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Belgian dark strong: yeast not hungry enough?

Mashing
#1

OK, so on 12/18 I brewed a belgian dark strong. Grain bill was:
11lb Pilsner
1.5lb caramunich
.25lb special B
3lbs of Agave Nectar (let’s try something new)
WLP500 (yeast cake)

I mashed at 148*F for 90 minutes (my old thermometer could have been off by a few degrees, but calibrated beforehand) and then boiled for 90 minutes. My target gravity was 1.086 and I was just shy of that.

I fermented at 65F for about 2 weeks, then raised the temp to almost 70F for nearly a week.
I pitched yeast from a Belgian Dubbel(starter made) that I transferred that same day. That beer did not finish quite as low as I wanted…1.017 instead of ideally 1.012 or so.

So now the problem. Tonight, more than 3 weeks after fermentation started and over a week after my krausen fell I went to transfer the Dark Strong to secondary. Of course, AFTER I siphon it over, I check my gravity and I’m at 1.045!!! To help this thing along I even had swirled the carboy a few times after the strong fermentation phase & once the Krausen was starting to drop to encourage the yeast to keep working.

Now…what on earth do I do? I was going to wash and save this yeast anyways, so I still have it. I am getting the nice belgian aroma from the yeast. Should I pitch the yeast in there again, buy more belgian yeast, pitch some T-58 or US-05? Champagne yeast or some wild bugs?

Anything to knock this thing down. Or, am I Sh!t out of luck?

#2

What are you measuring gravity with?

#3

A Hydrometer. I also just got a refractometer too. I used both methods this time for grins and giggles. Used Sean Terrill’s spreadsheet for the refractometer adjustment.

#4

At that level of attenuation in your BDS I’d say you have a serious yeast health issue. I didn’t do the math but you only fermented 40 gravity points so you’re probably only at 5% alcohol. You probably should have started ramping the temperature up sooner but I wonder if you are not using enough oxygen prior to fermentation. I would not save this yeast because you’re just asking for more of the same. Start over with a new starter and check your starter size, oxygen amount, and temperatures.

In terms of solving your current problem, I’d suggest making a pint starter with either dry yeast or liquid yeast and adding it at high krausen. That should help to drag the gravity down though you may not get as low as you’d like. You can always do bugs later if that doesn’t work but you have a ways to go and might get more wild character than you want at this point.

#5

[quote=“JLap”]At that level of attenuation in your BDS I’d say you have a serious yeast health issue. I didn’t do the math but you only fermented 40 gravity points so you’re probably only at 5% alcohol. You probably should have started ramping the temperature up sooner but I wonder if you are not using enough oxygen prior to fermentation. I would not save this yeast because you’re just asking for more of the same. Start over with a new starter and check your starter size, oxygen amount, and temperatures.

In terms of solving your current problem, I’d suggest making a pint starter with either dry yeast or liquid yeast and adding it at high krausen. That should help to drag the gravity down though you may not get as low as you’d like. You can always do bugs later if that doesn’t work but you have a ways to go and might get more wild character than you want at this point.[/quote]

Yea, attenuation is in the crapper. It does make sense to say that the yeast are under the weather. Not sure what from, because I used a starter on the previous beer, which tastes quite good eventhough it didn’t finish as low as I had planned on.
If I add more yeast, how I can actually even introduce oxygen this late in the game without ruining the beer. Yum…cardboard. :frowning:

#6

Dang, I was hoping those were refractometer readings…that would put your beer right at about 1.018. Sounds like yeast pitched wasn’t healthy…Or something cosmic that I’d never think of.

#7

I have the best luck with WLP500 when ramped up to about 76-78 over a week. Pitch in the mid-sixties and ramp up just after peak fermentation determined by the slowing bubbles in the air lock.

#8

I think your best bet is to make a large starter with fresh yeast, and pitch it at high krausen. IF you have enough healthy cells from a well oxygenated starter (Ideally stirplate, but even regular shaking will do the trick), you might be able to kick off a new ferementation. I’d try a different strain.

#9

Would you suggest using another belgian strain? I already have that nice aroma from the WLP500 and I can get a litle phenols / ester in the flavor too.

What about pitching some rehydrated dry yeast? T-58 or some neutral champagne yeast? Basically just to ensure it finishes?
Also, I am assuming there are still sugars in there to be consumed given only a 40 point drop, but should I add any other fermentables?

#10

I would not use simply rehydrated yeast (I have tried that before and it didn’t work).
I think you want a small very active fermentation that will then take over and dominate your underattenuated beer. That is why I suggest pitching at high krausen.

I would use a belgian strain if you had it. I don’t like champagne yeast in beer so that would not be my choice.

#11

How far off did you say that thermometer was? High or low?

#12

The old thermometer was High. My target mash temp was 148. I calibrated before my brew session, but there is a possibility that mash temps reached 155*F, which is how far off it was prior to calibration. Even at that temperature it should get down lower than I am now.

#13

[quote=“Wahoo”]I would not use simply rehydrated yeast (I have tried that before and it didn’t work).
I think you want a small very active fermentation that will then take over and dominate your underattenuated beer. That is why I suggest pitching at high krausen.

I would use a belgian strain if you had it. I don’t like champagne yeast in beer so that would not be my choice.[/quote]

OK. Timing shouldn’t matter much right?
If I can get a Belgian strain later today, get a small starter going, and don’t pitch until tomorrow after work, would I see problems considering I racked off that unhealthy yeast on Tuesday?

#14

I wonder what the sugar profile is of the Agave syrup.
Or if it contains preservatives that retarded/inhibited your ferment.

#15

[quote=“Scott Miller”]I wonder what the sugar profile is of the Agave syrup.
Or if it contains preservatives that retarded/inhibited your ferment.[/quote]

It is pasteurized, however it is 100% organic agave nectar, no preservatives.

The bottle did say to use less of this syrup vs. using granulated sugar, but is basically for substituting when baking.

#16

Something sure seems odd.
Have any more nectar that you could ferment with 05 and see what happens?

#17

Shit, I didn’t see that you used Agave. I put a pound of it in my latest belgian tripel. Hope that’s not the problem!!

At this point I wouldn’t worry about timing… get the starter going and add it when it’s ready.

#18

Thanks Wahoo. I’ll give it a go with a new yeast & starter.
I don’t think you will run into problems with the agave. I mean, there are craft breweries that use it in their beers. When I decided to do a dark strong I realized I had access to a couple cases of Organic Agave syrup. I did a little looking around and some of the big boys have substituted it for Belgian Candy Syrup.

Scott - I have plenty more Agave, but I don’t know if I can ferment JUST Agave. Seems like the yeast would get bored right? Plus I’m not sure I want to get another experiment going until I found out how this BDS turns out after I drop in some healthy yeast cells.

#19

I think you have a stalled fermentation due to the large amount of simple sugars in the wort. The yeast chomped on the agave and when it was gone, they stopped eating. I think it would have been best to add the agave as a kicker in increments of 1 Lb.

I think the best course of action now is to pitch an actively fermenting starter as suggested.

#20

I had about 17.5% of sugar as the “grain bill” . I don’t recall where I read it, but I thought it was acceptable to go all the way up to 20% of the recipe with sugars in a dark strong.

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