COFFEE OAT STOUT QUICK FERMENT

Ingredients
1

Hello forum, I just finished an all grain Coffee Oat Stout, 5 gallon batch and have noticed that the fermentation when I pitched the yeast, (English Ale  Yeast) had a very quick fermentation.  Now I understand that the airlock bubbles are not necessarily the tell all about what is happening in the beer but I am concerned that the fermentation process was not enough to get the gravity I need.  Is it an issue if I pitch another yeast and add it?  The grain bill is below and the yeast was pitched at a temperature of 70Deg.

10 lbs. Belgium Pale Ale
1 lb. flaked oats
3/4 lb Victory malt
1/2 lb caramel malt
1/2 lb black malt
1 lb. chocolate malt
1 lb Pale chocolate malt
Added to wort at end of boil was 28 fl ounces of kona coffee cold extract made over a steeping of 24 hours.

Mash out was 5 gallons at 168 deg. with a 60 minute sac at 154 deg. Sparged with 2 1/2 gal. at 170 deg.

Any consideration is appreciated.

Thank you

2

Have you checked the gravity on it?

3

First off, have you taken a gravity reading? there is no way to know if you have a stalled fermentation if you haven’t measured the gravity. Pitching at 70 degrees will make for a quick start and if you don’t control the temp after pitching it will only go up from there which will speed things up as well.

Take a gravity reading and see where you are at before adding any more yeast. plenty of other issues will arise from pitching and fermenting that warm though. Look for very high levels of esters (fruity flavors and aromas) and possible hot alcohol aromas and flavors (fusels) as well as possible spicey phenol levels.

on the other hand, it might be fine. let measurements and taste be your guides