2020 Seed Swap Circles

Is it recommended we do a random sample viability test on all we save?  i.e. do I sow a couple of everything I've saved to see if it grows?

No I don't bother. We are friends. Everything is saved in the hope that it's viable - if it isn't we haven't lost anything. 
One year i sent every one globe thistle/Echinopes seed. None came ? I was really surprised but no one really minded. It's just one pot and not much time wasted?

Phew!  That's a relief.  I'll try to check any seed I have a doubt about.  When saving tomato seed, what would happen, do you think, if I happened to leave the seeds to ferment a little longer than the three or four days. Would they still be worth saving? I forgot about some and the seeds have dried rather dark.  I've sown a couple to see what happens, so I'll probably be able to answer my own question.