Sunday Funday: Feeding Yeast on a January Evening

I hate Indian Summer when it happens. Sure, it's nice to extend the garden into September or even October. I enjoy hitting the beach after the Labor Day crowds are gone. But I like my seasons to feel like seasons, and this year, I feel that I'm missing winter.

The Mid-Atlantic has been blessed with an extremely temperate early winter so far. Aside from a freak Halloween snow storm, there's been only a few scattered snow flurries flying around these parts. It's been warm too! Temperatures seem to be running 5-10 F above typical January norms. So what does this mean in relation to a fermentation blog? I took advantage of the relatively moderate temps yesterday afternoon to feed my yeast. Hey, who am I to look a gift horse in the mouth?

I had started a culture of London Ale III yeast, a commercial Sacchromyces cervissiae strain from Wyeast Labs sold under the product number 1968. I had cultured this strain previously using a low gravity media and harvested the product of their efforts as a traditional English Mild. The flavors and characteristics of their effort seemed desirable, so I wished to perpetuate the efforts of this strain of yeast.

For this second round of fermentation, I wanted to provide a media that, when harvested, would yield a traditional stout. I put together a grain bill that would allow the yeast characteristics to express themselves while also letting the flavors of the malted barley used to prepare the media to come through. My brewing session lasted about 4.5 hours and when cooled, I added the cooled media directly to the fermenter containing the yeast from the original culture. Within 2 hours, the yeast had awakened from their slumber and were fermenting the media as evidenced by airlock activity.

Many homebrewers chronically underpitch their worts. Pitching refers to the addition of yeast to the culture media. Pitching rates indicate the number of viable yeast per given volume per amount of dissolved sugar. Optimal pitching rates depend on the amount of sugar in the media, in beer parlance called wort, and on the strain of yeast. Rules of thumb suggest that homebrewers use starter cultures to increase their cell count prior to adding the culture to wort. I'll do a future, more in-depth post on pitching rates for beer. In this case, the number of viable yeast may have actually been more than recommended, but the evidence will be in the finished product. I love active, rapid fermentations like this because it limits the opportunity for wild yeast and bacteria to populate the media.

I'm hopeful that this product will be as delicious as the last and I anticipate sharing it with friends and family around my birthday in March.