Let’s assume or pretend that I don’t have a fermentation issue. Is there any reason to expect such a large difference in attenuation for the two beers below?
Beer 1:
85% pilsner
15% vienna
Mash at 152F for 60 minutes
1.053 > 1.011
W34/70 - under-pitched - 80% attenuation
Beer 2:
100% red x
mash at 152F for 60 minutes
1.051 > 1.016
W34/70 from beer 1 (calculated using mr malty) - 67.5% attenuation
if your wondering if the malt is the reason-I’d say its not likely. redx didnt cause any issues when ive used.
but as you probably suspect- yeast pitched (health, qty) and fermentation would be where I would look.
Right. I just thought it was curious that the underpitched beer would attenuate more than the beer that used 1 week old slurry. That must have nothing to do with it.
Could it have something to do with the fact that I repitched the slurry from the underpitched beer? I find it funny that I get better results from doing things incorrectly (underpitching). I guess there are a lot of other factors at play here. Maybe the wort was not oxyegenated well or something else…
right, could be any of the variables you mentioned…
Malt X has a lot less enzymes than pilsener and Vienna so the wort is more dextrinous. From what I can glean from the internet, it has barely enough enyzmes to convert so about 1/3 of that of pilsenser and Vienna.
Interesting. So maybe lack of full conversion at 152F?
I had no issue with all redx attenuating. mashed 150F and went from 1.055 to 1.010 with wlp090.
Ive made multiple 100% Red X beers and have not had this problem.
You didn’t get full conversion. Is it safe to assume you didn’t perform a iodine test?
How can you conclude that he didn’t get full conversion Why couldn’t it be something else?
Thanks all. Sounds like I either didn’t get full conversion which I had not considered or had a fermentation problem.
The sample tasted good so I am ok with it. I added 4 oz of sugar, roused the yeast, and raised the temp a bit in attempt get squeeze out a couple more points…
You can have full starch conversion, but still have a dextrinous wort. You can do a fast ferment test to determine if you have a yeast or mash issue.
I have not taken a final reading however something occurred to me…
A similar situation occurred recently when repitching K97 slurry into a brown ale. The attenuation was much lower than expected and others here suggested it is likely due depleted oxygen reserves from the dry yeast and that I did not aerate well enough. At least that is what I took from it. Is this possibly the case here? If so, it seems that my aeration method works well in direct pitching scenarios but not when repitching slurry.
Could be insufficient aeration over 2 pitches that is the problem.
There seems to be something wrong with my process (aeration) when repitching dry yeast slurry. I don’t do it very often but I seem to have more issues when I do. For me, the savings in money doesn’t appear to be worth the headache.
If you repitched a dry yeast from a previous fermentation (slurry) with poor aeration, then that could definitely be your issue. While dry yeast reportedly does not need oxygen in its initial use, subsequent generations will most definitely be oxygen deprived and in great need of proper aeration to fully attenuate your next batch of wort.
+1 to this. For the low cost of most dry ale yeast, I pretty much use a new rehydrated pack each time.
I am glad to find the cause. Until I change my aeration process, I know to just direct pitch straight from the sachets.
I kegged the beer a couple of days ago. The final reading was 1.015 so not horrible by any means. This was my 4th lager. The 3 before it went better than planned and this was my first hiccup.
You really need to be getting these lagers to 2.5p and below. 3.8p is syrup sweet.
I am good with it. Tastes fine to me.