Ask Mr. Wizard

Finishing A Fermentation Strong

TroubleShooting

Roberto Caballero — Lima, Perú asks,
Q

I have a fermentation issue with a New England IPA I just brewed. It’s been in the fermenter at ~65 °F (18 °C) for 22 days and it is taking longer to finish fermenting than usual. By now it should have been finishing fermentation below 1.020, but I have two fermenters over 1.020 (1.022 and 1.024); the other one is 1.018 (I brew 50-L/13 gal. batches and split them into (3) 5-gallon (19-L) fermenters). This time I made a 3-L (3-qt.) starter with one vial of White Labs WLP008 (East Coast Ale). Two days ago, I used another WLP008 vial and added a third of the vial in each fermenter. I see activity from the airlock but it is taking a lot of time. My inquiry here is what I should do next? Should I add another WLP008 vial? The final gravity should be around 1.012–1.015. I have two different hydrometers, so I trust the measurements. I mashed a blend of pale malt, malted oats, white wheat malt, and Vienna malt at 151 °F (66 °C) for an hour. the starting gravity was 1.061.

A
Whenever there seems to be an attenuation problem with a batch, I think it always helps to go through a mental check list of the basics. This checklist of mine includes the
Response by Ashton Lewis.