Fermentation stuck at 1.033 and 1.044

[Rayomatic]

Just got back into brewing last January after about 15 years. Brewed up a 1.065 batch and it's been bottled already at FG 1.012, no problems. Used a pack of Fermentis Safbrew Belgian Abbaye Ale Dry Yeast for that. Using LME and a bit of sugar.

For the second batch I brewed at 1.054 OG and threw in some dry Lalvin 1118 yeast because I was eager and that was all I had. I figured I'd get started with it and see what happened.
That was Jan 20. It's been stuck at 1.033 since at least Feb 1.
I've heard that the Lalvin 1118 ferments everything, so I was surprised. I heard elsewhere that it's not so well suited to fermenting wort sugars, so on Feb 8 I was racking a 3rd batch (1.066, used cultured Chimay White yeast that seemed to take off, bubbling like crazy), and poured some of the yeast cake from that into batch 2. It seemed to start bubbling a bit, which I took to be a good sign, and is still showing tiny bubbles rising up, but SG is still at 1.033!

What's even worse, batch 3, started Feb 2, is only down from 1.066 to 1.044 today, more than 2 weeks later. Help!

These beers had 7 and 10 lbs LME respectively, and 1lb and 1.5lbs sucrose to up the OG a little. I figured there'd be plenty of nutrients from the LME, so what went wrong? Fermentation temp has been steady between 64F and 68F (moved from cooler to slightly warmer location).

I tried to aerate both batches as best I could after the boil, though I have no special equipment to do so. I topped up about 13-14 quarts of boiled wort with cold water to get the final volumes of 5 gal, so I figured that would aerate enough, especially for the lower OG batch 2.

It's weird because batch 1, my first after 15 years, turned out exactly as expected, and I did everything pretty much the same, same brewing conditions, etc.

I've done some research on methods to unstick fermentation, but there are many that seem specific to certain problems (too little aeration, not enough yeast/repitching, too many unfermentables, etc). Would like to zero in on the problem before starting something drastic.

 

[vtipsy]

Hey, this is probably not helpful but ... did you take those readings using a refractometer? Caus' that would explain it.

 

[Renegade Brewer]

1.065 is a pretty healthy gravity for a single pitch. If you’re using dry yeast I’d suggest upping your pitch rate to 2 or 3 packs to ensure you’re getting enough viable cells to complete the job. If you choose to use a liquid strain make a good starter 48 hours prior to pitching. Using a pitching calculator will help determine your needed pitch rate.

www.mrmalty.com

Also, you mentioned aeration, and that’s a huge factor. Ideally we want 8 liters or volumes of O2 in solution. If you were to try to achieve that by shaking your fermenter you’d have to shake for 4.5 hours to get that much dissolved oxygen into solution. I recommend to new customers an aquarium pump with a hepa filter and diffusion stone. Let it run about 5 minutes, and you’ll be good. You can usually pickup an entire O2 system from your local homebrew shop for about 25.00. For not much more you can upgrade to the sterile O2 can and diffusion stone and hit your wort with pure O2 for about 60 seconds.

Once you increase your pitch rate and increase your dissolved O2 you’ll see your attenuation right where you want it.

Another note, how old was the yeast you pitched? Dry yeast is usually good for about a year if it’s kept cold. Liquid yeast fades at about 6 months and viability will quickly drop. Pitching old yeast is sometimes a problem with shops that don’t care about quality or don’t have a quick turnaround on product. Check your best by dates and mfg dates and ensure your yeast has been refrigerated

 

[Rayomatic]

Hey, this is probably not helpful but ... did you take those readings using a refractometer? Caus' that would explain it.

Nope, old-fashioned hydrometer.

 

[Rayomatic]

Thanks Renegade Brewer and vtipsy for replying. Not sure the age of the Lalvin yeast, but I had used it for some wine back in October when I bought a bunch of packs (hence having some on hand). It seemed fine initially, causing lots of action at the airlock. Same with batch 2, which was yeast from a culture taken from a bottle of Chimay White (2 quarts cultured with LME).

As an update, my Batch 4 which I boiled on Feb 13, OG 1.050 and also pitched with cultured Chimay yeast (started Feb 10) is now down to 1.012. So it's strange that out of 4 batches, 2 ended up stuck at way higher SGs than the other two, even though most conditions were very similar.

I decided to try adding a bit of sugar (3oz per batch) and a bit of yeast nutrient to each batch and stir them up to rouse the yeast. I wish I could control temp but I brew in the basement where it's cool and can't really move the carboys somewhere warmer. Maybe time to invest in some equipment to bring up the temp?

Feb 21: This morning both airlocks were bubbling and there's more small gas bubbles coming up the carboys. Hope that gets things started again.

 

[FermentedCulture]

EC-1118 is a champagne yeast, it cannot ferment maltotriose - one of the main sugars in wort. I've not seen any research but considering it hasn't been domesticated in a brewery it might also struggle with maltose. Wyeast posted a lot of their attenuations in a presentation a while back, their champagne yeast (most champagne yeast is almost identical) produced an attenuation near 60-61%.

A common myth spread on these forums is to use champagne yeast to dry out high gravity beers when they get stuck.

edit: Also note that ec-1118 is killer positive, meaning it produces a toxin which kills other strains sensitive to the toxin. Unfortunately I think most ale strains are vulnerable to this. I've read that kv-1116 can ferment maltotriose. As far as I can see it is not killer sensitive (it's not effected by the toxin) so maybe this might be a choice to finish off the beer. Other choices off the top of my head would be to:

• Blend the beer.
• Add amylase enzymes to the beer to break down the longer chained sugars for ec-1118.
• Add more simple sugars.
• Add a yeast which can ferment maltotriose and if wanted dextrins, which is not killer sensitive.

 

[Rayomatic]

Thanks, FermentedCulture. Had no idea about EC-1118 killing other yeast strains. That might explain Batch 2 and why adding yeast had no effect, but for Batch 3 I used a Chimay yeast only, which worked great for my Batch 4, brewed around the same time. Maybe it's 2 different problems causing stuckness for each batch?
Have added 3oz sugar and stirred to try to rouse the yeast. Will then look into amylase, then another kind of yeast, then finally will consider blending with a lower FG beer to mollify the final sweetness. Will post the results.

 

[Renegade Brewer]

Oxygen and yeast starters will most likely solve this problem. Check your pitch rates using a pitch calculator and make sure to get enough O2 into solution.

 

[Rayomatic]

Would you suggest trying to oxygenate either batch now?

 

[Renegade Brewer]

No no not now. I’m sorry I should have clarified. In future batches ensure to add enough O2 and healthy pitch rates to alleviate this issue in the future.

This batch may just be a loss unless you want to blend it.

 

[Rayomatic]

Right. I know O2 is generally bad, but I'd heard of oxygenation as a last resort if attenuation is less than 1/3 of expected, but maybe even then it's too drastic and might end up worse than just blending with another beer. I'd be ok with blending Batch 2, which has the EC1118 in it and apparently won't benefit from added ale yeast, but reluctant with Batch 3 since it still has so many sugars left (down to only 1.044 from 1.066). Then again, that was my first reading of B3's SG...I assume it's stuck though since it's been 3 weeks in the fermenter already, and should be well lower than that.
In any case since adding sugar+yeast nutrient to both batches and stirring, I'm seeing lots more bubbling in the carboys and airlocks, so I'm hopeful that's gotten things started again. Will keep checking carefully for a few days and take an SG reading once bubbling subsides.

 

[Rayomatic]

Update: One week later, still seeing a decent amount of bubbling in both (formerly?) stuck batches, so I hope the sugar and stirring worked to rouse the yeast. Will report SGs tomorrow.