Stalled 1007 in Alt beer

[catalanotte]

Looking for some help here with a very stuck fermentation. Made an 10 gal all grain batch of Alt a week ago (1.053 OG, target 1.013 FG). Had a strong start for a few days, then tapered of and quit at about day 5. 3 days of steady 1.030 readings (corrected refractometer, that's not it). I have been brewing for a long time and haven't seen a stuck fermentation like this in a very long time.

Fermentability - No reason to believe that wort is not fermentable, good mash/sparge.
Good water (RO blend) Ca 93.5 Mg 20.3 Na 11.8 Cl 85.4 SO4 65.4 HCO 55.302 with some additional lactic acid in mash and sparge for pH control. Good mash pH 5.45, step mashed at 145/156/168 with complete conversion based on iodine, good temperature calibration. Started mash with a 1qt/lb infusion, stepped up to 1.6 qt/lb with second add, decoction for mash out. Grain bill roughly 60% pils, 30% munich, 9 % cara, and 1% carafa. Better than expected mash/sparge efficiency, made some adjustments to hit target OG of 1.053.

Yeast Health - Pitched about 350 B cells or .65 B/ml/deg P and aerated wort with a good shake (normal process again, always works)
4L starter made with a fresh pouch of Wyeast 1007 and a bit of nutrient, ran for 2 days until completely finished, and mostly cleared. Starter should have produced ~350B cells for 10 gal batch with starter build, this is about .65 B/ml/deg P. A bit under the .75 that many use, but this is max I can get with a one step starter and have good history with this pitch level for ales under 1.060. Might step this up to min .75 next time as a precaution. Decanted (clear spent wort, good yeast cake in bottom of starter) and pitched at 68 deg then dropped to 64 for fermentation. Wort was well aerated by a good shake in the fermenter.

Equipment/Process Changes - Only recent change to process/equipment is the new use of large RO dilutions for alkalinity reduction, used to use lime treated water which resulted in much high mineral content. Could the reduction in some minerals have impacted yeast health in a way I had not seen before with higher levels of trace minerals? Also had excess volume in kettle resulting in very clean whirlpool and transfer, virtually zero trub in fermenter which I do know can be helpful as a nutrient for fermentation. I normally aerate first then pitch yeast. I got ahead of myself and pitched yeast first then aerated - Anyone see a problem here?

How to fix this?
I am not inclined to raise temperature as 64 is already towards the high end for 1007 yeast.
I did try to gently rouse the yeast with a very light stir, no noticeable improvement after about 18 hours.
Tempted to toss in a couple pouches of Fermentis K-97 that I have available to see if that will kick it off.

Open to any suggestion to get this beer across the finish line, and potentially find the bug in the process that got me stuck in the first place.

 

[VikeMan]

Had a strong start for a few days, then tapered of and quit at about day 5. 3 days of steady 1.030 readings (corrected refractometer, that's not it).

Corrected with a refractometer calculator, including the "OG" reading in the combined calculation? Or "corrected" with a brix to SG calculator? I have to ask, because I have seen the latter scenario more than once.

 

[catalanotte]

Corrected with a refractometer calculator, including the "OG" reading in the combined calculation? Or "corrected" with a brix to SG calculator? I have to ask, because I have seen the latter scenario more than once.

Yep, this is a good gravity. Corrected with OG and Brix to give corrected SG. Brix of 10.0 on a 1.053 OG is 1.030

 

[AlexKay]

In terms of tweaking your process I’d look to some sort of supplement of zinc. The yeast don’t need anything else in an all-malt wort, but zinc is key.

For now, if it were me I’d leave it alone and see if it inches down over a week or more. But the K97 won’t hurt anything.

 

[VikeMan]

Which calculator are you using?

This won't completely solve the issue, but using the Sean Terrill formula, with a default Wort Correction Factor of 1.04...

13.63 Brix (1.053 OG)
10 Brix --> 1.024

So perhaps you are stuck at a lower FG than you thought. Also, 11 Brix (along with starting at 13.63) would be pretty close to 1.030. Are you certain that you didn't drop from 11 Brix to 10 Brix somewhere in that stuck period?

 

[catalanotte]

Which calculator are you using?

This won't completely solve the issue, but using the Sean Terrill formula, with a default Wort Correction Factor of 1.04...

13.63 Brix (1.053 OG)
10 Brix --> 1.024

So perhaps you are stuck at a lower FG than you thought. Also, 11 Brix (along with starting at 13.63) would be pretty close to 1.030. Are you certain that you didn't drop from 11 Brix to 10 Brix somewhere in that stuck period?

Been doing this for a long time and the FG is accurate.

 

[VikeMan]

Been doing this for a long time and the FG is accurate.

What calculator?

 

[rmr9]

It looks like you’ve taken a pretty meticulous approach, so this is definitely a bit odd. I know you don’t want to shift the temperature up but this may spur the yeast back into action. Might as well do this before tossing in more yeast I would say.

 

[catalanotte]

It looks like you’ve taken a pretty meticulous approach, so this is definitely a bit odd. I know you don’t want to shift the temperature up but this may spur the yeast back into action. Might as well do this before tossing in more yeast I would say.

I have it split in two separate fermenters. I might try to warm one up and throw an extra pack of yeast in the other. We’ll see which one works better.

 

[rmr9]

I have it split in two separate fermenters. I might try to warm one up and throw an extra pack of yeast in the other. We’ll see which one works better.

Not a bad approach, hopefully it works out for you in both fermenters!

 

[VikeMan]

Welp, I guess if we're going to solve a problem that might not exist, I'll leave ya'll to it. Good luck, Gents.

 

[hottpeper13]

With the alcohol present you should make starters and pitch at high krausen.

 

[catalanotte]

With the alcohol present you should make starters and pitch at high krausen.

I only have Fermentis dry yeast available, which they insist shouldn’t be used in a starter. Any suggestions for getting there with dry yeast?

 

[hotbeer]

I am not inclined to raise temperature as 64 is already towards the high end for 1007 yeast.

Not sure why you wouldn't. 64°F isn't the high end. For Wyeat 1007 it says....

• Temperature Range​

  55-68°F (13-20°C)

Strain: 1007 for German Ale | Yeast & Cultures by Wyeast Labs

And 68°F is only the top of the ideal range, IMO, not the upper limit of that yeast.

However I'm not saying that's your issue for the stalled ferment if it is indeed stalled. Just pointing out that to me 64° doesn't seem like upper limit of anything with disaster happening at one degree more.

I'm thinking that you just need to sit back and give it another week, 2 weeks, 3 weeks or however long it takes.

 

[catalanotte]

Welp, I guess if we're going to solve a problem that might not exist, I'll leave ya'll to it. Good luck, Gents.

@VikeMan You seem to have a ton of knowledge based on other posts and could be helpful here. The SG was a corrected reading using the Brewers Friend calculator. I have used for site years and do side by side comparisons with my hydrometer post fermentation to validate I am getting good results. I always get agreement between my OG, FG, and Brix WRI using this calculator, a temp corrected hydrometer, and a refractometer. I have also checked my hydrometer(s) and refractometer against each other with distilled water and a control solution using DME, checking the range between 1.000 and 1.100. The tools are calibrated and I have validated the accuracy of the 1.04 correction factor that most assume for a wort sugar solution vs pure sucrose. This is why I trust a refractometer reading mid fermentation as a progress indicator. When things are not looking right, I always check the tools and assumptions to make sure I actually have a problem before I go looking for a solution. I understand where you are coming from to question the data before we dive into solutions, but this is not my first rodeo and I am quite diligent in my data. That's why I am so stumped. I rarely get surprises brewing that I cant trace back to an action in the process, which is what I am looking for here.

If you can get passed questioning my ability to get a good SG reading, I'd love to hear you thoughts on the stuck fermentation.

 

[mashpaddled]

If you search here or on google you'll find stalled fermentation is a common issue with this strain. It's a finnicky strain. Giving it more time may be unavoidable but I would raise the temperature, even letting it get up to 70F or a little higher, and rouse the yeast daily.

I like the final product the German/European ale strains produce but they are such a PITA to use.

 

[VikeMan]

@VikeMan You seem to have a ton of knowledge based on other posts and could be helpful here. The SG was a corrected reading using the Brewers Friend calculator. I have used for site years and do side by side comparisons with my hydrometer post fermentation to validate I am getting good results. I always get agreement between my OG, FG, and Brix WRI using this calculator, a temp corrected hydrometer, and a refractometer. I have also checked my hydrometer(s) and refractometer against each other with distilled water and a control solution using DME, checking the range between 1.000 and 1.100. The tools are calibrated and I have validated the accuracy of the 1.04 correction factor that most assume for a wort sugar solution vs pure sucrose. This is why I trust a refractometer reading mid fermentation as a progress indicator. When things are not looking right, I always check the tools and assumptions to make sure I actually have a problem before I go looking for a solution. I understand where you are coming from to question the data before we dive into solutions, but this is not my first rodeo and I am quite diligent in my data. That's why I am so stumped. I rarely get surprises brewing that I cant trace back to an action in the process, which is what I am looking for here.

Using the Brewers Friend Calculator, it's possible to hit your reported numbers (i.e. OG 1.053 and FG 1.030) with an original "brix" of 13.5, and a final "brix" of 10, with a wort correction factor of 1.04.

The same input in Terrill's formulae gives an FG of 1.024. I have compared the various calculators over many years with many batches and can say that Terrill's formulae win, at least for approximating true final gravity of the malt worts I've fermented, and also more than a few batches where others have reported their measurements. It's the reason I continue to use it in BrewCipher in a slightly tweaked way. I know Novotny made some noise about being able to calculate fermenting-but-not-yet-finished gravities better, and it may be that's true. But regardless of calculator, if I had a batch where a refractometer reading was unchanging after 3 days, I'd measure with a hydrometer, in case the wort happened to contain a carb (and protein, etc.) profile that doesn't fit the model well. Did you actually measure this "FG" sample with a hydrometer?

Outside of measurement/calculation, and given your recipe/process, my only suggestion would be to throw fresh yeast at it if a hydrometer still shows a high FG that's not moving. And, yes, you can make a starter with dry yeast, regardless of what Fermentis says. The only thing you lose by doing so is (possibly) sterol reserves, and they can be rebuilt via wort oxygenation, which I wouldn't recommend at this stage anyway.

Regarding your RO water blend (and dilution of minerals), I would not really expect a negative impact from that. And your mash pH and water profile look fine. Yes, zinc is important, but the amount needed is really small, and I've never seen a stuck fermentation that could be attributed to a lack of it. And AFAIK, virtually every natural water source contains some. That said, I do use Wyeast nutrient regularly, mainly as insurance/habit.

If you can get passed questioning my ability to get a good SG reading, I'd love to hear you thoughts on the stuck fermentation.

Well, Sir. I would have been past that quite a while back if you hadn't ignored some of my questions. Perhaps you were punished for the sins of others, but I've been down the "pulling teeth" road with refractometer issues more times than I'd like.

 

[catalanotte]

I'm thinking that you just need to sit back and give it another week, 2 weeks, 3 weeks or however long it takes.

About 24 hrs after a good yeast rousing, it has begun to creep down again after 3 days of steady gravities. Might sit tight till 3 weeks (at 10 days now) and see if it gets there on its own, now that there are signs of life again. If not, I’ll warm it up a bit. Would make for a good finish and clean up anyway.

 

[hottpeper13]

I always make starters from dry lager yeast so I don't have to pitch 2-3 packs. Also I do high grav beers with Notty and those starters kick off way faster then when pitching it dry. Some dry ones are slow to start like BRY97 but when a starter is pitched ,off they go. If I'm not serial repitching, I'm pitching a starter.

 

[balrog]

I would not worry about warming at this point. The primary temp control to concern yourself with is during the growth phase and that's done finished. At this point you should be able to warm to 72F without concern about yeast's ideal temp range.

[Edit: I heard my Mom yelling at me in my head. Had to change "done" to "finished". Sorry, Mom]