We all know that vacuum-sealing helps to preserve food, right? Okay, that's out of the way.
The vacuum canisters and domes ($35-$50) from NewMetro Design are great for things you want to seal but also have regular access to, like a cake or loaf of bread, or maybe that bag of whole wheat flour you're always dipping into.
The idea with these containers is that the vacuum is part of the container. Press a big button on top, and the vacuuming begins. It stops automatically when the vacuum is complete. To open the container and release the vacuum, pull the button out. The cool thing about the dome is that you don't need to use the base that comes with it, as long as you've got a smooth surface. So if you wanted to, you could put the dome over a cake plate on your smooth counter and seal the dome right onto the counter.
My first test of the dome was with a coffee cake, which I left unwrapped on a plate under the dome. The cut edge of the coffee cake didn't dry out like it would have if it were uncovered. I had the same result with a loaf of bread—the cut end didn't get dry and crusty under the dome like it would have in a plastic bag. If I had left the bread out uncovered, it would've been inedibly hard the next day. The coffee cake and bread stayed soft and tasted fresh for over a week under the dome.
The seal is so strong that I don't think a normal human could pull it open. You might be able to hammer a spatula under the rubber seal and break the seal that way, but bumping it around wouldn't do anything at all. Even after the vacuum is released, you need to tug a bit to pull up the dome.
The vacuuming isn't super-fast, but it's not like you need to watch it while it happens. The time it takes varies, but with some well-used batteries, it took over five minutes to completely vacuum the air out of the container. With fresher batteries, it was about three and a half minutes. It makes a humming/vacuuming noise when it's vacuuming, but once it's completely vacuumed it doesn't make any other sounds.
The large oval dome is pretty darned big (interior space is about 10 1/5 x 18 1/2 x 5 inches) and I'm finding it pretty darned useful. I can store a large loaf of bread in it or several smaller items.
The vacuum uses C batteries, but both the canister and dome I tested came with adapters to used AA batteries as well. Battery life seems pretty good. I accidentally left the dome vacuuming overnight while it wasn't on the base (don't ask) and it was still valiantly attempting to vacuum all the air out of the house in the morning. Those batteries are still functioning several weeks and many vacuums later.
Disclaimer: Testing samples were provided to Serious Eats.