Stalled fermentation

A buddy made a Rye IPA the other day.

Making 15gal

We kept 10, another guy took 5.

I don't know the full grain bill or temps so on but here is the little I know


10lb rye
30lb 2row
3lb caramel malt
And a few other specialty grains

Mashed at 157

Used some kind of Scottish ale yeast they harvested from a brew that just finished.

OG 1.064

So about 14 hours after pitch, there was MAJOR activity. Honestly the most violent fermentation I've ever seen. It stopped within 3 days so I figured it was already finishing up seeing as the blowoff hose sounded like a machine gun for 2 days straight.

We let it sit for a few more days and decided to check our OG. Both of our 5 gal fermenters are stalled at 1.04...

Because it was both of them, I ruled out sanitization issues for the most part. I just don't get why it was fermenting like madness and WAY overusing the blowoff, and then just stops?

Never used rye before, so maybe it has something to do with that?

Need advice and an explanation please!

Bhunter87 said:

A buddy made a Rye IPA the other day.

Making 15gal

We kept 10, another guy took 5.

I don't know the full grain bill or temps so on but here is the little I know


10lb rye
30lb 2row
3lb caramel malt
And a few other specialty grains

Mashed at 157

Used some kind of Scottish ale yeast they harvested from a brew that just finished.

OG 1.064

So about 14 hours after pitch, there was MAJOR activity. Honestly the most violent fermentation I've ever seen. It stopped within 3 days so I figured it was already finishing up seeing as the blowoff hose sounded like a machine gun for 2 days straight.

We let it sit for a few more days and decided to check our OG. Both of our 5 gal fermenters are stalled at 1.04...

Because it was both of them, I ruled out sanitization issues for the most part. I just don't get why it was fermenting like madness and WAY overusing the blowoff, and then just stops?

Never used rye before, so maybe it has something to do with that?

Need advice and an explanation please!

Click to expand...

Hmm....what are you using to check the SG, a hydrometer or refractometer?

Hydrometer.

Refract gets messed up by alcohol content

It also has a kind of soapy yeasty smell

Bhunter87 said:

Hydrometer.

Refract gets messed up by alcohol content

It also has a kind of soapy yeasty smell

Click to expand...

Ok I was just making sure....many people don't know that you have to adjust for alcohol when using the refracometer.


As for the smell, I wouldn't be too concerned about infection or anything like that. Most likely just the "lovely aroma" of fermenting wort.

You have verified your hydrometer is calibrated correctly? Seems odd that you had such an active fermentation for such a high reading.

You said it was harvested yeast....any idea what kind? Or the health/pitching rate? Was it washed or did you just pitch the slurry? Also what temps are you fermenting at?

What day are you on? Have you taken an SG reading a few days apart to see if it's stable? It sounds like its just not done yet.

I had the same thing just happen with some yeast harvested from Ommegang Hennepin. I was advised to use 3711 (obviously wouldn't work with this style) but perhaps there is a super yeast you could throw on top of that. Bell's and 1056 attenuate pretty well?

A mash temp of 157, combined with a Scottish ale yeast (which tends to be lower attenuating) can give you a high FG- but 1.040 seems really high (36% attenuation- far less than you should have got).

My guess is that the mash temp crept above 157, and that the Scottish ale yeast may have been underpitched or a combination of the two. A mash temp of 157 is really hard to manage, because if your thermometer is off by even two degrees and you miss your mash temp by one or two degrees, you could be mashing at 161! Are you certain your thermometer is correct?

I wouldn't ever mash an IPA above 153, especially one with crystal malt in it and would probably lean more towards 151. And using Scottish yeast would definitely lean towards "sweet". The thing is, Scottish yeast (at least the Wyeast version) does have a very high alcohol tolerance so if there are fermentables in there, it should find it.

I'd dry to rouse the yeast by swirling the fermenters (Scottish ale yeast is highly flocculant) and bring the temp to around 70 degrees. If that doesn't work, I'd repitch a starter of Wyeast 1056.

The other thing that comes to mind is that with 43 pounds of fermentables, I'd expect a far higher OG. So either the efficiency was terribly low, or they didn't get much conversion, or both. Not getting much conversion could definitely be a cause of the now high FG.

Yeah I had no part in this brew process so I can't give much info more than what I remember him saying a week ago. They brewed last Sunday.

I also assumed that the OG would be much higher but didn't really argue with the guy who looked at their hydrometer.

Regardless, I also gave him the advice to swirl and check it again in 3 days, and if nothing
Has moved, repitch. Any reason why the wyeast strain you recommended would be best yoop?

Also thanks for the info. I've only done 2 ag batches so I'm not too educated on all of this

Bhunter87 said:

Yeah I had no part in this brew process so I can't give much info more than what I remember him saying a week ago. They brewed last Sunday.

I also assumed that the OG would be much higher but didn't really argue with the guy who looked at their hydrometer.

Regardless, I also gave him the advice to swirl and check it again in 3 days, and if nothing
Has moved, repitch. Any reason why the wyeast strain you recommended would be best yoop?

Also thanks for the info. I've only done 2 ag batches so I'm not too educated on all of this

Click to expand...

It's clean and attenuates well.