Seal food airtight --- without a vacuum sealer machine!

You know that the vacuum packing method of preserving food helps to  prevent contamination via dust and microbes but you do not have access to a special vacuum packaging machine?

No problem! All you have to do is place the food that you intend to preserve in a plastic bag with a zipper lock, close it leaving the last part of the zipper lock open, and slowly lower the plastic bag into a container filled with water.

Continue lowering the plastic bag until the water level reaches (but does not exceed!) the corner left open and then close the zipper lock. Now you are done!