High gravity beer fermentation times

[austinb]

Hi, I usually brew lower gravity brews around 1.050-1.060 which usually take about a week to fully ferment before I transfer to a secondary. I recently brewed an imperial porter with a gravity of 1.078, it seemed to be finishing up after about a week due to the bubble frequency in the air lock so I transferred it to the secondary however it tasted a bit sweet still and since transferring it picked back up and has stayed steady at about 8 seconds per bubble and is still at that rate now 2 weeks after brewing it. I don't remember it taking this long for the couple other high gravity brews I've done in the past. Its only 5 gallons so I don't want to take another gravity reading until it seems to slow down a bit more. I expected it to take a little longer but not this long, is it normal for it to take over 2 weeks? Should I add a yeast which can withstand higher alcohol content such as a champagne yeast to finish it out or should I avoid that because it would make my porter too dry?

PS. I just tried another sample and its still somewhat sweet.

 

[avidhomebrewer]

All depends upon how viable the yeast is, how big of a starter you made, the temp you are fermenting at, the grain bill, etc. For all my beers, regardless of strength, I keep in primary for about a month, then rack if needed. So yes, I think 2 weeks isn't long enough in the carboy. Rouse the yeast and move to a warmer area if necessary. Also, don't go on how many bubbles/time frame; rely on your hydrometer to tell you when it is done.

 

[naterzr2]

+1 avidhomebrewer!

Airlock activity means squat when it comes to when to transfer. It's all about the gravity readings. I personally leave all beers in the primary for a minimum of 3 weeks. Plus, the yeast "clean" up flavors produced during fermentation and produce little to no gases for airlock activity.

As for your question, before you dump any more yeast in there, get a gravity reading. If it's still higher than you'd like, pitch some dry yeast like Safale05. I read somewhere on here that the yeast flavors are produced early, so repitching wouldn't affect flavor too much.

Hope this helps.

 

[BendBrewer541]

I've noticed that my last 2 higher gravit beers did take longer than I was used to. I would just be patient and leave it alone for a while until it looks like it's done, then take a reading. Like avidhomebrewer said, there are multiple factors that can affect your situation.