Nottingham underattenuation issues

[lautzki]

Have you guys experienced underattenuation problems with Lallemand Nottingham? My dry Irish stout has been fermenting for almost a week now and has been sitting at a stable 1.016 FG for 4 days. The yeast has completely crapped itself out and flocced in a tight cake at the bottom of my FermZilla. This is particularly odd, because I thought my grist would translate into a fairly highly fermentable wort, and I've also heard that Nottingham is a crazy attenuator:

70% MO
20% Chit Flaked Barley
10% Roasted Barley

Mash temp: 65c

Expected OG: 1.041
Expected FG: 1.010
Actual OG: 1.042
Actual FG: 1.016

I chilled the wort down to 18c, transferred the wort by draining it from the kettle to my primary from a quite tall height to get some aeration going in (so heavy splashing and foaming happening), aerated by giving it a few good splashes, and pitched non-rehydrated Nottingham. I then set the fermentation chamber to 15c.

I actually experienced the same underattenuation with my pressure-fermented pilsner (W3470) even though I pitched two packs into fairly low OG wort. It makes me think I either have oxygenation/nutrient issues or my LHBS is supplying old yeast.

Is there anything I can do to get it to finish drier? I know there will be answers stating "a week is too little", but remember that we are dealing with Nottingham here.

 

[JoeSpartaNJ]

I think you fermented this a bit on the cooler side.

Maybe raise the temp to 20c (68f)? This might help you gain a few points

 

[Miraculix]

I'd say that you have probably an issue with your mash thermometer.

 

[lautzki]

I think you fermented this a bit on the cooler side.

Maybe raise the temp to 20c (68f)? This might help you gain a few points

Thanks, I'll give it a try.

 

[lautzki]

I'd say that you have probably an issue with your mash thermometer.

I'm using a newly purchased KegLand instant read thermometer with a temperature error of +-1c. I have checked this against my other thermometers as well.

 

[Miraculix]

I'm using a newly purchased KegLand instant read thermometer with a temperature error of +-1c. I have checked this against my other thermometers as well.

Ok, that's good then it's something else. Nottingham isn't that high in attenuation. I get something between 70 and 75 on a regular basis. How do you measure your gravities?

 

[lautzki]

Ok, that's good then it's something else. Nottingham isn't that high in attenuation. I get something between 70 and 75 on a regular basis. How do you measure your gravities?

That's still way off from the 60% attenuation I'm getting.

I measure my pre-boil and original gravity using a traditional hydrometer suspended in 20c wort. I monitor the FG using an iSpindel.

 

[Miraculix]

That's still way off from the 60% attenuation I'm getting.

I measure my pre-boil and original gravity using a traditional hydrometer suspended in 20c wort. I monitor the FG using an iSpindel.

OK there's the problem. The ispindel is good in telling you when fermentation has finished but not in telling you at which specific final gravity.

If you use your normal hydrometer you will very likely get a different result within the normal range of attenuation.

 

[lautzki]

OK there's the problem. The ispindel is good in telling you when fermentation has finished but not in telling you at which specific final gravity.

If you use your normal hydrometer you will very likely get a different result within the normal range of attenuation.

Oh sorry, I think forgot to mention that I did measure the FG with my actual hydrometer. Even though the iSpindel values are offset to match my hydrometer readings, I never trust it for actual gravity values - I rather use it to monitor the trend.

I just took a sample and it reads the same value: 1.016.

 

[Miraculix]

Oh sorry, I think forgot to mention that I did measure the FG with my actual hydrometer. Even though the iSpindel values are offset to match my hydrometer readings, I never trust it for actual gravity values - I rather use it to monitor the trend.

I just took a sample and it reads the same value: 1.016.

Ok, then I have no idea what's going on. I've had high protein malts cause higher gravity, maybe that's the case with the flaked barley as well?

 

[lautzki]

Ok, then I have no idea what's going on. I've had high protein malts cause higher gravity, maybe that's the case with the flaked barley as well?

Hmm, good point. I'll look into some specifications about the particular flaked barley I used. FWIW, I used Castle Malting's Chateau Chit Flaked Barley.

 

[hotbeer]

When you check your mash temps are you checking in many places or just a few. Since you said that you had trouble with another brew and different yeast then I'd think something other is up than just a yeast issue.

And perhaps if you are having to apply heat to your mash, you might be letting parts of it get too hot while the other parts are coming to temp.

Nottingham claims a high attenuation. But I've never used it so I don't know what is high to them. Also it's ideal fermentation range of 10 - 22°C (50 - 72°F) seems to put your conditions as good for fermentation.

How many packs yeast into how much wort? Dry yeast isn't it, then didn't they have a best by date on them?

They do seem to stress storing the yeast below 4C° (39°F) which is lower than the high end of the range that other yeasts give.

 

[lautzki]

When you check your mash temps are you checking in many places or just a few. Since you said that you had trouble with another brew and different yeast then I'd think something other is up than just a yeast issue.

And perhaps if you are having to apply heat to your mash, you might be letting parts of it get too hot while the other parts are coming to temp.

Nottingham claims a high attenuation. But I've never used it so I don't know what is high to them. Also it's ideal fermentation range of 10 - 22°C (50 - 72°F) seems to put your conditions as good for fermentation.

How many packs yeast into how much wort? Dry yeast isn't it, then didn't they have a best by date on them?

Thanks for the reply. When I check the mash temp, I stir the mash thorougly before submerging my thermometer in. I did pulse heat it once from 64c to 65c during the mash, but I was stirring constantly. In retrospect, this was probably unnecessary.

I pitched one packet (11g) on non-rehydrated dry yeast (Lallemand Nottingham) into 24 liters of 1.042 OG wort. Best before date was deep into 2024.

 

[Miraculix]

Just one more data point, I found Nottingham to be one of the less mash temperature sensitive strains. Meaning that attenuation was for me almost the same, even when compared a 62 c to a 70c mash. So your result is even more interesting.

 

[hotbeer]

The Lallemand pitch calculator would rather you have pitched more yeast by about tad more than 3 grams. I'd have probably used two full packets.

RESULTS

---

Yeast needed: 14.1 grams

Pitch rate: 0.6 g/L

500g packets required: 1 packet

11g packets required: 2 packet
https://www.lallemandbrewing.com/en/canada/brewers-corner/brewing-tools/pitching-rate-calculator/
Overpitching makes up for not knowing if the yeast endured any high temps during storage or shipping prior to getting into your control.

Of course that doesn't account for the other batch you did pitch two packs and still say you had low attenuation.

 

[lautzki]

Just one more data point, I found Nottingham to be one of the less mash temperature sensitive strains. Meaning that attenuation was for me almost the same, even when compared a 62 c to a 70c mash. So your result is even more interesting.

Oh, that's.. peculiar. It must be something with the yeast, nutrients/oxygenation or unconverted starches from the flaked barley. Or a combination of them all. Thanks for the insight!

The Lallemand pitch calculator would rather you have pitched more yeast by about tad more than 3 grams. I'd have probably used two full packets.

RESULTS

---

Yeast needed: 14.1 grams

Pitch rate: 0.6 g/L

500g packets required: 1 packet

11g packets required: 2 packet
https://www.lallemandbrewing.com/en/canada/brewers-corner/brewing-tools/pitching-rate-calculator/
Overpitching makes up for not knowing if the yeast endured any high temps during storage or shipping prior to getting into your control.

Of course that doesn't account for the other batch you did pitch two packs and still say you had low attenuation.

That crossed my mind as well. I'm actually starting to lean towards this possibility. Just need to pitch enough yeast and oxygenate properly next time.

 

[hotbeer]

From Lallemand... (and most every other dry yeast supplier)

• Easy to use by rehydrating or pitching dry directly into the wort
• Aeration is not required for the first pitch

https://www.lallemandbrewing.com/en...y-yeast-for-quality-consistent-fermentations/

 

[Pennine]

How does it taste?

 

[GoeHaarden]

Oh, that's.. peculiar. It must be something with the yeast, nutrients/oxygenation or unconverted starches from the flaked barley. Or a combination of them all. Thanks for the insight!


That crossed my mind as well. I'm actually starting to lean towards this possibility. Just need to pitch enough yeast and oxygenate properly next time.

I use Nottingham nearly exclusively in my ales and I have never (yes, I said "never") had it under-attenuate. Its a beast and I don't think I've ever used more than one sachet on anything under 1.075. YMMV

How I use it:
- Packs are always stored in the refridgerator
- I don't oxygenate my wort any more (probably over 6 years now) and I just use the splashing from being pumped into the fermentor as enough.
- I do put a cap full of yeast nutrient in the boil with 15min left.
- I do rehydrate 1 pack in 50-100ml of water that I've brought to a boil in the mircowave and let it cool to about 32c. Pour in sachet and let sit for 15 min, then stir and let sit for another 5 minutes before pitching.
- I ferment it at 60F (15.5c) everytime and it chews through everything. More often than not at stops at 1.011 for me.

I don't think your problem is the Nottingham...

 

[seatazzz]

I use Nottingham a LOT (in all my ales that aren't done with kveik) and have never had an issue with hitting my expected FG. Granted, I do re-use my yeast slurry; but for first pitch of a fresh packet, I give it a vitality starter with some cooled wort for about 30 minutes. Some may scoff, but I think it gives the yeast a bit of a head start. I also ferment about 66-68°; anything cooler than 64° seems to have a longer lag time, and doesn't attenuate well. Almost always completely done and ready to keg after 7 days, with no off-flavors. Lallemand states temperature range of 57°-70°F, so yours may just want some more time. Have you tried warming it up a bit?

 

[GoeHaarden]

I also ferment about 66-68°; anything cooler than 64° seems to have a longer lag time, and doesn't attenuate well. Almost always completely done and ready to keg after 7 days, with no off-flavors.

I haven't found that to be the case and I've never had an issue fermenting at 60F. It still usually finishes in 2-3 days for me at that temp. It really is a workhorse. I don't think I've tried it at it 68F but anything I've tried over 64F hasn't been as clean as 60F for me.

I guess one other thing I do is pitch it at 68 - 72F (where-ever my chiller gets it down to) as my fermenter is getting it down to 60.

Back to the OP; I think you can rule out Nottingham as your issue. But also, IMO, I don't think you have an issue other than what could be measurement error. Don't mistake this comment as one directed at your abilities, but simply at the tools we use and the conditions we use them in. I wouldn't get bent out of shape for anything finishing under 1.016. Remember the predicted Final Gravities are just that, predicted.

 

[jambop]

I haven't found that to be the case and I've never had an issue fermenting at 60F. It still usually finishes in 2-3 days for me at that temp. It really is a workhorse. I don't think I've tried it at it 68F but anything I've tried over 64F hasn't been as clean as 60F for me.

I guess one other thing I do is pitch it at 68 - 72F (where-ever my chiller gets it down to) as my fermenter is getting it down to 60.

Back to the OP; I think you can rule out Nottingham as your issue. But also, IMO, I don't think you have an issue other than what could be measurement error. Don't mistake this comment as one directed at your abilities, but simply at the tools we use and the conditions we use them in. I wouldn't get bent out of shape for anything finishing under 1.016. Remember the predicted Final Gravities are just that, predicted.

I know this is an old thread but it is interesting . One idea I had what if the guy over did the boil and actually has less in FV than he should ? He has a slightly higher OG and more relevantly a greater concentration of non fermentables in the wort at the start of the fermentation ending up with a slightly higher FG due to that ?