Hey guys. I recently brewed a kolsch and since it's been a few months since I last brewed some things slipped my mind (like my yeast). I pitched a pack of k-97 that's been sitting in a container in my garage for about 10 months (oops, thought i put that in the fridge). It was part of a NB monthly subscription; tossed the package so I can't tell you what the exp date was.. anyways, it's been 56 hours and I've only dropped 20 points at 67° (47% attenuation). Gravity hasn't moved in 16 hours. My LHBS doesn't open until Wednesday. Am I worrying too much or did I just waste a batch? Is waiting 96 hours too late to pitch another pack?
Wait or worry?
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Alan Reginato
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Yes, let it be. If the airlock still bubbling I not even do readings anymore. I wait until fermentation slow down. So, probably it's fine.
Yeah i would also give it some more time, since it dropped 20 points already it seems the yeast is still ok., you are probably just in the yeast its lag phase now, when it changes itself to eat the more complex sugars.
At what temperature are you fermenting?
Is that a stable temp, not fluctuating or dropping during the night? Keeping fermentation temperatures steady is most important.
BTW, although keeping dry yeast refrigerated is best, in her original, unopened pouch she's quite hardly. As long as the little yeast pellets were dry and not clumped or paste-like, she should be OK.
Is that a stable temp, not fluctuating or dropping during the night? Keeping fermentation temperatures steady is most important.
BTW, although keeping dry yeast refrigerated is best, in her original, unopened pouch she's quite hardly. As long as the little yeast pellets were dry and not clumped or paste-like, she should be OK.
Stikius
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Agree with all of the above. In theory it should only require one live yeast cell to be able to reproduce and ferment out the batch. It will take "some time" for it to reach big enough population to see any activity though. In practice however, I wouldn't settle with pitching one yeast cell only 
But a 10 month old dry yeast should be healthy enough to use, assuming other conditions (as mentioned above) are favorable.
But a 10 month old dry yeast should be healthy enough to use, assuming other conditions (as mentioned above) are favorable.My Temps swing between 67 and 68. Still no movement this morning but I'll wait. If by tomorrow it hasn't began dropping again I'll pitch another pack.
I'm also going off a tilt and not pulling samples as I care less about exact gravity atm vs changes but maybe something happened to the tilt? This stall coincides with me changing my blowoff tube to an airlock. Could that have changed something?
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Your tilt may have some accumulated krausen that is making it float a little higher so it reports a high final gravity. it is time to pull a sample for the hydrometer.
What kind of fermenter do you have? Can you see inside it without opening lids and such? If so, do you see foam layer on top of the beer?
An airlock not bubbling doesn't mean the beer is not fermenting; fermenters can have leaks for gas to escape.
Since you had about 50% attenuation, there's no reason the yeast would just stop there, she's also not going to grow much anymore while in fermentation mode, and an extra pitch at this point isn't going to add many more cells.
Just did. Reads the same as the tilt.
Just a bucket got some foam. I've never had this happen before. Now I'm worried that since I switched my blowoff to the airlock and it hasn't changed that the O2 i let in isn't getting purged.
Do I try to agitate it? Maybe I didn't oxygenate the wort enough...
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VikeMan
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I'd say you may be worrying too much. I'd advise patience.
I agree with "give it some more time," but with a 20 point drop, the yeast has definitely moved past the lag phase.
Starting with one cell, you'd never reach the call mass that you would in a normal fermentation, because the resources just aren't there for that many cell divisions (budding). But I agree with the main point I think you were making, which is that his yeast pitch was probably good enough, given the progress so far.
I can't think of any reason it would.
Some amount of whatever O2 may have got in may reach the beer, depending on how strong the outgoing stream of CO2 is(n't). It may not be ideal, but people have been doing worse things (from an O2 perspective) than switching airlocks without necessarily ruining their beers.
redrocker652002
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In looking at your photo, I say let it go. When the yeast is done, it settles into a nice flat cake at the bottom. Yours has jagged edges to it. Mine does that while it is still fermenting. Once done, it should settle into a nice smooth cake. Just my two cents worth, and I am no pro, so take it for what it is worth.
No, no need to agitate at this point. The yeast, actively fermenting, agitates the beer plentifully.
The foam (krausen) is testimony to the beer fermenting, and quite actively.
That thick foam may also be lodging your Tilt nicely, that's why her report is flat-lined.
Dry yeast doesn't need oxygen per se, she has her sterol reserves built up already at packaging time.
Liquid (wet) yeast, however, does need a good dose of oxygen when pitching.
Thanks everyone. I'll wait it out and see what happens.. worst thing is I have a 2.5% kolsch lol. My impatience is very much attached to just building a keezer and I want to try it out. I'll post back the final results.
FloppyKnockers
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So as of now it's only been 42 hours since pitch? Yeah, I'd recommend you wait least till day 4 before really wondering why the SG isn't going lower.
20 points and 47% attenuation. So I'm guessing your OG was about 1.42 and you now are sitting at 1.022. That's not bad for just the short amount of time so far.
You seem to have a good krausen going in the FV. Pulling the lid to pitch more is just inviting more disaster if there isn't enough sugars left for any yeast to use up the O2 you let in. Or possibly I'm wrong and yeast aren't consuming the sugars when they use the O2. I'll have to go read up on that.
20 points and 47% attenuation. So I'm guessing your OG was about 1.42 and you now are sitting at 1.022. That's not bad for just the short amount of time so far.
You seem to have a good krausen going in the FV. Pulling the lid to pitch more is just inviting more disaster if there isn't enough sugars left for any yeast to use up the O2 you let in. Or possibly I'm wrong and yeast aren't consuming the sugars when they use the O2. I'll have to go read up on that.
Update: after doing some reading and reflection on the brew day process, I may have found the issue if the gravity doesn't end up moving. This is only my 2nd BIAB attempt and so I'm still learning a lot. I was supposed to mash at 152° for 60 minutes. If my memory serves correctly, my strike water was at 175° (mind you I was distracted with kids and pets) when I began to mash. I think I sat around 170° for a while and it slowly dropped to after 60 minutes my thermometer read 155°.
Maybe I killed my conversion and the reason I'm stalling is there's nothing left lol.
Lessons to be learned for sure.
My OG was 6 points lower than my anticipated. I did need to add about 3/4 gallon for top-up as well.
Maybe I killed my conversion and the reason I'm stalling is there's nothing left lol.
Lessons to be learned for sure.
My OG was 6 points lower than my anticipated. I did need to add about 3/4 gallon for top-up as well.
Give it another day, take a hydrometer reading. If it's still stuck, you could pitch another pack of yeast. It wouldn't matter so much which strain. Any fairly neutral dry ale yeast should do--US-05, Nottingham, etc. Sprinkle it in dry and give it some more time.
You'll get some O2 ingress repitching, but you are salvaging the beer at this point. It just might turn out OK. Don't give up on it until you are sure it is bad.
You'll get some O2 ingress repitching, but you are salvaging the beer at this point. It just might turn out OK. Don't give up on it until you are sure it is bad.
You could try using amylase enzyme. I've never used it myself, but I would give it a shot if I mashed too hot.
Alpha. Not gluco. Unless you want a FG < 1.
Your mash temp surely plays an important role in fermentability, sure!
But only a 5 degree drop? I would have expected it to have dropped quite a bit more, though:
Your bag with milled grain is cold, 60-70°F perhaps, so the temp would drop it quickly from 175° to some intermediate value as you stir the grist.
After a few minutes stirring, I reckon it should have settled somewhere in the 155-160F region, which would indeed be a bit high.
Now if you do a full volume BIAB mash (no water left behind for sparging) it may have indeed ended up in the low 160s! Ouch!
Did you take a temp reading after stirring, before the mash rest? I always do, and recommend you do too. That's when and where you can still make a temp correction.
For example, I underlet my mash (dry grist mix in a dry, preheated tun). The strike water (~174F) streams in through the (bottom) valve while I stir the mash until it's all well hydrated. That takes about 5 minutes. The final temp of the mash is usually pretty close to the intended sacch rest temp.
I take temp readings while stirring, and when it's a few degrees higher than intended I correct that by adding some cold water while stirring more. That gets it to the intended rest temp quickly.
Yeah I'm not sparging and I'm doing BIAB in a keggle. I use the thermometer installed on the keggle which I checked last brew and it was reading correctly.
My grain bill was 10 lbs of grain, 8 oz rice hulls in 7 gallons of mash water. Grain temp was about 68°. I thought it was weird as well that the temp didn't drop that much after stirring everything together and ensuring no balls.
There are mash temp calculators around for quick mash temp predictions.
It's always easier to drop the temps by adding cold or ice water, than it is heating up by adding boiling water. So it's not bad to start a tad higher and adjust it downward. You get a good feel for how much is needed.
Insulating the (mash) kettle guards against temp loss during the hour-long mash. Especially outdoors in cold or breezy weather. Don't forget to insulate the lid too.
Many of those sidewall mounted temp gauges are slow to respond. After many years of futzing with various thermometers I finally bought a Thermapen, in one of their "open box" sales with a nice discount. I always wish I had done that 10 years earlier!
48 hours since the last update. Talked to my LHBS and the head brewer suggested to pitch energizer, a new pack of yeast, stir, and bump the temp up 2 degrees. I did that yesterday and dropped 2 points.. been stuck at 1.020 for 34 hours. Now I'm almost positive that since I stirred and pitched I most definitely have oxidation 
. If by tomorrow afternoon things don't change I'll treat the bump of temp as a diacetyl rest and proceed to cold crash. Maybe I'll enjoy a 2.8% kolsch..
. If by tomorrow afternoon things don't change I'll treat the bump of temp as a diacetyl rest and proceed to cold crash. Maybe I'll enjoy a 2.8% kolsch..
Is there still a layer of foam on top?
Nah, when I pulled the kid open to pitch new yeast it was all fallen back down.
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As long as it's been most all of your fermentation is over. You might get a few more points, but I wouldn't have pitched the nutrients this late in the game. It might still be good enough beer at 1.020 or the few points under.
Might need to look at your mash temps and water. If you are only taking the mash temp in one place then temps in other parts might be way over temp and you just made a lot of unfermentable sugars. Also water chemistry might be giving you grief, but for pale ales, IPA's and such that's not been a big deal for me. It does seem to be a deal for the dark stouts I failed miserably at.
Might need to look at your mash temps and water. If you are only taking the mash temp in one place then temps in other parts might be way over temp and you just made a lot of unfermentable sugars. Also water chemistry might be giving you grief, but for pale ales, IPA's and such that's not been a big deal for me. It does seem to be a deal for the dark stouts I failed miserably at.
Yeah, mash Temps is what I'm contributing this failure to. I need to get this beer out of the chamber so I can put another one in.
Only the bump in temperature is useful, neither of the other two suggestions.
The high mash temps are pointing that way, making the wort much less fermentable, especially for a Kölsch yeast.
Yeah, good learning opportunity for me. I figured it can't hurt to try. Worse thing I do is dump a semi old kit from NB.
