Excessive yeast growth

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PeeBee
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Excessive yeast growth

Post by PeeBee » Mon Oct 09, 2017 9:44 am

I posted another thread covering this issue, but as that's pretty well concluded I'll be a tad more specific in this thread:

I'm using the popular WLP002 yeast but am having issues with it. Not "normal" issues like stopping too early, not getting going ... oh no. It's been going strong ... very strong. It's a 45L batch, OG 1.058, all malt grain in a large conical fermenter rigged with temperature control. I allowed the temperature to rise to just short of 22C (the yeast alone generated this heat easily) before cooling it slowly, currently 15C and SG 1.013. Its on day 4 and in secondary phase; it got through primary phase (1.058 -> 1.016) within 48 hours (wow!).

Going very well. Except. The conical has 3L of dead space between dump valve and racking arm. That space is now chocked with thick yeast. I know it's choked because the racking arm is choked too and that's how I've got to get the beer out. I've cleared it once (yesterday, dumping about 1.5L of yeast sludge), but it is all choked up again. Is this normal behaviour for this yeast?

I did aerate the wort originally with a 90 second blast of pure oxygen (in 45L) through a 2um airstone. I know yeast needs the oxygen for growth and it obviously had enough. Too much? The yeast was cultured for 2-1/2 days in two steps from one pack to give about 0.75 million-cells/ml/degree-Plato in a 45L batch (Brewers Friend calculator using Braukaiser growth model). Over-done?
Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... rDKRMjcO1g
Water report demystified (the "Defuddler"; removes the nonsense!): https://drive.google.com/drive/folders/ ... sp=sharing

Fil
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Re: Excessive yeast growth

Post by Fil » Mon Oct 09, 2017 4:25 pm

in my limited experience its not that abnormal, I have had quite a few brews that have completed primary within 3-4 days just with temp control, a simple sprinkle on of dried yeast and no oxygen injection. (I know i should hydrate first..)

SO with the addition of a larger and thriving population of yeast into a brew with a high o2 content could easily give the brew the boost to perform so well.

the 22c temp may have been a bit high, the whitelabs page on the yeast suggest 20c as the upper temp, the proof however will be in the supping ;)

thankfully you didnt get caught like i did when using a conical for the first few times as i let the yeast build up compact itself and set like concrete plugging the dump valve ..
ist update for months n months..
Fermnting: not a lot..
Conditioning: nowt
Maturing: Challenger smash, and a kit lager
Drinking: dry one minikeg left in the store
Coming Soon Lots planned for the near future nowt for the immediate :(

McMullan

Re: Excessive yeast growth

Post by McMullan » Mon Oct 09, 2017 4:52 pm

That's quick, PeeBee! And might have challenged your temp control? I'm wondering whether you might be over-pitching and oxygenating more than you need? It'll be interesting to see how the beer turns out.

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Re: Excessive yeast growth

Post by PeeBee » Mon Oct 09, 2017 8:57 pm

Fil wrote:
Mon Oct 09, 2017 4:25 pm
in my limited experience its not that abnormal, I have had quite a few brews that have completed primary within 3-4 days just with temp control, a simple sprinkle on of dried yeast and no oxygen injection. (I know i should hydrate first..)

SO with the addition of a larger and thriving population of yeast into a brew with a high o2 content could easily give the brew the boost to perform so well.

the 22c temp may have been a bit high, the whitelabs page on the yeast suggest 20c as the upper temp, the proof however will be in the supping ;)

thankfully you didnt get caught like i did when using a conical for the first few times as i let the yeast build up compact itself and set like concrete plugging the dump valve ..
Thanks Fil. So you for one see nothing daft about my assumptions that I might of over oxygenated and encouraged a bit of a population explosion with the yeast. I'm sure this isn't "normal" for this yeast or I'd have lots of posts to say so (I was angling for a response like that - but this is a popular yeast which I guess it wouldn't be if it had a tendency to cause trouble). I suppose I threw in a very active starter grown to optimum size into a very friendly - for yeast - environment. Liquid yeast and pure oxygen was new to me, so seems I've erred on the side favouring the yeast.

22C was from an interview with the brewer at Fullers (http://www.thebrewingnetwork.com/post1631/). I thought if I've got all the snazzy temperature control, I should give it a go. It all happened so fast it wasn't above 20C for more than a day, and as soon as it hit 22C it got cooled (13C just now, day 4).

If you followed the above link you'd see this is a 1845 clone (again). 1.058 is a bit of a low OG, and that's probably due - I'll have to admit to recklessly making loads of changes to my brewing procedures at the same time - to self-grinding my malt grains for the first time and getting the grind maybe too coarse?
Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... rDKRMjcO1g
Water report demystified (the "Defuddler"; removes the nonsense!): https://drive.google.com/drive/folders/ ... sp=sharing

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Re: Excessive yeast growth

Post by PeeBee » Mon Oct 09, 2017 9:34 pm

McMullan wrote:
Mon Oct 09, 2017 4:52 pm
That's quick, PeeBee! And might have challenged your temp control? I'm wondering whether you might be over-pitching and oxygenating more than you need? It'll be interesting to see how the beer turns out.
I'm used to rapid ferments, but this was a relatively high gravity that I would have expected to have taken 3 or 4 days.

The temperature control was up to it. It's just a few (7) turns of PVC tube around the fermenter a fed from a chiller's (Maxi 310 clone) "python" lines.

I had a second method of chilling that was only being tested this time out. It pumps the beer through the chiller's product coils ... via the racking arm which got itself bunged up with rampant yeast. The pump was looking pretty sick (needless to say nothing was being pumped anywhere). Good job I wasn't relying on it for cooling.

All fixed now. The yeast has stopped growing (its ... well stopped doing anything - pretty abruptly too), the excess yeast has been dumped out of the fermenter (I've got jugs of it - for bread-making perhaps?) and the recirculating pump is happy now its been freed of that biological onslaught. The new cooling has the beer down to 12-13C.

I'll sit back and come up with a somewhat different plan for next time. I'm not abandoning the yeast because (1) no-one has suggested the yeast is a well known uncontrollable monster, and (2) I've got two more packs of it in the fridge.
Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... rDKRMjcO1g
Water report demystified (the "Defuddler"; removes the nonsense!): https://drive.google.com/drive/folders/ ... sp=sharing

McMullan

Re: Excessive yeast growth

Post by McMullan » Mon Oct 09, 2017 9:37 pm

22*C is way too high for most English strains. 16-18*C suits most, unless you're culturing a starter.

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Dennis King
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Re: Excessive yeast growth

Post by Dennis King » Mon Oct 09, 2017 9:46 pm

This is my house yeast, I pitch and 18c then leave it alone, no rousing no oxygen. It's never let me down yet.

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Re: Excessive yeast growth

Post by PeeBee » Tue Oct 10, 2017 12:14 am

Dennis King wrote:
Mon Oct 09, 2017 9:46 pm
This is my house yeast, I pitch and 18c then leave it alone, no rousing no oxygen. It's never let me down yet.
Just checking that interview with the Fuller's brewer and the temperatures are quite different to what I've written down, don't know where I got them. But I couldn't "leave it alone". I pitched at 19C and then was applying cooling to keep it under control. I eased off cooling to and the temperature climbed to 21.4C where upon I stuck the cooling on quite a lot. Without cooling the temperature would have skyrocketed.

The temperatures from the interview were: Pitch at 17C, allow rise to 20C, cool to 18C. Then cool to 6C for a few days. I'm not far enough off that to be unduly worried.
Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... rDKRMjcO1g
Water report demystified (the "Defuddler"; removes the nonsense!): https://drive.google.com/drive/folders/ ... sp=sharing

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Re: Excessive yeast growth

Post by Fil » Tue Oct 10, 2017 12:37 am

Yes perhaps it was a bit overpitched and/or oxygenated, but if that has had any detrimental impact is yet to be seen/tasted, Im not surprised by the way it took of because of the large pitching population and high o2 saturation along side the warmer temp..

i will keep the digits crossed this end (not thats its needed im sure) for a smashing brew when ready to quaff. If its too fruity/ or has a hint of fussels then keep the chilling ramped up next time, tbh im not sure what the negative effects of overpitching in a rich o2 wort could have off the top of my head, i will have to go n check that out now. But i dont think there is a huge crossover with the expected risks of fermenting warm?? .
ist update for months n months..
Fermnting: not a lot..
Conditioning: nowt
Maturing: Challenger smash, and a kit lager
Drinking: dry one minikeg left in the store
Coming Soon Lots planned for the near future nowt for the immediate :(

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Re: Excessive yeast growth

Post by PeeBee » Tue Oct 10, 2017 1:43 am

Fil wrote:
Tue Oct 10, 2017 12:37 am
Yes perhaps it was a bit overpitched and/or oxygenated, but if that has had any detrimental impact is yet to be seen/tasted, Im not surprised by the way it took of because of the large pitching population and high o2 saturation along side the warmer temp..

i will keep the digits crossed this end (not thats its needed im sure) for a smashing brew when ready to quaff. If its too fruity/ or has a hint of fussels then keep the chilling ramped up next time, tbh im not sure what the negative effects of overpitching in a rich o2 wort could have off the top of my head, i will have to go n check that out now. But i dont think there is a huge crossover with the expected risks of fermenting warm?? .
I think you're right, over-pitched and over-oxygenated. But the pitch rate came out of a calculator (Brewer's Friend) so according to that it was pitched just right. And I really struggled (failed) to find guidance on using oxygen - the best I could find was 1 minute at 1 litre per minute into 25 litres wort. But I've got 45 litres, my flow meter was yet to turn up (went with bubbles just breaking surface) and in the absence of any useful advise guessed at a 90 second burst. Is that over-oxygenated? Temperature was certainly too warm, or warmer than intended (I've traced this to something I was reading two years ago), but only by less than 2C for about 12 hours.

Might not be fruity enough, apparently growth uses he same intermediaries as ester production and as there was undeniably lots of growth I guess that suggests fewer esters (how boring, I like the esters).

But this is all academic, I've used Simpsons malt (especially the amber malt) like two years ago. Last year I used my usual supplier and Warminster malt. The effect that had on flavour eclipses any mucking about with the yeast.
Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... rDKRMjcO1g
Water report demystified (the "Defuddler"; removes the nonsense!): https://drive.google.com/drive/folders/ ... sp=sharing

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Re: Excessive yeast growth

Post by orlando » Tue Oct 10, 2017 7:22 am

I've noticed "over pitching" that yeast can lead to much higher attenuation than usual. Has fermentation finished, what %? As you've already started cooling I also wonder if you have allowed the yeast enough time to clear up acetaldehyde. Beer may need a few weeks of conditioning to really come good. Interesting to learn of how the flavour changes as you start drinking it.
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Re: Excessive yeast growth

Post by PeeBee » Tue Oct 10, 2017 10:37 am

orlando wrote:
Tue Oct 10, 2017 7:22 am
I've noticed "over pitching" that yeast can lead to much higher attenuation than usual. Has fermentation finished, what %? As you've already started cooling I also wonder if you have allowed the yeast enough time to clear up acetaldehyde. Beer may need a few weeks of conditioning to really come good. Interesting to learn of how the flavour changes as you start drinking it.
Oh aye, its stopped. A very brief slow down then abrupt stop. Attenuation 76% which is well high for this yeast (published top end 70%) so that supports your observations for "over pitching" (gives an ABV of 5.8%, not far short of intended despite low mash efficiency). Over oxygenation might well encourage aldehydes (and fusels) at the expense of ester production, but the over pitching might negate that: (White Labs video https://www.youtube.com/watch?v=2vELwUs ... e=youtu.be, about half way through). The warmer temperatures might increase fusel production and esters. All six of one, half dozen of the other, impossible to judge what might happen, or even if I could notice the differences.

The beer wont be broached until Xmas.

Sort of gives the answers I was looking for a few weeks ago, but in a more dramatic way than I expected: How long to inject oxygen in a 45L batch (probably 60 seconds like recommended for 25L, and really, does one even need that much?). Also I should treat these "pitch calculators" with plenty of caution; they all seem to estimate well high. And if some figures seem odd, double check the source (relating to my conviction I needed to increase temperature to 22C when the only source I can find suggests 20C - the schedule used by Fuller's and as it's a Fuller's clone I'm brewing...).
Last edited by PeeBee on Tue Oct 10, 2017 3:02 pm, edited 1 time in total.
Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... rDKRMjcO1g
Water report demystified (the "Defuddler"; removes the nonsense!): https://drive.google.com/drive/folders/ ... sp=sharing

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Re: Excessive yeast growth

Post by MTW » Tue Oct 10, 2017 12:29 pm

Useful link there. That's the first time I've heard that increased pitching rate can increase ester formation, rather than reduce it! (19m50'') Then again, I've probably forgotten more than I've remembered from the Yeast book.
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Re: Excessive yeast growth

Post by McMullan » Tue Oct 10, 2017 3:09 pm

Over pitching is usually not a problem for home brewers, but adding lots of healthy yeast and lots of O2, it is a possibility. The risk is diverting C away from ethanol production to favour biomass production. This can increase the level of higher alcohols, which, if converted to esters, can amplify the ester profile. If the yeast bomb out too soon, it might leave an unbalanced level of higher alcohols, detectable in flavour and aroma.

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Re: Excessive yeast growth

Post by PeeBee » Tue Oct 10, 2017 5:59 pm

McMullan wrote:
Tue Oct 10, 2017 3:09 pm
Over pitching is usually not a problem for home brewers, but adding lots of healthy yeast and lots of O2, it is a possibility. The risk is diverting C away from ethanol production to favour biomass production. This can increase the level of higher alcohols, which, if converted to esters, can amplify the ester profile. If the yeast bomb out too soon, it might leave an unbalanced level of higher alcohols, detectable in flavour and aroma.
Okay, you can probably answer the question I've been trying to get an answer to for weeks:

What's enough O2?
Cask-conditioned style ale out of a keg/Cornie (the "treatise"): https://drive.google.com/file/d/0BwzEv5 ... rDKRMjcO1g
Water report demystified (the "Defuddler"; removes the nonsense!): https://drive.google.com/drive/folders/ ... sp=sharing

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