I am a plumbing contractor. I have had the pleasure of working at a local brew pub for the past few years. I often take a portion of my profits in beer/food/merch. Inevitably I have made friends with the brewer.
So I recently asked him for some yeast. He said sure, "bring me a growler tomorrow, I'll give ya plenty". I dropped off the growler , and picked it up the day after that (going to the brew pub 3 days in a row is real chore). When I picked it up he said "I put some beer on top to keep it fresh".
I brewed an IPA the following day. I should have used a blow off. Within 12 hours the airlock was full of Krausen and such. I had plenty of yeast left and decided to just put it back in the growler with the beer the brewer had given me back on top of it.
Two weeks later I am getting ready to brew a Porter. I bought a vile of WLP002 but didn't make the starter so I thought "eff it, I'll just use that yeast Mark gave me." I cracked the growler open and to my delight, I hear a powerful "psssssssssssssssshhhh". The beer had carbed in the fridge over the 2 weeks.
It was actually a bit over carbed. There was enough for two full glasses. I don't think anything tastes better than free, fresh beer.
Hot on left, cold on right, $^*t rolls downhill, and paydays on Friday. You're now an apprentice plumber.