2+ Week Fermentation Time on a 2XIPA

Hey guys,
I brewed a 5.5 gal batch of Southern Tier 2XIPA Clone 15 days ago and it is still fermenting in the primary as of this morning. I used a two liter starter on a stir plate, but had to put it in the refrigerator after 12 hours or so because it was erupting like a volcano. I decanted the spent wort which had mostly cleared out and pitched all the slurry at 70 degrees or so. Fermentation did not begin for 36 hours or so, but when it did it was intense for a few days. Temperature has consistently been between 66-70 degrees. OG was 1.074 and is currently at 1.028. FG should be 1.018. Blowoff tube is still bubbling away as of this morning. I have never had a beer ferment for this long. It doesn't seem infected. Smells fine, tastes fine. Still some krasen on top.

Is this normal?

Will such a long fermentation produce off flavors/esters?

Can I help it along in anyway?

Thanks for the help.

Your recipe and mash temp would help pinpoint the problem (too much crystal, too high of a mash temp, etc). However, if it took 36hrs to take off, that is an undeniable sign of under-pitching and/or under-oxygenating. Temperatures fluctuating down also do not help. That beer should have taken off within 8-12hrs and have been done in 5-7 days, at the absolute most at 66-70F.

Suffice to say you have a problematic fermentation. You could try pitching a new starter at high krausen of alcohol tolerant yeast, but that won't help if you have a very dextrinous wort. Need more info.

Can I help it along in anyway?

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Yeast does not operate on a time clock. Each fermentation is different. Some will take off fast and finish fast. Others will just chug along for a long time.

Just sit back and let the yeast do what has been doing for thousands of years.

Do not do anything until it has had more time. You may be trying to correct a problem that you do not know exists.

g-star said:

Your recipe and mash temp would help pinpoint the problem (too much crystal, too high of a mash temp, etc).

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14#of US 2 Row Pale
2# of Marris Otter Pale
1# Crystal 20L

Mashed for 1 hour at 153F.

My first hunch is that putting your starter from room temperature to the fridge, then pitching that back into wort at 66-70 would be a pretty big shock to your yeast.

therealbenis said:

14#of US 2 Row Pale
2# of Marris Otter Pale
1# Crystal 20L

Mashed for 1 hour at 153F.

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5.8% crystal, so that's not the problem.

i agree with g-star. you under-pitched for your gravity/ & size, so you had a long lag period while the yeast tried to build up a sufficient population to deal with the job at hand. likely due to the lack of sufficient oxygen the yeast couldn't grow enough, so eventually (aka 36 hours later) the sub-par population turned its attention to munching sugars. there wasn't enough to get the job done... so here you are.

yes, that long lag period likely produced a lot of esters. the yeast were stressed

pitching a starter of alcohol-tolerant yeast at high krausen is probably your best bet. you could try rehydrating some dry yeast and pitching that, but you're at 6% alcohol already so they likely won't be very happy and might not get to work.

Update* - checked gravity again today and it is still dropping. It has dropped to 1.021 which is getting close to the target and the beer tastes pretty good already. Smells amazing. Still about 1/2" or so of krausen on top. I'm gonna let it keep going to see if it gets there. I'll let y'all know how it turns out.

great news! sounds like you won't be needing another yeast after all.

therealbenis said:

FG should be 1.018.

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be aware that 1.018 is a projected value. no two fermentations are the same since conditions are never the same. you might end a little higher, you might end a little lower. at 1.021, i'd say you're in the ballpark. this thing could end there, or might keep in chugging through.

can't wait to hear what this tastes like. i suspect that it will be a little fruitier than the original (stressed yeast).

You likely did under pitch, but it will be fine. I have had IPAs and Wheats ferment for 3+ weeks. In fact, they were some of my best brews.

Update* It has now been 17 days since brew day and this beer is still fermenting. OG has dropped to 1.014 and seems to still be going. There is still a thin layer of krausen on top. Beer tastes incredible, smells incredible. I am wondering how much further it will go. Thanks for all the help guys.

Update* Racked to secondary at 1.007.

I just did a big IIPA and it started at 1.087 and went down to 1.010. I let it go 18 days before I was satisfied it was finished out (this is with a confirmed repeat hydro reading on the last day) Big starter too.

First time experiencing a ferment that long. I was told that it would only take about 10 days to finish out. Not sure what happened.

WDT said:

I was told that it would only take about 10 days to finish out. Not sure what happened.

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there is no way of knowing how long a fermentation is going to take, because no two fermentations are the same. 10 days may be the average, but there is no guarantee that your fermentation is going to be average.