Month and half, 1L starter, made a day and half before.
Maybe it needs to warm up a bit? I have it sitting in my basement, could move it somewhere warmer.
Thanks. I would say the yeast slurry had quite a bit of dead cells. So when you made your starter, you only saw the few remaining live cells perk up and show activity while the majority of dead cells were just along for the ride. So basically this is an under-pitch situation.
Awesome guide for yeast starters. Any chance I can save this batch? Grab some new yeast and pitch? Any off flavors from initial under pitching?
Perhaps more in the interest of... testing faith that the yeasties will rise to the occasion. As they almost always do.
What's your harvest method for lager yeast? I've pulled S-04 from the mason jar at the bottom of a conical and that came out super clean.
The effects of time on stored yeast slurry are well understood and observable under a microscope and in simple forced fermentation tests. Cell vitality and viability decline noticeably over a matter of days to weeks, depending on yeast strain and many other factors, with negative consequences for fermentation therefore, potentially, the end product. It all comes down to probability. That’s what science is about really. Probability. And what the science predicts has been known, empirically, by brewers for generations. It’s even been tested unwittingly (and confirmed over and over) almost every time a home brewer directly pitches an out-of-date pack of liquid yeast. Note that these packs of yeast were prepared professionally, following best practices, to be in top condition when packaged under stringent manufacturing conditions, but the vitality and viability of cells still declines noticeably over time. It’s inevitable. That doesn’t mean your expectations aren’t met when you directly pitch a jar of 1-year-old yeast slurry, but it’s not recommended generally, because the probability of it being successful is too low. I suspect if all home brewers started directly pitching 1-year-old yeast slurry, most would be very disappointed.
I find the freshness of lager yeast cakes, including WLP833, lasts a bit longer than ale yeast cakes. I don’t think it’s just due to lower temperature either. Maybe something to do with being bottom fermenters and better adapted to survive in a slurry environment.
I get activity within several hours. By 36 hours, full-on fermentation with attenuation approaching 50% or more. Usually done the following day. Lagers take a day or two longer at 12*C. Very predictable fermentations with beers comparable my favourite commercial breweries. Nicely balanced with no off flavours. When I used to under pitch yeast and get an extended ‘lag phase’, I was a home brewer still learning the basics and not quite satisfied with the beers I was producing. I knew I could do better. So I looked at what professional brewers were doing different. They repitch loads of fresh yeast.
