigerator. Wrapped bread keeps well in a freezer but the texture can suffer by slow thawing: "toast from frozen" seems to work best. 
Title: Re: Why Does Bread Go Off Quicker In The Fridge ?
Post by: Bored chemist on 15/10/2020 14:58:43
It's not just a matter of "drying out".
"THE STALING PROCESS
When bread goes stale, it just looks all dried out, but there is more going on there than just moisture loss. Processes of retrogradation and recrystallization of starch are occurring. In short, there is a change in the structure of the starch molecules and they begin to crystallize once the bread is removed from the oven. The crystallization forces water out of the bread and staling occurs. In addition, the exposure to air also promotes moisture loss."

From
http://www.breadsense.com/news/2016/9/9/mythbuster-keepin-it-fresh
Title: Re: Why Does Bread Go Off Quicker In The Fridge ?
Post by: alancalverd on 16/10/2020 11:26:06
Ignoring this can cause annoyance at home and problems in industry. Slicing very fresh homemade bread can end up with most of it stuck to the knife, and I recall working in a craft bakery (it was just called a bakery in those days!) in 1960 when we only sliced loaves that were at least 2 hours out of the oven. Not sure what they do with modern "industrial" bread, but in-store bakers aren't keen to slice anything too warm. Do Warburtons use lasers, wait for a day, or tweak the chemistry to speed the setting?   
Title: Re: Why Does Bread Go Off Quicker In The Fridge ?
Post by: Bored chemist on 16/10/2020 11:45:54
wait for a day,
If your loaf takes a day to cool, it's a bit too big for most people.
Title: Re: Why Does Bread Go Off Quicker In The Fridge ?
Post by: Colin2B on 16/10/2020 16:05:20
Not sure what they do with modern "industrial" bread, but in-store bakers aren't keen to slice anything too warm. Do Warburtons use lasers, wait for a day, or tweak the chemistry to speed the setting?   
It goes through a forced cooling to get the internal temp down to between 32°-42°C, this also allows moisture to move outwards and soften the crust.
Title: Re: Why Does Bread Go Off Quicker In The Fridge ?
Post by: alancalverd on 16/10/2020 16:29:46
How dull! Lasers would be a lot more fun!
Title: Re: Why Does Bread Go Off Quicker In The Fridge ?
Post by: Bored chemist on 16/10/2020 17:50:07
How dull! Lasers would be a lot more fun!
Title: Re: Why Does Bread Go Off Quicker In The Fridge ?
Post by: Colin2B on 16/10/2020 17:53:13
How dull! Lasers would be a lot more fun!
Pretoasted?