Stuck fermentation?

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MuddyWaters

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My second AG batch and I tried an Oatmeal Stout. OG was around 70. Real healthy looking fermentation right off the bat, but I just transferred to the secondary after a week and the SG is 28. Mashed at about 155 for an hour and batch sparged with 170 degree water. I used Wyeast Irish Ale and it has been fermenting at around 68-70. Will it hurt to pitch another batch of yeast in the secondary. I don't wan to do more harm than good. Does it sound like a stuck fermentation or just a lack of conversion? Thanks
 
It's impossible to say without seeing the recipe. That mash temp should yield a moderate amount of unfermentables. Couple that with any unfermentables that were inherent in your recipe and 1.028 might be about right.
 
155° is a bit high for the mash temp, but not out of line if you are brewing a sweet stout. I would shoot for no higher than about 153° for a sweet and 151° for a dry. You racked after only one week. I think you just racked too early. When I first started all grain several years ago, I religiously stuck to the schedule of one week in primary and two weeks in secondary. I now seldom rack out of primary in less than two weeks and sometimes leave it in there for 3 or 4 weeks and skip secondary altogether. Since letting my primaries go longer, I have gotten better attenuation and more consistent quality. Don't worry about leaving your beer in primary too long, unless you are considering letting it sit on the yeast for a couple of months. Your beer should be just fine. Just let it sit for another 3 or 4 weeks, the gravity should come down on its own. When you racked you still had plenty of yeast in suspension, but since you racked off the yeast cake early, it will just take an extra week or so for fermentation to finish out.

Just a note on fermentation, it is good to let the beer sit for another week or so after you have reached your final gravity. Even though the yeast is done producing alcohol, it is still actively metabolizing many of the fermentation by products. Many refer to this as the yeast "cleaning up after itself". If the yeast is not allowed to finish this process, you may get some "off" flavors from those by products.

Wayne
Bugeater Brewing Company
 
I've always had a high final gravity using WY 1084,but your og and sg now lead me to beleive that your ferment is done. Leaving it in secondary might get you a few points lower, but I doubt it.
 
I brewed my Oatmeal Choco Stout a week ago, congrats on yours, mine started at 1.062, plan for it to finish at about 1.016. I had the largest krausen I have everrrrrrr seen in my life. Maybe should be safe and get myself a blow off hooked up for future brews. I mashed mine at 153F. My recipe was posted here last this week.

Brewpilot
 
A high mash temperature and oatmeal would both contribute to lower attenuation & a high final gravity. What else is in the batch?
 
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