With ANY and ALL foodstuffs(which are collections of organic compounds(chemicals)) which you want to preserve, keep them away from: heat, light, extremes of pH(acid/base), oxygen, bacteria, mold, pets. Oh, and time.
Of this list, my guess is the Oxygen problem is the hardest to solve. If you have CO2(filtered CO2 from a ferm'n?) or nitrogen, slooooowly flush it with the gas from bottom up.
Now, here it is:
There exists a device called an aspirator. The old models were glass, new ones are PE and/or PP. Yes, they ARE cheap. And small, about 5' long, 2' wide, only a few oz. in weight. And nonbreakable. With no metal parts.
You hook the inlet to a regular water supply line, such as using a standard female hose fitting to which you attach the asp'r by a length of thick poly tubing or narrow garden hose. Anything, as long as you can get std. line pressure into the asp'r. It has a small side tube, aaaannnndddddd...at this side tube you will get, not water, but a near-complete VACUUM. Now, don't you think a vacuum would come in handy?
Now, you use this device at your own risk!!! I don't want any legal trouble from someone misusing their asp'r.
Where to get one? Why, the Internet!!! Good luck.