Hey all. I brewed 10 gal of Octoberfest on Saturday and pitched approx 350 mL of WLP830 slurry from my last batch of lager into each fermenter. It has been 36 hours so far and there is no activity. The temp is at 50°F. Am I being impatient? Should I wait a bit longer or pitch more yeast? I have 2 packets of Saflager 34/70 that I could use. Any thoughts?
Cheers,
Brandon
That is a long time to wait. Buckets or Glass?
Did you add any yeast nutrient to the boil? When repitching slurries, they really need that extra boost to get going well (especially lager yeast).
Buckets. Yes, I added yeast nutrients. I like the extra insurance from the nutrients even if it’s not necessary.
Buckets are notorious for not always sealing well. I’d open for a quick peek - if there’s krausen head, the lid didn’t seal well. If not, you could pitch some 34/70 and also get the chance to re-seat the lid for (maybe) a better seal.
That’s what I was thinking this morning. I opened one of the buckets. There wasn’t any krausen. I’ll have to check on them tonight after work.
What about aeration? I pumped the wort into the buckets and kept the hose high enough to create some foam. But, I didn’t use a mix stir for additional aeration.
Repitched slurries are notoriously in need of lots of fresh O2 to help build sterols and keep their cell membranes pliable for growth and reproduction. Have you had issues with your aeration procedures prior to this regarding slurry repitches or cold fermented lagers in general?
How old was your saved slurry?
350 ml seems like a small pitch for 10 gallons. I think you may need to give the yeast extra time because of that.
Mr. Malty says you need 750 ml of its default slurry for 10 gallons of 1050 beer. I am not sure of your gravity so I guessed 1050.
If you pitched 350ml of slurry into each vessel and each has five gallons of beer then you might have pitched sufficient volumes–if the slurry was fairly fresh. Pitching rate calculators tend to assume viability nosedives relatively quickly. If the yeast was a couple weeks old it was probably enough but if it was a couple months old (and I mean from the end of primary fermentation from the harvested batch) then you may have underpitched by 50% or more.
Personally I’d pitch the 34/70 and get fermentation going rather than keep waiting and seeing what happens.
I’m thinking you under aerated also. At this point, I guess I’d warm it up to at least 55F. Not sure about aerating at this point…maybe it’s a good idea?
Yep, I pitched 350mL into 5 gal of wort. The 10 gal batch was split into 2 fermenters. The OG was 1.055 so you guessed very close.
I’ve used that method with ales before with no issues. I had transferred the beer off the yeast 2 days prior to repitching it. The beer was in the fermenter for approx 3 weeks. Perhaps I didn’t aerate well enough
I just did a 1.064 brew with Kolsch yeast at 64F. I forgot to do my starter so I ended up just dumping 2 smack packs into 5.5G and oxygenated it well. The surface looked like glass at 36 hours, but by 42 hours I saw some bubbles and by 48 a nice thick head of foam was building.
Yeast under less than ideal conditions will take some time, but it should do something. Complete failure to launch seems unlikely with that much fresh slurry.
To the earlier point about oxygenation, if you’re aerating lagers with a “high pressure foaming transfer”, it does seem like repitching could be problematic as the sterols continue to be depleted across generations.
Have you had success repitching lager yeast this way before or is this a relatively new process for you?
Sorry - overlapping posts.
Yes, in my experience lager yeasts need more oxygen (though I’ve never seen much good data on how much). It seems logical that the same process might work fine with ales and might stress your lager yeast.
I still think the yeast will get going. Sometimes doing nothing is the right answer.
I still have to check on the wort. However, if it still doesn’t have any activity I’m going to pitch more yeast and aerate more.
I have repitched yeast into a lager before. However, the last time I did that the slurry was very thick. I don’t believe I aerated beyond pumping into the fermenters. My assumption is that the amount of cells I pitched last time was a lot higher.
Well, when I finally had a chance to check on the beer there was no krausen. Not even a hint of foam. I aerated it again and pitched one packet of W34/70 into each fermenter. Thanks to everyone for their advice!
Cheers,
Brandon
I bet it would have gotten going too, but I think under-aeration is the issue here.
Your slurry was definitely not too old (2 days after harvesting it is just fine) but in dire need of O2 which it may not have gotten enough of with your pumping method.