My friend works at an artisanal brewery and he has just brought me some of the skimmings from the top of the mash tun. I asked for them because I had heard that that is the traditional way that bakers got their yeast. He just showed up unexpectedly and now I have around half a litre of the stuff and no real idea what to do with it. Any suggestions? Can I feed it with yeast like a sourdough starter? It smells lovely and beery. The beer it is from is a stout-style beer so it smells of the roasted malt so I was thinking of maybe a rye loaf? Any ideas gratefully received. Thanks!