I’ve been making a lot of yeast starters lately. I’m slowly building up a fair sized yeast bank. WhenÂ you pitch a yeast starter directly into the wort, you want to do it when all the yeast is still in suspension and the yeast is actively fermenting. But when I’m just stepping up a yeast so that I can put it in a mason jar and store it for future use, I usually ferment it all the way out, so the yeast drops out and the beer above is clear. I pour off that liquid and swirl the yeast around, then dump it in a sanitized jar, cap it and store it in the fridge.
But what to do with that beer you pour off, do you just dump it? Lately, I’ve been tasting it and learning a lot about the contribution of yeasts to particular beer styles. This beer has no hops in it, itÂ is low in alcohol and has very little maltiness. So what you taste is just the yeast, or more accurately, the characteristics of the yeast. For instance, with a British ale yeast such as Wyeast 1968 (London ale yeast) you get a sweet finish, fairly fruity and noticeable diacetyl. Rather than just tasting a British ale and trying to find these characteristics through all the hops and malt and CO2, you can get a really good feel for this by just tasting the beer left over from a starter. Or if you have Wyeast 1056 (American ale) you get a clean, crisp flavour profile, without a lot of esters, diacetyl or fruitiness. With wheat and Belgian beers, you get the banana esters, phenols and clove like chracteristics.
You probably won’t want to drink a whole glass of this stuff. It’s not nearly as enjoyable as a real beer, but it can be educational.