Freezer bags

[RubyDoo]

So I am sitting here having done all my chores, dinner is cooked and Mickthebass' tikka prepared and marinating nicely.

Pi**ing down with rain again so I thought I would ask you guys to shed some light on something that always niggles me and which I cannot find a googley answer for either.

I put food in a freezer bag  ( I use Waitrose ). Mince, chicken, and yes even liquids.  I seal the bag and ( including liquids ) there is never any leakage unless I damage the bag.

I freeze it.

I then defrost, normally putting the bag(s) in a bowl of some kind.

Why does the bag always leak liquid as it defrosts?  It is not condensation etc..  eg  mince , steaks etc will always release blood from the bag into the bowl.

Must admit I have never tried to test the integrity of the bag after defrosting by blowing in , looking for holes etc. but I know they have not been torn or damaged in the freezer.

[fried]

I have no idea.

But I do know that last month I stupidly left some chicken out to defrost on my induction forgetting the plate of course. I managed to fritz it. I thought it was done for (and me too!), luckily it started working again the next day.

[madmatt]

So I am sitting here having done all my chores, dinner is cooked and Mickthebass' tikka prepared and marinating nicely.

Pi**ing down with rain again so I thought I would ask you guys to shed some light on something that always niggles me and which I cannot find a googley answer for either.

I put food in a freezer bag  ( I use Waitrose ). Mince, chicken, and yes even liquids.  I seal the bag and ( including liquids ) there is never any leakage unless I damage the bag.

I freeze it.

I then defrost, normally putting the bag(s) in a bowl of some kind.

Why does the bag always leak liquid as it defrosts?  It is not condensation etc..  eg  mince , steaks etc will always release blood from the bag into the bowl.

Must admit I have never tried to test the integrity of the bag after defrosting by blowing in , looking for holes etc. but I know they have not been torn or damaged in the freezer.

Great question, one I would never think of posting but always swear when defrosting a bag of base and finding watery base outside the bag in the bowl I defrost it in, but with no splits in the bag.
Anyone got an answer?

[natterjak]

I put this down to abrasion of the bag whilst in the freezer. When filled with liquid, a bag has give in it. It can't really rub against anything because as soon as there is a peak of pressure pushing on any part of the bag it gives and deforms, so the pressure spreads over a wide area - hence no abrasion. But the bag is actually very very thin plastic. We forget how thin because when it deforms to spread loads it seems tough.

Different situation when the bag's contents are frozen. The bag plus contents are effectively a solid object lined with a vanishingly thin soft plastic layer.  Any rubbing, sliding, chafing etc of this plastic lined solid block can lead to tiny abrasion holes as all of the pressure of whatever force is at play are concentrated on a small area.

Even the process of freezing the bag probably thins the plastic as the contents expand while chilling.

No idea if I'm right, but that's my homespun pseudo-(not very)-scientific answer.

[Naga]

Natterjak's suggestion is supported by a couple of comments on the Discuss Cooking forum:

"I suspect that what happens is when the plastic bag with food is placed in the freezer, and the bag is sealed properly, moving the bag around in the freezer causes very, very tiny holes in the bag. Frozen foods can be very abrasive. You can even cut yourself on the sharp edge of an ice cube."

"...you Also have to remember that although the plastic Seems to be smooth it isn`t and liquids can get into those tiny grooves and pits, and since water expands 11% upon freezing, you get get tiny micro-fractures occur in the thinner parts as it stretches (or tries to)."

This explanation makes sense to me.

[loveitspicy]

Our experience even though it says safe for freezing the bags freeze brittle, so when the product inside has gone hard and the plastic on the bag has frozen, erosion holes appear and in past experience when you grab hold of the bag sometimes it just rips apart.
We freeze in boxes always

best, Rich