When freezing foods for long-term storage, you want to remove as much of the surrounding air as possible. Contact with air is what can lead to freezer burn, which is why vacuum sealing your frozen foods is recommended when possible.
But what if you don't have an expensive vacuum sealer? Fear not. There's a trick that works in a pinch, and all you need is a large container, water, zip-top bags and some food to freeze.
How to seal foods airtight without a vacuum sealer
We've all tried the age-old squeeze every last bit of air out of a zip-top bag before sealing it lightning fast by hand method. But that method is flawed. Without crushing your food or releasing the bag, it's nearly impossible to get all the air out.
This trick has been used for years in the sous vide community. It replaces your writhing and squeezing with a bucket of water. Here's how it works:
- Place your food in the zip-top bag and zip the seal, leaving about 1 inch (2.5 centimeters) open.
- Find a large container, such as a storage bin, large pot or even a 1 gallon (3.8 liter) pitcher and fill it with water.
- Slowly lower the bag of food into the water, until only the corner you left open is above the water.
- Seal the remaining corner of the zip-top and remove the food from the water.
- Allow the bag to dry off completely before placing it in the freezer.
This hack uses the natural pressure of a body of water to squeeze out a lot more air than you are normally capable of by hand. It contours the zip-top bag around the food almost like a glove, leaving very little air in the bag.
Of course, this isn't quite as effective as a vacuum sealer, which sucks the air out of the bag. Some air will ultimately remain in the bag, especially if you're freezing a more solid food, such as cooked chicken or steak. Air pockets will form between the chunks of food, so you might want to jostle the food a bit while it's under water to try and squeeze out even more air.
Still, this can prolong the shelf life of frozen foods in your freezer better than the manual squeeze under your arm method can. And it doesn't crush your food to boot. And since you're filling a large container with water, it makes quite a bit of sense to seal and freeze your foods in one large batch, rather than wasting several gallons of water each time.