Why does meat leak blood through a sealed bag?

[pacanis]

Got a question; Why is it that frozen meat left to thaw in a ziploc bag will let the blood leak through? I had thought it might have something to do with contracting and expanding, at least the way I stuff a bag and try to get the air out (pre my Foodsaver), but I just thawed a small amount of burger in a large bag that was open/had not been sealed tight and it still leaked though the bag.
Why is that?

 

[Uncle Bob]

The blood either leaked through the unzipped opening, or the bag has a hole in it maybe?

 

[StirBlue]

Sealed chicken and turkey does the same thing. I just put it in a container in the refrigerator. When I buy it at the grocery store, I put it in the plastic bags that they have on rolls over the counter.

 

[pacanis]

It's not like I don't take precautions.... I just don't understand why this happens. Why does freezing plastic bags, even freezer bags, seem to breakdown their "virtually leakproof" capabilities?

 

[Half Baked]

That's a great question for their customer service link in your brand's website. Why don't you send them a note? I'd love to know the answer.

 

[Katie H]

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.

I would suggest that after you've removed the food from the bag, you fill it full of water and hold it up over the kitchen sink to see if it has been breached.

 

[sparrowgrass]

I think Katie has the right answer. I know stuff in my chest freezer gets knocked around a bit, and I think that makes holes in the bags.

I always defrost stuff on a plate or pan.

 

[pacanis]

Ya know.... I'll bet that's it, too, now that you mention it

I was told by several people that leaving those inflatable plastic lawn ornaments (so popular with my neighbors at Christmas time ) inflated all the time is better for them than deflating during the day and reinflating at night because of the freezing temperature's affect on plastic and the crinkling/stretching they go through. Same difference I'll bet moving around a 0 degree plastic bag in the freezer. That plastic has to take some abuse.
Ahhh, I can sleep at night again Thanks

 

[YT2095]

Katie E is on the money, 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).