Harvested Yeast - A Little Sluggish

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BBL_Brewer

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I harvested some pacman last night, made some starters and threw them on the stir plates. Harvested from primary at about 6 weeks. OG 1.055, FG 1.012, ~5.5% abv. It's been 19 hours and they haven't krasuened yet. There's a fair amount of condensation and the smell is starting to change a little, so I'm pretty sure it's all good, but I didn't expect them to be so sluggish. I could have harvested the yeast earlier. I knew I was going to harvest this time, but I decided to just wait longer to keg so I could pop the yeast strait into a starter.

Would it be better to harvest the yeast sooner and store in the fridge rather than let it sit at room temp for a couple more weeks under the beer? I also noticed that Mr. Malty calculates viability for the "Re-pitch from Slurry" option based on harvest date. It doesn't take into account how long the batch fermented before the yeast was harvested. What I did was tell Mr. Malty that I harvested the yeast 4 weeks ago (when my beer was two weeks in) in order to calculate my viability.
 
I often don't get much krausen when using a stirplate.

You can try the cling wrap and rubber band over the mouth of the flask test to see if it's making gas.
 
I usually get a little krausen. I don't spin super fast. My buddy has some frozen yeast on it's second step that's krausened right now, but mines not. Just thought it was odd.
 
I'd expect reduced viability at that temp for five weeks with no food. If I'm planning to harvest I usually do it at week two. If I want to keep it on the cake I transfer into secondary with half the cake. I'm careful to take a good sample of the viable yeast with beer for rinsing. Cold crash out the less flocculant and decant the beer back into the batch. I repitch the slurry for fantastic results. If I'm unsure of the viability I'll make a starter like you, assuming a conservative viability.

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Well, it looks like I may have under pitched this time. My buddy's fermentors have a nice thick krausen today. Mine have a small krausen that hasn't even covered the entire surface of the wort yet. I guess I should have either harvested earlier or made a two step starter. I would just top crop some of my buddy's yeast and toss it in my buckets, but I don't want to use that strain for this batch. I'm wondering if maybe I should hurry up and hit it with O2 again.
 
I don't think you can make a fair assessment of yeast pitch/vitality/viability based solely on the difference in krausen between to different brewers using two different yeast strains. It's like comparing salaries - you're either awesome or you suck :D

I have found better overall beer characteristics with a 15 hour lag than a 1-2 hour lag; better body, better background "beer" flavor; better yeast characteristic contributions. Also, with non "true top cropping" yeast strains I rarely will have a krausen raise higher than 3/4"; in fact, my most recent beers with a belgian strain and british strain never raised higher than about 1/3-1/2" but they have finished out nicely where I expected them to.

As to the harvesting questions: I like to harvest as soon as I can after fermentation finishes but I don't rush the stationary phase either. I like to give a minimum of 7 days in primary before doing anything and will often give a few extra days just to allow the stationary phase to really finish out. I'm typically harvesting my yeast at about 10 days but I've done 14-20 days also with good success. Your beer 5.5% is not too harsh an environment for the yeast to be sitting at for several weeks so, while you may have had a slightly higher mortality than at 2 weeks, you should still have had excellent yeast for reusing. The fact that you gave them a starter was an additional nicety I probably would have forgone if I was going from primary quickly into another batch of beer - would have just pitched a little extra slurry to make up for the few extras weeks I waited.

As I'm sure you know, your beer will likely taste fantastic and you'll be hard pressed to say that it would have been better if you had done this or that differently. And, no, don't hit it with more O2 unless you're within about 15 hours of pitching and you're fermenting a higher gravity beer.
 
In my experience I often get no visible krausen when using my stirplate. Even with the same yeast there is sometimes visible krausen and other times nothing.

Sometimes it takes a flashlight and getting really close to look for really tiny bubbles rising in the starter to know it is fermenting.

After a cold crash I look at the amount of yeast and trub on the bottom of the flask. This is just a rough sign of how much yeast had reproduced. After seeing a lot of starters I have an idea of how thick the layer should be. But then again this is after the starter has run it's course.
 
I don't think you can make a fair assessment of yeast pitch/vitality/viability based solely on the difference in krausen between to different brewers using two different yeast strains. It's like comparing salaries - you're either awesome or you suck :D

Well, in this case I think I can. It's the same beer, same mash (we mashed our grains together), same gravity just two different boils with different hops and different yeast. Pitched within two hours of each other. Same pitching temps. Plus, it's not so much the fact that his has more krausen as it is the fact that mine should have more at this point. I've used this yeast a few times now I know how it usually acts. It's not performing as it usually does. But, this is also the first time I've harvested this yeast instead of starting from a frozen culture.

Your beer 5.5% is not too harsh an environment for the yeast to be sitting at for several weeks so, while you may have had a slightly higher mortality than at 2 weeks, you should still have had excellent yeast for reusing.

That's what I thought. But now I'm not convinced, which is why I posted to get some other brewers insight on harvesting late.

As I'm sure you know, your beer will likely taste fantastic and you'll be hard pressed to say that it would have been better if you had done this or that differently. And, no, don't hit it with more O2 unless you're within about 15 hours of pitching and you're fermenting a higher gravity beer.

Yeah, I'm sure it will ferment, but I don't want it drastically underpitched either. OG is 1.065. Pitched at 10 pm last night, temp is at 64F. I'm still considering more O2. Especially since I've heard of brewers adding more O2 up to 24 hours later for very high gravity beers. My gravity isn't that high, but I'm thinking at this stage in the game, a little more O2 won't hurt. Could be wrong though. I might just let it be.
 
Well I spoke too soon. I guess that two hour lag between pitching to his batch and mine made all the difference. I just went down to check on things to see if I wanted to add more O2 or not and my krausen is almost up to the top of the buckets now. I guess I should have just RDWAHAHB. It's a lovely stout recipe and I'm really looking forward to it. I guess I was just a little paranoid this time. Thanks for the feedback guys. If I harvest this late again though, I think I will make a two step starter just so I don't have to worry.
 
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