Learned a valuable lesson. I recently made an Irish Red. Used the same recipe as I did back in January. It was good but a bit fruity. This was rather puzzling until I just tapped a Belgian Tripel I brewed in August. It’s OK but it’s fruity! I went back and looked at both recipes and they had a common denominator… I used some washed yeast. I brewed the Red in August and used some fresh yeast and some washed yeast from earlier in the year. I brewed the Tripel in August and used some fresh yeast and some washed yeast from last year. In June, I removed the washed Irish yeast, decanted and ranched up again. I did the same to the Tripel yeast in March and June. I do not recall if I added water after ranching back up. Don’t know if it makes a difference or not. Anyway, If I reuse a yeast cake again it will be no older than 1 month!!!
I just started washing and reusing yeast. I recently brewed a Hefeweizen with yeast that I had in the fridge for about 3 months. I took one mason jar and made a starter. It came out great and I couldn’t tell a difference between the first batch w/ WY3068 and the second one with the washed 3068. Same results with an Amber I did earlier in the year when I used washed WY1056 that was about 3 months old. Again, I made a starter with that batch. I’ve read posts on here and other places where brewers have had success with much older washed yeast product.
I made yeast starters for the washed and fresh yeast. Didn’t combine until I knew that both had taken off. I’m sure cell count was not the issue.
interesting observation. Since you mixed yeasts its difficult to tell if the increased esters came from the fresh or old yeast.
I don’t think old yeast slurries perform well and in your case, where a new and pure culture is available, I suggest propagating a full pitch from that. Even with old slurries I suggest propagating from a small sample if the purity of the yeast can be trusted.
There are lots of contradicting statements regarding ester creation by yeast. One thing that is common to all is that acetyl CoA, an intermediary compound that the yeast produces when it metabolizes sugar, becomes available for ester production. That can happen when the yest produces more than it can use for its growth. An “overflow” of this compound into ester production can be caused by many factors including yeast health, I think.
Kai
I gotta think the esters came from the washed (old) yeast. I’ve used these yeasts before in the same beers, pitched at the same rate and fermented at the same temps. My guess the old yeast was just a bit tired. I wonder if keeping them at fridge temps for so long makes the viable ones throw off these fruity esters? It is possible after I woke them up in the summer that I did not add water for storage. I just don’t recall.
BTW I used WY1338 for the Irish and WY1214 for the Tripel…
It could just be your yeast choices, too. I found 1338 a bit fruity before I stopped using it. 1214 is VERY fruity, especially if fermented above about 62F.
That was my first thought too. At any rate, I wouldn’t pitch a 2-3 month old slurry without harvesting and building it back up. Especially not if there’s fresh yeast available to work with.
As Kai pointed out, an increase in esters could also possibly come from pitching more yeast than usual.
I have a hard time with this yeast at temps that low.
And I can’t stand it at higher temps, so I avoid it! 
Good deal. More for me!
Really, I’m on week 3 trying to get a batch to finish. I pitched at 60, warmed it up to mid 60s after two days and it’s stalled at 1.050 from 1.088. I had to swirl it and raise the temp to about 68 and it seems like it’s going again. Reminds me of my experiences with Belgian saison yeast.
I’ve been having the same problem recently.
http://www.homebrewersassociation.org/forum/index.php?topic=13773.0
Yes. I saw that post and almost posted there as well. Mine was a repitch also. I think 3rd gen, but I don’t recall for certain.
Never had the Chimay stall on me. Do you guys oxygenate and use nutrients? The 1338 was REALLY slow back in January. A lot quicker in August. More info:
Irish Batch1: start 1.062, finish 1.013 (start at 62°F. Raised 2°F every 4 days until 68°F)
Irish Batch2: start 1.052, finish 1.013 (start at 64°F and ramped to 70°F over the next 3-4 days)
Chimay1: start 1.093, finish 1.007 (started at 64°F for 3 days then let it rise to 70°F for the duration)
Chimay2: start 1.076, finish 1.012 (started at 64°F for 3 days then let it rise to 70°F for the duration)
I oxygenate. I do not use nutrients. I am pitching a healthy starter or using recently harvested slurry.
I’ve never had it stall before, but I have had some serious issues with flocculation to the point where I had to use gelatin to clear the beer and even then if you moved the keg at all you would get some major yeast.
I attribute the recent stall to pitching it at 60 and putting the fermenter in a cold room set at 60 degrees. I know Denny says he likes it at lower temps, but this is the only thing I did differently this time. I also put an English ale in the cold room at the same time (London ESB yeast) and that fermented out no problems, though starting at a much lower OG.
I seem to have the Chimay yeast working again, but I won’t know for sure until the weekend when I can pull a sample.