Several Brews With Same Yeast Cake?

[bigbird]

Hi, I've got an AIPA in the ferrmenter now (S-05 yeast pitched monday morning). Doing an APA on Friday night, and then thinking of one or two more after that.... all are tripple batches. I rack from primary to secondary and reuse the primary cake. I'm wondering how many you can pump through before yeast mutations and viabillity drops off or any other issues with it....

 

[clean brewer]

Hi, I've got an AIPA in the ferrmenter now (S-05 yeast pitched monday morning). Doing an APA on Friday night, and then thinking of one or two more after that.... all are tripple batches. I rack from primary to secondary and reuse the primary cake. I'm wondering how many you can pump through before yeast mutations and viabillity drops off or any other issues with it....

Ive read brewers doing up to 5, ive only reused the yeast cake twice on most occasions, the look of the fermentor after 2 brews is enough for me... <_<

Also, you should be repitching a brew stronger/darker than the one before.... Probably be best to do some yeast farming from the fermenter after 2 batches and re-pitching onto a stronger/darker brew or washing the yeast that you have farmed....

:icon_cheers: CB

 

[DJR]

US-05 tastes better after a repitch IMO

Micros have been known to use 15-20 generations of pitching with no problems but for $5 a sachet i'd go to 5 tops

 

[white.grant]

I find that the outer limit for many yeasts is about 5-6 generations.

You really don't need to use an entire yeast cake on the same strength brew though, overpitching can really influence yeast flavour profiles and give unwanted results. Just a good cup or so of slurry is all you need to pitched into your next wort. You can then save much of the remainder of the first yeast cake to be used later and then theoretically you've got 5 more pitches of that one as well.

Depending how long you leave the slurry sitting you may want to use a starter to get yeast viability back up to healthy levels.

While most yeasts do seem to give better results on their second and third generations, as CB mentioned, you can go darker/stronger/hoppier but you can't go lighter/weaker.

cheers

grant

 

[Ross]

US-05 tastes better after a repitch IMO

I'm very interested in the theory behind this, as many brewers claim better results with subsequent repitches.
What happens to the yeast to improve it? Or is it possible you've just under pitched the 1st brew?

Cheers Ross

 

[QldKev]

I'm very interested in the theory behind this, as many brewers claim better results with subsequent repitches.
What happens to the yeast to improve it? Or is it possible you've just under pitched the 1st brew?

Cheers Ross

Not 100% sure on the theory but I also think US-05 (1056) is best about the third brew; was just talking to Thunus on the weekend about this. I use about 1/3 of the yeast from the prior batch; ie tip 2/3 out and drop the no-chill ontop of the yeast.

The way I see it,
a) it is either getting a better pitch ratio; meaning the original 12g yeast packet was too small, or a large propotion of non viable cells, or an issue with not rehydrating the yeast prior to pitching.
B) or we have more viable yeast cells, that are hydrated ready to do their yeasty things.
c) the yeast are mutating producing a cleaner beer, less influenced by the yeast esters. (not sure on a second or third brew if possible)

QldKev

 

[bigbird]

Awesome, thanks foy the info guys. Pity I did a big, darker AIPA first.... Might harvest a portion of the yeast to add to the yeast farm. How would I wash the yeast to repitch? Collect some slurry and add distilled water, let it settle and pour off the liquid before pitching?

Also are S-05 and Wyeast 1056 the same strain? is one better than the other?

 

[therook]

Awesome, thanks foy the info guys. Pity I did a big, darker AIPA first.... Might harvest a portion of the yeast to add to the yeast farm. How would I wash the yeast to repitch? Collect some slurry and add distilled water, let it settle and pour off the liquid before pitching?

Also are S-05 and Wyeast 1056 the same strain? is one better than the other?

Check this link out

link

Rook

 

[Fourstar]

I'm very interested in the theory behind this, as many brewers claim better results with subsequent repitches.
What happens to the yeast to improve it? Or is it possible you've just under pitched the 1st brew?
Cheers Ross

Hey Ross, by repitching, (especially of you rinse your yeast) you are selecting the slightly less flocculent and more attenuative yeast. Also by repitching the yeast are acclimitised to your 'brewhouse' if you are pumping out similar ABV and hopping rate styles. by selecting the repitched yeast/older generation, yes it is less 'pure' but the flavour profile of the beer (atleast i find with mine) to be allot better on subsequent pitches from the regeneration of cells accustomed to chewing through beer.

Not 100% sure on the theory but I also think US-05 (1056) is best about the third brew; was just talking to Thunus on the weekend about this. I use about 1/3 of the yeast from the prior batch; ie tip 2/3 out and drop the no-chill ontop of the yeast.

Rule of thumb for pitching rates on bog standard 5% ABV beers~. 1/2 cup of slurry for an ale, 1 cup of slurry for a lager. If you are pitching any more than this you will not get any yeast growth, very few new cells and a lower viability to repitch that slurry again. Not ot mention you miss out on the flavour profiles assoicated with some yeast growth.

Another downside for repitching yeast that has not gone through a growth cycle is you can end up with unatteuative yeast that hang around and haze up the beer.

Cheers.

 

[bigbird]

Thanks for the link rook, and thanks everyone for the info.