Do these really work? I imagine the machines with the whole plastic bag getting the air sucked out of them are the best. More specifically, I'm wondering about those simpler ones with a button on the lid which, when pressed, engages a vacuum seal.

Or are these all just a complete waste of money?

 

I think it would create a light vacuum seal, but that is only to SEAL the lid on the container. Since not much of a vacuum is actually created there is still a fair amount of air in the container. A FoodSaver is the real deal and they work like a charm. I use mine all the time and buy things in bulk then seal them in the bags and freeze them. It works great.

 

it will work the same way a air tight container does. great for coffee and other dry goods that need to stay air tight for freshness. it may extend it a bit because of the small "vacuum" it generates, but i can't see it extending the shelf life for weeks. anything that you need to extend for that kind of shelf life should be completely vacuum sealed anyway. can't really see using them unless the are the same price or cheaper than standard air tight containers.