I recently brewed a 1064 extract ipa that used wyeast 1056. When it arrived in the mail i noticed the yeast pack was more swollen than normal. The pillow inside was still intact, so I went ahead and made a starter using the mr malty calculator. The starter seemed to work right, but now my ipa has stopped at around 10185, and the recipe called for a fg of 1014. I bumped up the temp from 65* to 70*, stirred the yeast up a bit, and added some fresh nutrient, with no more activity. My question, might my higher than expected fg be caused by a possibly compromised yeast pack, or is it more likely some other reason? I have had many of my ales finish higher than expected in the past, but not 4 points higher. Another question would be what are the most common reasons for extract ales finishing higher than expected?
If it was my beer, I would not worry about the difference between 1.014 and 1.018. If you are the options I see are, wait longer, raise the temp more, stir more, add more yeast or a combination of those ideas. First would be wait a few days and take another reading.
My guess is that it will be fine.
Master brewer, I will have to wait and might also try another re-start. One reason I want to drive it down more is that I bottle my beer, and have had over carbonated bottles before which I assumed was excess sugar from under attenuated beer. Do you suggest going higher than the 70* I am at now? Wouldn’t I risk fusal or ester off flavors if I go much higher?
Fusels and esters come from the beginning of fermentation so you can be safe going higher than 70. I think you’re probably done, though, given that this an extract recipe.
I have read that extracts will often stop at about 1.020 and everything is still OK. The difference between 1.014 and 1.018 is minimal.
If your bottles were over carbonated it was probably not due to under attenuation, unless the fermentation stalled much higher. I would suspect too much priming sugar or an uneven mix.
After the initial period of fermentation has passed and you are close to final gravity it does not hurt to let the beer warm to room temperature. (unless you are are in the tropics)
The swollen smack pack is also of no concern unless it got hot enough to kill the yeast. Since your beer has fermented it is evident that was not the case in this situation. I read an article by Wyeast that sometimes the packs will swell and it is not a problem. I had one that was almost totally inflated, so much so that I could not break the nutrient pack. I made a starter and cut open the pack and dumped it in. The starter progressed normally and the beer was perfect.