my grandfather would keep his seed in a silo over winter. And we always froze seeds if we could. Container has to be airtight. If you leave the seeds where its warm and dark they will "burn". They wont be very good plants if they grow at all.

freezing
1. airtight jars.
2. between 32-40 degrees Fahrenheit.
3. dark

Cooled
1. paper envelopes/jars/coffee cans/ etc..
2. 35-55 degrees Fahrenheit
3. dark
4. Shake the seeds once a month. (keeps them from baking themselves)

i planted corn from my grandpas old seeds and they were from 1975. Good seed right there(they were froze in old canning jars.)