Yeast starter vs yeast cake

[BlackSands]

Interesting result.   The starter beer tastes slightly better than one fermented on a yeast cake.   I'd like to see a similar trial done with starter verses a much smaller quantity of slurry...   

http://brulosophy.com/2018/11/05/yeast-pitch-rate-pt-9-yeast-cake-vs-yeast-starter-exbeeriment-results/

 

 

[Phil_McGlass]

Not a lot in it though.  "5 tasters reported preferring the yeast cake beer, 7 liked the yeast starter beer more, 1 person had no preference despite noticing a difference, and 3 reported perceiving no difference."

[BlackSands]

5 minutes ago, Phil_McGlass said:

Not a lot in it though.  "5 tasters reported preferring the yeast cake beer, 7 liked the yeast starter beer more, 1 person had no preference despite noticing a difference, and 3 reported perceiving no difference."

Yeah, I agree.  And I have a hunch if a more reasonable quantity of slurry was used the difference may then become imperceptible.  That's what I'm hoping anyway because I reuse around 200ml of slurry often!  

[Phil_McGlass]

Ha ha, me too!  On the other hand, if a starter really is better, then we have an opportunity to make better beer! 

[Greenyinthewestofsydney]

Interesting. In all my lagers i have done either with a full slurry or part i have struggled to tell the difference between that and a 3L ish starter. Plus you save 300gm of LDME as well.

[Otto Von Blotto]

Not a great surprise. I've said numerous times that using an entire yeast cake can potentially make the beer blander than pitching around the recommended rate. Probably less potential for it in lagers as they should be pitched with a large amount for best results anyway.

[Phil_McGlass]

Seems to be about acetaldehyde. "To me, the yeast cake beer was dominated by a green apple character reminiscent of acetaldehyde, pushing any malt and hop flavor to the background." I'm guessing that's being released by spent yeast in the yeast cake?

[Otto Von Blotto]

Possibly. I did do a brew on a yeast cake once, I think it was a pale ale. Didn't notice any acetaldehyde in it though. 

[ChristinaS1]

If making a normal gravity ale, pitching onto a whole yeast cake = over pitching = no new cell growth = old, tired yeast.

Don't think it the beer could possibly taste as good as when there is some cell growth and younger cells. 

Cheers,

Christina.

[The Captain!!]

1 minute ago, ChristinaS1 said:

Don't think it the beer could possibly taste as good as when there is some cell growth and younger cells. 

Cause everything is better/healthier as a teenager compared to when you enter retirement. 

Totally agree Christina 

[Greenyinthewestofsydney]

Ale yes. Cake pitch not advisable. For a lager makes no discernable difference. I think old mate brulosophy didnt leave it long enough to clean up myself.

[Worthog]

I' have  been over-pitching harvested slurries to the tune of over 300ml into 1.035 or less wort which typically activated in less than 8hrs (US-05). I did not not realize that the massive eruption of krausen was a basis for bland beer (Pale style); not that I have tasted final bottled outcome but I have a hunch at FG tastings that all is not as well as it could be.

My last batch was a very light slurry pitch of 4th generation US-05 at 100ml only into 22L of 1.031 wort.

The pitch acted much better;

• first pitch into bubbly aerated wort. Stirred in.
• 8hrs; Bubbley aeration gone, sparse spots of low tiny bubbles
• 16hrs; Minute white spots on wort between low tiny bubble groups
• 24hrs; Fully covered wort with minute white cover
• 30hrs; A thickening of white coverage, minute bubbles, total wort coverage except at the very edges of fermenter.
• 36hrs; Growing white coverage to 3mm height.
• 48hrs; White krausen to 1cm height, full coverage.
• 48hrs+ no greater size, but color changing to brown in some areas.

I'm expecting a better FG taste sample on this one, and I'm learning more about the structure of yeast slurry. 

Cheers

[Otto Von Blotto]

1 hour ago, Greeny1525229549 said:

I think old mate brulosophy didnt leave it long enough to clean up myself.

That seems to be a common theme with them. They always seem to do the tasting quite early after the beers are kegged. I like to leave mine at least a week but preferably two, I find they are much better than after a few days.

[Greenyinthewestofsydney]

Yep. Spot on

[Otto Von Blotto]

8 hours ago, Worthog said:

I' have  been over-pitching harvested slurries to the tune of over 300ml into 1.035 or less wort which typically activated in less than 8hrs (US-05). I did not not realize that the massive eruption of krausen was a basis for bland beer (Pale style); not that I have tasted final bottled outcome but I have a hunch at FG tastings that all is not as well as it could be.

 

That's why I try to pitch around the recommended rates as best as I can. Obviously the yeast calculators aren't going to be precise, but ballpark is good enough at home, as long as it's not way under or over it's gonna be fine. These rates I suspect have been developed with flavor in mind as well as fermentation performance overall. With US-05 being quite a neutral yeast, the differences may not be as stark as with other strains, but it's still a good process to pitch around the recommended rate.

[Naughty Corner Brewing]

So I’m going to try doing a harvest and repitch for the first time into my next brew, harvest tomorrow night and repitch Saturday or Sunday.

I just used the calc at brewers friend which suggested 100ml at 10 billion cells per ml. It suggested about a 25 billion cell overpitch.

Just wondering if that density is fairly common though, as I don’t want to underpitch significantly.

Its US05 if that makes a difference?

[BlackSands]

 

 

On 11/7/2018 at 12:10 PM, NewBrews said:

So I’m going to try doing a harvest and repitch for the first time into my next brew, harvest tomorrow night and repitch Saturday or Sunday.

I just used the calc at brewers friend which suggested 100ml at 10 billion cells per ml. It suggested about a 25 billion cell overpitch.

Just wondering if that density is fairly common though, as I don’t want to underpitch significantly.

Its US05 if that makes a difference?

There's a few pitch rate calculators around and they don't all agree with each other, in fact the recommended the volumes of slurry seemed to vary quite significantly between them last time I referred to them.  I don't use them anymore as it's all very imprecise and probably not much better than guessing really but I've settled on around 200-ish ml for my brews which are usually in the OG range of 1.040 - 1.050.  

Given the difference in taste in the exbeeriment was on the threshold of perception it's perhaps not such a big deal for those that enjoy the convenience of pouring fresh wort straight onto the cake from a previous batch.  However, having said that it really wouldn't take much effort to simply to scoop out a good portion of the cake and thus avoid that massive overpitch in the first place.      

 

 

[porschemad911]

I've never used a yeast calculator, not at all interested really. Using a whole yeast cake isn't something I've ever tried, but mostly due to my urge to clean and sanitise things rather than any fear of overpitching.

When I repitch usually I'll pitch 200 - 300ml thick slurry into an average gravity 11l batch which seems to work very well. I will vary a bit, a little less for a low gravity ale and more for a high gravity lager.

Probably the most I have used would be nearly 500ml thick slurry in an 11 batch of a fairly high OG Doppelbock, which came out excellent.

Cheers, 

John

[Otto Von Blotto]

On 11/7/2018 at 9:10 AM, NewBrews said:

So I’m going to try doing a harvest and repitch for the first time into my next brew, harvest tomorrow night and repitch Saturday or Sunday.

I just used the calc at brewers friend which suggested 100ml at 10 billion cells per ml. It suggested about a 25 billion cell overpitch.

Just wondering if that density is fairly common though, as I don’t want to underpitch significantly.

Its US05 if that makes a difference?

Must be basing it on thick slurry, they usually run with a figure like 2-3 billion cells per mL for harvested slurry. A 25 billion cell overpitch won't be an issue though, it's what I usually run with, as I'd rather be a bit over than under, and the yeast calculators aren't precise. Having said that, I reckon it's more accurate with the method I use with building it up in starters than taking fermenter slurry, mainly because the figures in the calculator are based on actual observed growth. While it's still not precise, it's more accurate. Cell numbers in slurry are nothing better than a guess.

If you're simply taking from the yeast cake, about a third or so of it will be enough for the next batch provided the volume and OG are similar to the one the cake came from.

[Greenyinthewestofsydney]

I work on 1.5. Just out of observation by usage of slurry. I think 3 is pushing it for slurry. But yes. Its a guess either way and IMO not advised for an ale. For a lager go for your life.

[Naughty Corner Brewing]

Thanks everyone.

I’d like to get the gear to do some starters, but I think that will be down the road a little.

I collected about half of the cake out of my batch and it’s still separating. I’ll see how it looks in the morning and I might pour off the top into a second jar if it’s settled out enough. I left it about an hour tonight and I might have 10mm of clear beer above the settling trub so far.

Worst case, I have spare packet of us05 if it’s no good come Saturday.

Do I just give it a shake and toss it in?

[Otto Von Blotto]

Yep pretty much. Some guys go to the trouble of washing the crap out so they just get clean yeast but I don't think it's really necessary, just swirl it up and pitch it. As such, I'd leave the beer on top in there so you've got some liquid to swirl it up with.

I prefer clean yeast, but can't be arsed with washing it so I began harvesting it from starters instead of the fermenter trub.