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Just curious about experiences other folks might have had with Wyeast 2105 PC Rocky Mountain Lager yeast. I've brewed twice with it before in the past year (Coors Light and Coors Banquet clones) with very good results. I'm on a 3rd generation pitch starter right now in a Pre-Prohibition lager that I usually ferment with WLP-830. I'm 5 days into fermenting at 50F, and the activity is slow in the blow-off line. Very slow.
The base yeast for the starter was harvested from a previous batch last April and took off quite well into a quart of prepared 1.040 wort and reached active krausen within 24-36 hours. I only propagated 1 quart since this was the last jar of my homemade starter wort. I crashed, decanted, then pitched ~800 ml of thick, viscous slurry into the fermenter. The wort and yeast were both at or near 50F. I oxygenated for 60 seconds after pitching and capping the fermenter.
After nearly 50 hours there was no visable activity in the blow-off. I was getting ready to give the yeast a burst of CO2 to kick start the process when I noticed a lone bubble.
"IT'S ALIVE!!!"
I raised the temperature to 53F, and after 4-6 hours there was a slow but steady parade of bubbles in the blow-off, however the rate hasn't increased past this stage of 8-10 bubbles per minute, and it's 5 days into fermenting. Gravity has dropped about 12 points, down from OG 1.045, so I know it's fermenting. My predicted FG was 1.009, but the FFT measured out at 1.004 after two days on a stir plate at room temperature. The FFT sample was done in the same Erlenmeyer flask as the pitched yeast, and the sample was drawn from the fermenter immediately after the pitch. Even though it's often the case that an FFT will finish 1~2 points lower than an actual fermenter wort, I have a hard time believing that it would be 5 points lower than my calculated estimate. 2105-PC only has an estimated attenuation of 70-74%.
So, the FFT took off like a rocket and finished way low, but the fermenting wort took forever to start and developed only a slow, weak stream of activity. This is not the way I remembered this yeast acting on the two previous times I used it. The malts bill is very similar to what I used before with 2105 yeast. The previous harvests of the yeast were clean and properly stored, and not more than 6 months old. There weren't any exotic adjuncts or chemicals used in the process. My notes from the previous brew sessions don't indicate anything unusual or out of the ordinary for a basically simple lager.
There shouldn't be much genetic shift in the yeast after just two generations (actually, only one generation since the 'first' was simply an over-built starter). Just curious if anyone else has had similar experiences with this yeast. My usual go to lager yeasts are WLP-830, 838 and 840.
Comments and suggestions appreciated.
Brooo Brother
The base yeast for the starter was harvested from a previous batch last April and took off quite well into a quart of prepared 1.040 wort and reached active krausen within 24-36 hours. I only propagated 1 quart since this was the last jar of my homemade starter wort. I crashed, decanted, then pitched ~800 ml of thick, viscous slurry into the fermenter. The wort and yeast were both at or near 50F. I oxygenated for 60 seconds after pitching and capping the fermenter.
After nearly 50 hours there was no visable activity in the blow-off. I was getting ready to give the yeast a burst of CO2 to kick start the process when I noticed a lone bubble.
"IT'S ALIVE!!!"
I raised the temperature to 53F, and after 4-6 hours there was a slow but steady parade of bubbles in the blow-off, however the rate hasn't increased past this stage of 8-10 bubbles per minute, and it's 5 days into fermenting. Gravity has dropped about 12 points, down from OG 1.045, so I know it's fermenting. My predicted FG was 1.009, but the FFT measured out at 1.004 after two days on a stir plate at room temperature. The FFT sample was done in the same Erlenmeyer flask as the pitched yeast, and the sample was drawn from the fermenter immediately after the pitch. Even though it's often the case that an FFT will finish 1~2 points lower than an actual fermenter wort, I have a hard time believing that it would be 5 points lower than my calculated estimate. 2105-PC only has an estimated attenuation of 70-74%.
So, the FFT took off like a rocket and finished way low, but the fermenting wort took forever to start and developed only a slow, weak stream of activity. This is not the way I remembered this yeast acting on the two previous times I used it. The malts bill is very similar to what I used before with 2105 yeast. The previous harvests of the yeast were clean and properly stored, and not more than 6 months old. There weren't any exotic adjuncts or chemicals used in the process. My notes from the previous brew sessions don't indicate anything unusual or out of the ordinary for a basically simple lager.
There shouldn't be much genetic shift in the yeast after just two generations (actually, only one generation since the 'first' was simply an over-built starter). Just curious if anyone else has had similar experiences with this yeast. My usual go to lager yeasts are WLP-830, 838 and 840.
Comments and suggestions appreciated.
Brooo Brother
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