New beer on harvested yeast from slurry ... overpitch ?

[Saxomatic]

I Did a 23l (6gal) 1.056 Scotch ale that ive moved into secondary Monday ( Rockin at 1.018 right now )

Im using WLP028 as yeast ... very pleased !

now here we go with the tricky part

I've done a 23l (6gal) Wee Heavy ( 1.092 OG ) before moving my scotchy... I've carefully keep 700ml (2 1/3) cup of the quite thick slurry, drop on the wee, stir the worth and moved at 63F room and allowed to slowly drop to that temperature ( From 70F )

Tuesday i've walk-in and open the lid ... nice layer of bubblin on top.
I was currious so i've took a gravity sample and BOOM ... 1,030 already !

Is that normal ?
Did i still overpitch ?

Mr Maltys tool suggested 165ml
Thumb rule would ask around 365ml
So i've almost double the thumb rule ... was worried because it's my first try and its a big beer.

Thanx for any input ( suggestions , pointing out failure , etc etc .... )

 

[ColoHox]

Overpitching is not a serious concern at the volumes and time-frames we, as homebrewers, are making. A lot of people underpitch, if they are just pitching tubes or smack packs.

You might have pitched with a higher cell count than recommended by the calculator, but for a high gravity beer like a Wee Heavy, you are just fine. The flip side would have been not pitching enough yeast and the fermentation stalling out, which I would happily avoid by pitching slightly too much yeast.

 

[MrHadack]

I think you over-pitched, yes. Over-pitching can cause the yeast to disrupt their normal life cycle, causing them to not produce new healthy yeast cells. By the end of the fermentation you might have low viability. But is it a problem? Probably not. If the yeast are happy, then it's not a big deal. And it certainly seems like they are happy. I re-pitched from slury for a bock I was making and used 1 cup (8oz) as recommended by Mr. Malty. But that was for a lager. I saw similar results, with a quick drop in gravity and it turned out just fine.

Just curious, why did you go with more than double the Mr. Malty recommendation?

 

[LLBeanJ]

I think it's safe to say that you overpitched. However, given that the MrMalty pitch rate from slurry is a guestimate, the real question is by how much and what will be the result? My guess is that it will be fine. If you had two beers side by side, one overpitched as you did and another with the "proper" pitch rate, you would likely be able to tell the difference, but tasting them alone, maybe not. I wouldn't worry about it.

So, are you saying that it went from 1.092 to 1.030 in 24 hours? If so, that's a pretty big move. By overpitching, I'm guessing the lag time for the growth phase did not occur or was extremely brief. The fact that it was freshly harvested yeast certainly played into the robustness of the fermentation. Normal? I don't know. I suppose it could be given the circumstances (i.e., 3-4x over pitched, fresh slurry).

At any rate, in the future, try to be more accurate in your pitch rates, as they make for healthier fermentations and better beer. That's not to say that you won't get great beer with pitch rates that are over/under the standard, but if you're trying to achieve any degree of consistency then you'll want to be consistent with your pitch rate. When I re-pitch slurry, I generally try to pitch within ±25% of MrMalty's calculated amount.

Btw... what is the "thumb rule?"

 

[Saxomatic]

@MrHadack

Why ? First timer insecurity and didnt want a stalling fermentation like Colohox said ... but now be sure i'll be more aware and confident !

@LLBeanJ

Thanx for your constructive input with that much detail

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

''You can expect around 1 billion active cells in a ml of harvested slurry, depending on how much trub and break material makes it into the fermenter. My counts ranged from 0.5 billion to 2 billion, depending on style brewed and brewery practice. 1 billion is a solid average across a dozen different breweries, professional and amateur
...
Jamil Zainasheff (*Mr Malty ) recommends a modified pitch rate, advocating 0.75 *Billion cells per ml per °P for ale ferments and 1.5 *billion for lagers. My experience tells me the standard rule of thumb - 1 million - is quite sufficient for both ales and lagers. If it makes you lager brewers feel better, pitch at the higher rate. It won't harm anything.''

Well if i did my calculation correctly ( oups )

1,092 = 22 plato * 23l = 506bill ... 506ml ! That should have been the thumb amout

This is WAY over the maltys suggested but less of what ive pourred

In the end i guess i should stick with mr malty calculator +/- 25% like you propose ... its seem to be fair .... How do you play with settings ? I surely can tell how thick my slurry is but im not sure about de % of non-yeast material !

For me Homebrewing is a constant learning curve and im so curious that i read a lot and want to try so many things ... mistakes are steps toward better results !

Should i already move this beer to secondary already to slow down the rest of the fermentation ? Im still at 1.030 with a thick yeast layer on top ?

 

[Weezy]

The yeast aren't going to reproduce because they don't need to. The yeast find their resource limit in the wort and won't perceive an abundance of resources that normally spark reproduction. Without the stressful reproduction part of the yeast's life cycle, you won't see much ester and phenolic production by the yeast. Depending on the yeast and the beer style being brewed, this could be preferable or detrimental.

No need to secondary. The yeast working on the wort are in suspension. The rest aren't doing much at all to influence your beer right now.

 

[LLBeanJ]

About the thumb rule...

Ah, yes. It's all coming back to me now. Thanks.

No need to secondary. The yeast working on the wort are in suspension. The rest aren't doing much at all to influence your beer right now.

+1

Leave it until it is finished, then bottle. No need for secondary.

 

[boydster]

The yeast aren't going to reproduce because they don't need to. The yeast find their resource limit in the wort and won't perceive an abundance of resources that normally spark reproduction. Without the stressful reproduction part of the yeast's life cycle, you won't see much ester and phenolic production by the yeast. Depending on the yeast and the beer style being brewed, this could be preferable or detrimental.

No need to secondary. The yeast working on the wort are in suspension. The rest aren't doing much at all to influence your beer right now.

^^^This, plus add in the fact that there will be far fewer healthy daughter cells if you plan to harvest and reuse this yeast again. You will end up harvesting a lot of aging, scarred cells that will probably not be incredibly healthy.

 

[Saxomatic]

The yeast aren't going to reproduce because they don't need to. The yeast find their resource limit in the wort and won't perceive an abundance of resources that normally spark reproduction. Without the stressful reproduction part of the yeast's life cycle, you won't see much ester and phenolic production by the yeast. Depending on the yeast and the beer style being brewed, this could be preferable or detrimental.

So basically the amount of yeast to pour into the new worth from the slurry also depends on the beer style

does mr Marlty calculator take that point into consideration ?

let say if a beer need lets say 375 bill of cells (from Beersmith or mrmalty) and my beer style are clean and without easter and phenolic production ... i go on par with that amount needed without go overboard to overpitch

if the beer style need those ester and phenolic production, i should lower the amount so it force reproduction of daugther cells ? by how much ?

 

[Weezy]

So basically the amount of yeast to pour into the new worth from the slurry also depends on the beer style

To a limited extent, yes. Some pro shops intentionally pitch low to control fermentation and leave residual sugars for secondary fermentaiton on brett and bugs. You could also, similarly, underpitch in a hefeweizen to get more banana and clove flavor, etc.

does mr Marlty calculator take that point into consideration?

no. he's looking at optimum pitching rates based on unpublished data generated from personal tests. I prefer Kai's more open approach:
http://braukaiser.com/blog/blog/2012/11/03/estimating-yeast-growth/
and his calculator
www.yeastcalc.com

let say if a beer need lets say 375 bill of cells (from Beersmith or mrmalty) and my beer style are clean and without easter and phenolic production ... i go on par with that amount needed without go overboard to overpitch

essentially yes. what truly is an overpitch is unknown. This is all based on empirical data of the performance of a living organism and each yeast type will behave differently in similar conditions.

if the beer style need those ester and phenolic production, i should lower the amount so it force reproduction ? by how much ?

you're better off following the guidelines and the recommended temps for the givne yeast. you'll get the desired effect that way. You can more simply ferment hotter to enhance ester production.

 

[Saxomatic]

well to keep you posted on that wee heavy ... in the end i got that baby on some french oak chip soaked in johnnie Walker for a week ... than bottled ... and now i did by mistake open a beer 3 weeks into bottling and ....

IM damn suprised ... and proud by the results ! Nice caramelization flavor , the oak is light as i wanted and ... no fuzel at all ... i would say that wee will be a dangerous ale ... TOOOOOOOOOOO EASY to drink for a 8.5 %

i can't imagine when it will be at mature stage !