This is not originally my idea, so I can’t claim credit for it. Some of you may have come across it on the forums and perhaps implemented it already. It’s a great idea and I figured I would share. This could also be used to experiment with different "clean" yeasts, hops, brewing processes, etc. before committing to a full batch.
Basically just add maybe a half pound or so of base malt to your mash with the intention of taking some volume from your kettle and splitting it into a gallon (or half gallon in my case since I scored some jugs and airlocks from our yeast experiment). I’ve done this two ways, pulled it off at the end of the boil/chilling and before the boil (boiling my small batch separately on my stove with a different hop schedule). Pitch some bottle dregs from a few sour beers you enjoyed while brewing and then wait and see what happens in a few months.
It requires very little extra effort or cleanup. It’s a great way to experiment and almost cost free. If you take good notes, it won’t be difficult to scale to a larger batch. The yeast/bug cake can be used as a starter for the full batch. If you fail, you only lose a dollar or two and perhaps a half hour of your time. If you succeed, you have a few good beers to drink and you can brag to your friends when you share one with them. "This is the rarest beer in the world. There were only five bottles ever produced and we are drinking one right now. Taste it. It’s goddamn glorious."