On a trip to the Grand Canyon I noticed that pretzel bags, yogurt bottles and everything that is vacuum packed tended to swell due to the lower air pressure outside. I did not see that products sold in the area had this effect, and I was wondering – do the companies produce the product with different internal pressure depending on the destination it is sold? That sounds too expensive.
There was no change in the swelling of my pretzel bags after a week in high altitude, so I don’t think the pressure equalizes after a while – at least not a short while.
Any ideas?
On a trip to the Grand Canyon I noticed that pretzel bags, yogurt bottles and everything that is vacuum packed tended to swell due to the lower air pressure outside. I did not see that products sold in the area had this effect, and I was wondering – do the companies produce the product with different internal pressure depending on the destination it is sold? That sounds too expensive.
There was no change in the swelling of my pretzel bags after a week in high altitude, so I don’t think the pressure equalizes after a while – at least not a short while.
Any ideas?
PS: I have just received an answer that the products are packaged locally. I find that difficult to believe – the grand canyon for example is remote and small. I don’t think it’s economically feasible to do the packaging there.
I have just received an answer suggesting that the products are packaged locally. I find that difficult to believe – the grand canyon for example is remote and small. I don’t think it’s economically feasible to do the packaging there.
They will have been manufactured, or at least packaged, locally so the pressure in the bag is equal to local pressure.
I’m not sure! We were on a trip to the mountains in Colorado also and as we were going up some of our stuff popped! Scared the poo out of us! There were a few things that popped before we knew what was going on! It was scarry at the time, but hilarious later! I have always wondered the same thing! Maybe there is something in the truck that helps with the vacume when they are shipping or something?
Aluminized Mylar film will contain air pressure for months and longer. One therefore uses Occam’s razor and,
1) They were packaged locally, or in Denver; or
2) One very tiny pinhole/film package added.
Helium fill and diffusive depressurization would be both expensive and still slow. Did you look on the package for where they were created?
The local packaging answer is the right one.
Products sold in the Grand Canyon would mainly be packaged in Las Vegas, at roughly the same elevation.
If you go shopping in the high rockies, where most of the products are packaged at 5000 feet lower elevation in Denver, you will notice that the chip bags do in fact bulge with the pressure when sitting on the shelves.