Yeast cake exploded, overwhelmed temp controller

I recently pitched a Fin du Monde clone onto the yeast cake of a belgian trippel/IPA that I had fermented with Wyeast #3522 (Belgian Ardennes, 65-85F). While the yeast didn't technically explode in terms of a bomb, it did require me putting a blow off tube on our 15 gallon conical with a 10 gallon batch.

Long story short, the heat generated overwhelm our chilling system. I left it Tuesday at 9am and there was zero activity... returned to it Wednesday at 7pm and it was ~87F and vigorously fermenting so it obviously wasn't sitting at that temperature for long (< 36 hours). Should I be worried about any off flavors?

As soon as I saw the problem I immediately pulled it back into range where it reached 67F within a few hours.

I would be concerned....that is a recipe for fruit salad/paint thinner beer. 87F is too hot for that yeast, especially during the early growth phase. I never take it above 75F, and that isn't untill the final few gravity points.

Yet another reason why not to pitch onto your yeast cake...

g-star said:

Yet another reason why not to pitch onto your yeast cake...

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What are the other ones?

I am concerned but am trying to weigh in whether or not the temperature and the time cooperatively made a difference. Considering the reaction is accumulative and exponential in nature, being that it was only at 87F (when it's max is 85F) means that it must have just reached that. SO... obviously there may be an issue but is it that bad?

Double_D said:

What are the other ones?

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Yeah, I'd like to know this too. why is pitching on a yeast cake bad?

Overpitching so you don't get the proper ester profile as the yeast would provide in the budding stage.

So it's dependent on the style and whether you'll get the appropriate flavor and aroma. And not so much like a "you shouldn't do it" thing.

Pretty much. On an ale somewhat, and on a wheat beer and belgian beer styles, you want that flavor from the yeast to come through. If you overpitch them too much, they don't bud and will start fermentation right off the bat. I will generally use 1/3 of the cake and either saver or dump the rest of the yeast.
Now if you are doing lagers, I will use 1/2 of the cake since lagers are beers with minimal yeast derived flavors if done correctly.

That's a good point. Especially for wheat/belgian styles. I usually try to under pitch those and then raise the temp after the first couple days of fermentation. I've had luck with clean american yeasts and moving an IPA onto the cake.

Good information to know.

Agreed but back to the question, so its not nearly a perfect ramp up but none-the-less it seems to be better this occurred on a Belgian than an ale?

Small detail to add: I originally moved this onto the yeast Sunday... Monday no action, Tuesday it was faint (said zero earlier), Wednesday it was vigorous and warm (2 degrees higher than yeasts max), Thursday it was back to the recommended profile temp (per Beersmith at least).



Hey Modo, do you live and brew in Raleigh? I think you're threadstalking me, your sig is exactly what I have going on.

Double_D said:

What are the other ones?

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This thread covers the topic in great detail:

https://www.homebrewtalk.com/f163/why-not-pitch-your-yeast-cake-166221/

Away from the hijacking and back to the simple question. Should I be worried about off flavors???

The answer was yes but my question remains, how bad will they be considering it was only 2F higher than the max of that yeast and that it was only there for <1 day?

tdawg183 said:

I recently pitched a Fin du Monde clone.....

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Unrelated, but care to share the recipe?

rhamilton said:

Unrelated, but care to share the recipe?

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Once I get a response! I don't want to threadjack my own post again.

Just PM me when you get a chance.

tdawg183 said:

Away from the hijacking and back to the simple question. Should I be worried about off flavors???

The answer was yes but my question remains, how bad will they be considering it was only 2F higher than the max of that yeast and that it was only there for <1 day?

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Direct answer: who knows, you may like how it turns or not,depends. The fact remains that science will tell you that off flavors are likely but whether or not the beer will prove to be undesirable is anybody's guess at this point. Trust me you'll know when you take a gravity sample. Some flavors can be cleaned up by the yeast if you leave the beer on the cake for a few weeks. Some flavors never go away.

If you take a sample and don't like the way it tastes then determine what the flavor is and research it's origin, esters, phenols, etc and then determine a course of action and see if additional time will resolve it.

You are looking for a specific answer to a question that has none.