Sous vide bags and plastic degradation/leaching?

[Anonymous Modernist 197]

Have there been any studies done on the integrity of the plastics used in sous vide bags? Do they break down under heating and/or leach into the food?

[Anonymous Modernist 10]

The polyethylene is layered in the middle, forming a composite, so it never actually touches your food. At the temperatures we use to cook food sous vide, it won't leach out. We cover this more fully in our sous vide chapter.

[Anonymous Modernist 5476]

How do I stop my bags from blowing (inflating) during cooking. For example whilst cooking oxtail for 100 hours I had to change the bag 4 times therefore resulting in the oxtail spoiling and becoming sour.

If your bags are inflating it's a good bet that you have pathogens growing. The most common causes of this is too large a piece of meat and/or too low a water temperature.

Normal sous-vide cooking should not generate gas. If the bags are fully submerged there would be no way for gas to get in even if there is a leak. In the event of a leak the water bath will cloud from the juices inside the bag, but the bag would still not inflate.

[Anonymous Modernist 10]

aidenbyrne said:

How do I stop my bags from blowing (inflating) during cooking. For example whilst cooking oxtail for 100 hours I had to change the bag 4 times therefore resulting in the oxtail spoiling and becoming sour.

What kind of bags are you using? The quality of the bag can be a factor. Otherwise, like vengroff said, the meat could have pathogens growing. You could have surface cross-contamination causing the meat to ferment.