I figure that keeping them stored in a cool, dark place in airtight container should be OK for a long, long time but I am ready to be corrected if someone has better info.
I would wrap my extra seeds up in a small bag or something then find a place for them to be in the fridge. this keeps them at a cool tempreture and should keep them quite healthy.
if you store seeds dry, cool and dark, they will last 3years without anything to notice, after that they start slowly to decline so that they only show a 25% chance to pop after 10 years.
i personally keep my seeds in a film container, wrapped in lil zip-locks with a dry-pack in the container. the containers i put into an old coffee tin with tight lid and down into my basement.
first, you don't vacuum seal anything, a vacuum is a totally evacuated room/space, means nothing left, okay its under pressure and no, this will not block moister nor smell totally as well
those dry packs i get in my lab, so that is probably no good source for you look into your drug bottles, like asa and that stuff, they got those in there, sometimes in the lid. dry it in the oven or microwave on damn low, don't let them get hot!! they will meld then, also don't use the Fe-powder ones they are to reduce oxygen only and can't be reactivated at all.
rice should be fine too, but it could mold... so if you can't get dry packs, go for rice, heat that rice up in the microwave until it turns light brown and backed, then the mold should be done too
rice should be fine too, but it could mold... so if you can't get dry packs, go for rice, heat that rice up in the microwave until it turns light brown and backed, then the mold should be done too