Fermentation issue

[Jayf19]

Good day everyone
I want my question to be as thorough as possible and would like to have the input of other experienced brewers. I believe I have a fermentation problem that most likely stems from my mash temperature which I wasn’t able to stabilize during the process, which ultimately might have prematurely denatured the beta amylase enzymes. I’m hoping some of you can confirm or infirm my conclusion.

The recipe. I followed Kal’s Electric Creamsicle NEIPA recipe
Electric Creamsicle (New England Pale Ale)

My yeast was a London Ale III strain with a best before date set in February 2022. Since my recipe called form an OG of 1.052 with 11 gallons sent to the fermenter, I prepared a yeast starter of 2.75L with 263grams of DME to have a culture of roughly 443 billion active cells. Within 12 hours, the yeast had already entered the exponential growth phase. I let the starter on the stir plate for 60 to 72 hours before cold crashing it for 24 hours. On brew day, I pulled the starter out of the kegerator, decanted it and set it aside for the whole brewing process to give a chance to the yeast cells to adapt to room temperature, which was about 5 hours.

The grain used in my recipe was crushed to 0.045”, the mash process was done in a recirculating brew in a bag style system with a PH of 5.26. Unfortunately, my mash temperature, which was to be held at 160F for 90 minutes ended up ranging from 154F up to 164F. The rest of the brew process was completed without any inconveniences, although I did end up with 9.8 gallons of wort rather than 11 gallons. In any case feel free to question any steps that I did not detail if it helps identifying the problem.

My OG was right on target at 1.052. I chilled the wort to 66F, aerated it with Blichmann’s Oxygen Flow Regulator set to 1L of pure oxygen for 2 minutes with a .5-micron stone, pitched the yeast and my Tilt Pro and set the fermenting bucket in my fermenting room (repurposed refrigerator). My fermenting room was set to hold a steady temperature of 68F during the exponential growth phase, which has not been in issue.

Here’s a breakdown of the timeline of my fermentation:

• Day 1
  • Lag phase: 0 to 11 hours; ending gravity of 1.049
  • Exponential growth phase started at the 11-hour mark
• Day 2
  • Dry hopped first addition at the 31-hour mark
  • Exponential growth phase ended at 37 hours (lasted a total of 26 hours); ending gravity of 1.024
  • I caught a mild blow-off at the 37-hour mark and installed a blow-off tube before it could create a mess. Ironically, this also coincided with the stalling of the fermentation.
• Day 3
  • 37 hours to 61 hours; gravity still at 1.024
  • Although there is still a high krausen, there is no airlock activity and no changes in the gravity, which was confirmed through both the Tilt Pro and a manual hydrometer reading.

I know 3 days is considered early in the fermentation process, but I’m 10 points shy of my final gravity, and I know by experience that it won’t be dropping much more after entering the stationary phase.

Anyone has thoughts over what went wrong?
Anyone has experience with denaturing beta amylase enzymes too early?

 

[VikeMan]

That grain bill (and lactose addition) is not really very fermentable, particularly at the recipe's target mash temp of 160F. I'd say an expected FG of 1.014 is quite ambitious. When I pop the grain bill (plus one lb lactose), yeast strain, mash time (90 minutes), your intended mash temp (160F), and an OG of 1.052 @ 9.8 gallons into BrewCipher, I get a predicted FG of 1.020. So, IMO this was probably never going to be a 1.014 FG beer.

Compound that with a mash temp that may have reached 164F, and I'm not at all surprised the FG is only down to 1.024 at this point. That said, I also wouldn't be surprised if it dropped another point or two. I would never assume that it's done just because you're not seeing airlock activity.

 

[hotbeer]

I'd just wait it out. Worrying won't make it better and futzing with it might make it worse. Wait the 2 weeks or what ever the recipe suggested or whatever your normal time for fermenting is and then start paying attention to the SG.

I don't have a tilt for my fermenter, so I wait until the 2 week mark and my beer starts looking clean. If it doesn't look clean enough, I'll let it go without taking an SG until it does. 7 weeks is the current record holder for one of my beers for being in the primary and it's a great tasting ale and very clean.

I don't want beers to take that long, but some of my beers do. I'm finally getting around to using other yeasts and the current beer in the fermenter with us-05 looks very promising for finishing earlier than 2 weeks.

Curious about why your mash temp was supposed to be 160°F. That seems high. But I haven't looked at beers that might require such a high mash temp. Usually 160°F is my strike water temp and I mash at or below 154°F. Though I've had some spikes when I didn't control temps well.

 

[Jayf19]

That grain bill (and lactose addition) is not really very fermentable, particularly at the recipe's target mash temp of 160F. I'd say an expected FG of 1.014 is quite ambitious. When I pop the grain bill (plus one lb lactose), yeast strain, mash time (90 minutes), your intended mash temp (160F), and an OG of 1.052 @ 9.8 gallons into BrewCipher, I get a predicted FG of 1.020. So, IMO this was probably never going to be a 1.014 FG beer.

Compound that with a mash temp that may have reached 164F, and I'm not at all surprised the FG is only down to 1.024 at this point. That said, I also wouldn't be surprised if it dropped another point or two. I would never assume that it's done just because you're not seeing airlock activity.

That sums up my thought process as well. I was a bit skeptical about the recipe at first (grain bill, mash temp), but mostly in my own ability to pull it off.

I'd just wait it out. Worrying won't make it better and futzing with it might make it worse. Wait the 2 weeks or what ever the recipe suggested or whatever your normal time for fermenting is and then start paying attention to the SG.

I don't have a tilt for my fermenter, so I wait until the 2 week mark and my beer starts looking clean. If it doesn't look clean enough, I'll let it go without taking an SG until it does. 7 weeks is the current record holder for one of my beers for being in the primary and it's a great tasting ale and very clean.

I don't want beers to take that long, but some of my beers do. I'm finally getting around to using other yeasts and the current beer in the fermenter with us-05 looks very promising for finishing earlier than 2 weeks.

Curious about why your mash temp was supposed to be 160°F. That seems high. But I haven't looked at beers that might require such a high mash temp. Usually 160°F is my strike water temp and I mash at or below 154°F. Though I've had some spikes when I didn't control temps well.

I like to be proactive in my brewing approach and understand what's going on in the various steps. I'm not "worried" about it, but I am aware that there is something going on now. This automatically triggers my troubleshooting mind on. My troubleshooting mind is thinking of adding simple sucrose or oligosaccharides to help make the remaining wort more fermentable.

Excerpt from Kal on a similar recipe using the 160F mash temps : " To avoid drying out the beer too much, the single infusion mash temperature was raised from 152F to 160F and we use a healthy dose of Carapils or Carafoam (1.4-2.9L) to replace some of the Domestic 2-row (1.8-2L) and Maris Otter (2.5-4L) base malts. This malt helps raise the final gravity as this malt produces mostly unfermentable sugars. The higher mash temperature also helps ensure we end up at the target gravity we want (1.014). Too low a final gravity and the beer may taste overly thin, a common problem with lower alcohol version of beers where nothing but the amount of malt is modified. When making lower ABV versions of your favourite beers you want to re-assess the percentages used in the grist and possibly swap out some base malt for unfermentables."

 

[VikeMan]

My troubleshooting mind is thinking of adding simple sucrose or oligosaccharides to help make the remaining wort more fermentable.

Adding simple sugars will boost the ABV, but it won't make the rest of the wort (i.e. the original wort components) more fermentable. It will affect FG slightly, because alcohol is less dense than water.

Also, if you;re going to add sugar, add sucrose or dextrose. Many oligosaccharides are not fermentable (and where would you get them anyway?).

 

[jrgtr42]

Yeah, I'm thinking the mash temp was too high to get to a 1.014 FG.
I don't know if the author was correct in that, but speaking for myself, I target strike water temp of 160 to settle mash temp around 152 (5 gallon batches, usually 12 - 15lbs grain)
I get wanting some unferemtned sugars, but I'd think a 155 mash would leave plenty.

 

[Jayf19]

Adding simple sugars will boost the ABV, but it won't make the rest of the wort (i.e. the original wort components) more fermentable. It will affect FG slightly, because alcohol is less dense than water.

True, I was thinking more in the lines of trying to find a better balance between the sweetness and the ABV. Having a hard time seeing any way to balance this to an acceptable level though.

Also, if you;re going to add sugar, add sucrose or dextrose. Many oligosaccharides are not fermentable (and where would you get them anyway?).

I used the wrong term, I meant an alpha-galactosidase enzyme, such as Beano.

 

[hotbeer]

Have all your beers been too thin for you? How is your water chemistry? That can play a part too.

I'm still not sure I'd want to have a beer that was mashed at 160F for the entire time. Seems like that'd be way to sweet for me. But I'm okay with you being different on that. That's why we have different beers.

Your description of how you didn't hold the mash temp is similar to mistakes I had with mash temps early on varying much like you describe. Probably one of the reasons those beers stayed in the fermenter for over four weeks.

I don't know what SG they ran during the ferment as I don't sample SG till they clean up somewhat and look like they are ready to bottle. But all of those got down in the 1.012 - 1.016 range for OG.

So while you are figuring out what went wrong, just let the current batch be. If you were to add anything to it now, you just add more variables to consider when you finally taste it. Since you have good notes on what you did, then find out what it becomes.

 

[Beermeister32]

If the final gravity doesn’t drop, add 1/2 teaspoon of amylase enzyme to the carboy. Give it a couple weeks before rechecking the final gravity, it converts slowly at fermenting temperatures.