High Final Gravity: Oatmeal Stout PM

I recently brewed a batch of Northern Brewers Partial Mash Oatmeal Stout and I seemed to have a very high final gravity read of 1.020 with a original gravity of 1.049. I used the Wyeast London Ale III strain and made a 1L starter with it. The Wyeast smack pack did arrive a bit inflated however but I created the starter shortly after the yeast arrived. I also aerated the wort pretty vigorously for about 2 minutes. Anybody have an idea of what could have caused this high final gravity? My krausen seemed a bit thin compared to other batches. I’m wondering if the ambient heat during the shipment of the yeast had an effect? Anything I can do to lower it down?



13C. Oatmeal Stout

Vital Statistics: OG: 1.048 – 1.065
IBUs: 25 – 40 FG: 1.010 – 1.018
SRM: 22 – 40 ABV: 4.2 – 5.9%

you really aren’t that high out of style guidelines on final gravity. And with the use of dark malt syrup, dark dry extract, 1/2lb of medium crystal, and the black malt, it is not that shocking that it ended high.

+1 to this ^^^. Lots of unfermentables and not a high attenuating yeast. This is the main reason I moved to partial mash and then all grain rather quickly. I got tired of extract kits finishing with a high FG. Not to say an Oatmeal Stout should finish dry, because it shouldn’t, but overall extracts finish much higher than I like. And it’s damn near impossible to get a dry finished beer while using all extract.

Thanks guys. Thats what I was thinking due to the dark extracts. I’ll be moving over to all-grain later this month so hopefully I’ll be able to get some consistency with my FG’s when brewing these darker beers.