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General Science => General Science => Topic started by: neilep on 02/01/2005 13:57:53

Title: why can't you re-freeze defrozen food ?
Post by: neilep on 02/01/2005 13:57:53

Hello, I'm Neil.

I recently asked a question about why you should freeze things quickly and this is a follow up. Can you please tell me why it is strongly advised to NOT refreeze foods that have previously been frozen ?...I don't mean raw frozen food that been cooked and then frozen....I mean either raw or cooked food that has previously been frozen and then refrozen again. I don't know if I've made myself clear but hope you've got the gist of my question.

Is it just because constant refreezing destroys the structure of the meat/fish etc ?...or is it something to do with hygeine ? and that something more ' hostile ' happens to the meat during refreezing ?

Please don't take an ice-age to answer but your comments are greatly appreciated and hugged

'Men are the same as women...just inside out !'

Title: Re: why can't you re-freeze defrozen food ?
Post by: Titanscape on 02/01/2005 15:42:23

It is because meat has bacteria living on it and when it is warm the bacteria multiply. When it is frozen so are the bacteria. Frozen fresh, than defrosted, then frozen aged then defrosted means it may have had time to go off or it may have come close so that it lasts cooked for only twelve hours. But you may have forgotten.

Titanscape

Title: Re: why can't you re-freeze defrozen food ?
Post by: gsmollin on 02/01/2005 20:04:32

Freezing ruptures cell walls in the food, so afterwards it spoils more rapidly than before freezing. The bacteria in the food will multiply while it is warm, and after refreezing, it can spoil during storage.

Freezing ruptures cell walls in the food, and the taste and texture decline. Refreezing ruptures more cell walls, and the taste gets worse. Rememeber that the food is never better than fresh.

The food may have alredy been frozen once, even when sold as fresh. I'm sorry to report this fact, but I have seen it happen. So don't freeze it unnecessarily after you buy iy.

Title: Re: why can't you re-freeze defrozen food ?
Post by: neilep on 02/01/2005 21:01:26

Thanks Chaps.....your advice is well received.....I've never been tempted to re-freeze etc etc...as I know it's a big no-no....and thanks to you..I now know why...thanks again.

'Men are the same as women...just inside out !'

Title: Re: why can't you re-freeze defrozen food ?
Post by: sara_scotland on 04/01/2005 16:04:43

You also need to keep your food covered when in the freezer, because of those ice crystals.  They defrost and the water migrates to the outside of the frozen food.  If the food is not covered then the water will evaporate when defrosted, not giving it a chance to get back into the food.

Sara

Is all we see or seem, just a dream within a dream?

Title: Re: why can't you re-freeze defrozen food ?
Post by: neilep on 04/01/2005 19:48:59

Thanks Sarah...I always keep food covered in the freezer, though over time,ice crystals still form eventually unless the product is vacuum sealed eh ?....thanks, this is all facinating stuff...sometimes when I take something out the freezer and a hole has been made in the package, the product is much lighter in hue (at the hole site) and looks completely dehydrated...is this freezer burn ?

'Men are the same as women...just inside out !'