High gravity fermentation woes

So 2 weeks ago I brewed a 10 gallon batch of a Belgian quad with an OG of 1.108. I split the batch into 2, 7.9 gallon primary fermenters using 2 separate yeast strands. 1388, and 1762. I aerated them with pure oxygen for 4 minutes each. Each fermenter got a quarter gallon yeast starter prepared 3 days ahead of time. To be honest I did not know our OG would be this high because I was not using brew software at the time. Fermentation was violent to say the least for the first 8 days or so.

I assumed two weeks in the primary should be enough for any ale yeast to finish its business so I just went down to my basement to rack these monsters to secondary and to take gravity. I opened up the 1762 and began transferring into the carboy. After about 1 gallon had transferred i checked the gravity.

1.045.

Realizing my critical error, I quickly transferred everything back into the primary and resealed it. Right now I am worried that my yeast are crapping out on me so I am wondering what should be my next course of action. Do I wait another week or two? Should I pitch some high gravity yeast to clean up? Am I being overly paranoid? This is my first truly high gravity beer attempt and I am thinking my yeast starter was perhaps not large enough to create a viable yeast population to finish the job. I could settle for a FG that is a little too high... but this thing is a sugar bomb.

The temperature in my basement varies between 67 and 69 degrees so it should be ideal conditions for ale yeast to thrive.

Yeah, wait another couple weeks, at least. Big beers take quite a bit of time to finish. Yes, you are being over paranoid.

You will probably need to wait at least about a month more, give or take, to have complete fermentation. Don't settle on a FG that is too high; rouse the yeast occasionally to ensure complete fermentation.

By rousing the yeast do you mean stirring the cake back into suspension? Thank you for the response.

Vertra said:

By rousing the yeast do you mean stirring the cake back into suspension? Thank you for the response.

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Just swirl the buckets to get it back in suspension. How much sugar was in your recipe? I would think ypu'd have gotten more attenuation than that.

What Temp did you mash at?

Mashed at 155 for 80 minutes.

30 lbs Belgian pilsner
3 lbs Belgian Biscuit
2 lbs Belgian Special B
1 lbs Crystal 2
1 lbs chocolate wheat
1 lbs dark candi sugar

2oz target @ 60
2oz Styrian Goldings @ 60

mashed with 12 gallons at 155 degrees, had a 65 minute fly sparge, collected 15.5 gallons.

coypoo said:

Just swirl the buckets to get it back in suspension. How much sugar was in your recipe? I would think ypu'd have gotten more attenuation than that.

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There is a ton of scum on the inside fermenter walls, doesnt this add harshness if it is added back in? Would it not be better to take a sanitized spoon to the cake on the bottom and get it all back up into suspension?

Use a sanitized spoon and stir gently.

you've got 7lbs of specialty malts and your mash temp is rather high for a high gravity belgian. I agree it needs more time, but I wouldn't expect your gravity to go very low. That recipe will leave quite a bit of unfermentables. You may want to add some basic table or corn sugar (about a pound) to help dry it out.

A couple of comments from a different p.o.v.:
1. I've not had big beers take longer to ferment. My BW was 1.102 and fermented down to 1.020 in about five days. Same with my imperial red (1.094) and IIPA (1.092). I'd look to yeast health on this one. How was your starter fermentation? Was it one vial each? Did you check a yeast calculator? 1/4gal starter w/ one vial sounds woefully low.
2. What is the gravity on the other yeast/batch? If it fermented differently, that'd be a key piece of info.
3. The 7# of specialty malt shouldn't be that big a deal: first, it's a 15gal batch (EDIT: collected 15.5gal--did you really boil off 5.5gal to get a 10gal batch?!) so the ratio for 5gal is only about 2.3#; second, biscuit & crystal shouldn't add THAT much!
4. 155 does seem oddly high (I know Lagunitas does 156-8, but that doesn't translate to home systems so well)--maybe that is part of it?

Piratwolf said:

A couple of comments from a different p.o.v.:
1. I've not had big beers take longer to ferment. My BW was 1.102 and fermented down to 1.020 in about five days. Same with my imperial red (1.094) and IIPA (1.092). I'd look to yeast health on this one. How was your starter fermentation? Was it one vial each? Did you check a yeast calculator? 1/4gal starter w/ one vial sounds woefully low.
2. What is the gravity on the other yeast/batch? If it fermented differently, that'd be a key piece of info.
3. The 7# of specialty malt shouldn't be that big a deal: first, it's a 15gal batch (EDIT: collected 15.5gal--did you really boil off 5.5gal to get a 10gal batch?!) so the ratio for 5gal is only about 2.3#; second, biscuit & crystal shouldn't add THAT much!
4. 155 does seem oddly high (I know Lagunitas does 156-8, but that doesn't translate to home systems so well)--maybe that is part of it?

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One smack pack of Wyeast each. They got 3.5 days in the starters.

I havent checked the other one. Whenever I do 10 gal batches the gravity is identical in both, I may give it a check later. I am still getting bubbles in the airlocks.

Yes we use a 20 gallon pot over a pretty intense burner, I can boil off 2 gallons of water an hour no sweat. My efficiency is usually pretty high. I dont like leaving much water in my mash tun if I can help it. The ending volume was 10.5, not 10.

I was not aware the difference between 150 and 155 would affect the fermentables so drastically. When people talk about getting tannins in the 170s, I figured I was playing pretty good ball having a 155 mash.

So 1qt of starter with 1 pack of yeast added to each 5 gallons? That is definitely underpitching for that gravity. You would need at least 2qt with 2 packs of yeast for each 5gal.

Sounds like you under-pitched, mashed too high, and have too high a percentage unfermentables.

These quads really need about 15-20% simple sugar, a mash temp around 148F, and a massive starter. They need to finish dry if you want to get close to the real thing.

I'd add a pound of dissolved sucrose and an actively fermenting starter of WLP099. Stirring the carboy and crossing your fingers ain't gonna work.

@Vetra~ the range of mash temps most used is probably 148-158. Those 10F decide the fermentability and body of your beer to a significant degree. Low end --> thinner & more fermentable; high end --> opposite.

As for the gratified being identical, those are the STARTING gravities. I'm asking about the final gravities... That shows your degree of fermentation.

I wouldn't open it up every time to rouse it. If fermentation is slow, you want not fill the headspace and risk oxygenation issues.

The 'scum' is just yeast. I wouldn't violently shake it, just swirl so the stuff on the bottom gets broken up

I have a red IPA going at the moment. Would pitching the belgian quad onto that yeast cake once the red is done? The yeast in that one is WLP041 Pacific Ale which is notoriously slow, but could it finish the job?

The other option is; I just called my homebrew store and they have one vial of WLP099 that they are saving for me. Trouble is I have 2 5gal fermenters. Is it possible to split one vial between two yeast starters and eventually get enough cells to finish the job or would I have to have a second vial?

Update:

Belgian Strong is currently at 1.040 while the abbey remains at 1.044 - 1.045.
I just stirred them up so hopefully they continue attenuating. Any other suggestions?

Vertra said:

Update:

Belgian Strong is currently at 1.040 while the abbey remains at 1.044 - 1.045.
I just stirred them up so hopefully they continue attenuating. Any other suggestions?

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Re-pitch with an actively fermenting starter of an alcohol-tolerant yeast like WLP099. You're already over 8% ABV...that is toxic to most yeast, so dumping onto a standard ale cake won't help, and the yeast you've used for initial fermentation are already stressed.

It's your best chance to save this beer.

Copy.

Do I need to give it anything else? One person suggested 1lb of table sugar dissolved when I pitch the 099.

The sugar will help dry it out and give the active yeast something easy to ferment right off the bat. That would be my approach.

Ok so I have the 099 and I plan to make a yeast starter in the morning. Only 1 vial was available though and I need to grow 2 starters out of it. How big should the starter be for a beer thats already 75%ish done fermenting?? Keeping in mind the gravity is sitting at 1.040 in the Belgian strong fermenter and 1.045 in the belgian abbey 2 fermenter down from the OG of 1.108, what size yeast starter is recommended for a beer that is already partially fermented?

1 other somewhat related question... When someone says 2 liter starter do they mean the size they started with before fermentation, the size after fermentation but before decanting, or the size after decanting?