Reusing A Yeastcake

[spudfarmerboy]

Happy new year to all AHB'ers,
Tomorrow I will be brewing a Dr Smurtos Golden Ale. I already have one in the fermenter that is ready to be kegged. I am thinking I will brew and then drop the wort from the kettle into the drained fermenter, with the yeast cake still in there.
Is this a good idea or not, is it worth worrying about when using a dry yeast like S05 that costs about $4.50?
If it is a good idea, when the fermenter is drained of beer, is there anything that should be done to the yeast cake? Is there a need to get the fresh wort onto the yeast cake pronto or not. If there is a time gap between emptying the fermenter of beer and filling the fermenter with fresh wort, how should the yeast cake be stored?
I have never done this before and thought if I have a good, viable yeast cake, it may get the fermentation off to a flying start.
One more thing, the fermenter is crash chilling, would the yeast cake need to be brought back up to around the 20 degree mark before dumping the fresh wort in?
Thank You

 

[Steve@PMF82]

I think that pitching onto yeast cake is overpitching.
I do reuse US05 though, following the ballpark rule of 1/2 a cup of slurry for ales and 1 cup for lagers - 23L batch
I swish all my remaining beer and trub around then pour into sanitised jug, cover and let the trub settle out
over 30mins or so then pour of the yeast into clean jar and reuse within a few weeks - stored in fridge

Its always a good idea to have your yeast at the same temp as the brew your putting it in.

 

[_HOME_BREW_WALLACE_]

Happy new year to all AHB'ers,
Tomorrow I will be brewing a Dr Smurtos Golden Ale. I already have one in the fermenter that is ready to be kegged. I am thinking I will brew and then drop the wort from the kettle into the drained fermenter, with the yeast cake still in there.
Is this a good idea or not, is it worth worrying about when using a dry yeast like S05 that costs about $4.50?
If it is a good idea, when the fermenter is drained of beer, is there anything that should be done to the yeast cake? Is there a need to get the fresh wort onto the yeast cake pronto or not. If there is a time gap between emptying the fermenter of beer and filling the fermenter with fresh wort, how should the yeast cake be stored?
I have never done this before and thought if I have a good, viable yeast cake, it may get the fermentation off to a flying start.
One more thing, the fermenter is crash chilling, would the yeast cake need to be brought back up to around the 20 degree mark before dumping the fresh wort in?
Thank You

I wouldnt really bother IMO, I would be more inclined to re-use a yeast that has just cost $14-15 not a cheap dry sachet, but that is just me. Secondly, I wouldnt drain the kettle straight onto the cake either. The hot temperature will kill your cake (unless you have a chiller).

 

[Fantoman]

Yeah, it works fine. There are a couple of options really...

You can pour out about 1/2 to 1 cup into a sanitized jug, cover with glad wrap, and clean the fermenter, sanitize, fill and pitch which I have done many many times with great success - never had a problem...

You can also pour out the majority of the trub, leaving about 1/2 - 1 cup in the fermenter and refill directly - this works fine as long as the yeast isn't left exposed for any lengthy period, i.e. if you have a cube of wort ready to go and dump it straight in after kegging, etc... have done this a few times and works fine and saves a little bit of time cleaning and sanitizing the fermenter - although I wouldn't do successive brews using this method... The chance of infection is slim as there is a good amount of yeast to take hold straight away.

Either option is not a great idea if you have dry hopped however as the yeast trub has more hop debris that can affect the flavour of the following brew.

Edit: yeah, not directly from the kettle though unless it is chilled before hand to pitching temp!

 

[manticle]

You may find useful information in these links

http://www.aussiehomebrewer.com/forum/inde...?showtopic=3697

http://www.aussiehomebrewer.com/forum/inde...showtopic=29893

You can just pitch straight onto a yeast cake but you will almost undoubtedly be overpitching. I've tried it twice and been rewarded with infections.

I do ocassionally pitch straight onto the dregs of a sour beer but they are a different story anyway.

As for re-using dry yeast - you can. I don't though. I re-use/harvest/store most liquids but just use new dry yeast whenever I need it. I only ever really use US05 anyway.

Something about the increase in bacterial cell count with re-pitching is my understanding of why it's less common with dry yeast. Presumably acid washing (second link) will fix that problem.

 

[SanDiegoBrewer]

definitely re use the cake if it was a clean healthy pitch. You are not over pitching. The best way would be to clean transfer the cake to another container and rinse the yeast with sterile water and remove the trub/dead yeast/ hop matter. there are a few youtube vids on that. then if you can make a good guess on pitching rates you will have a good fermentation and slightly overpitching with that strain wont be an issue.

You may find useful information in these links

http://www.aussiehomebrewer.com/forum/inde...?showtopic=3697

http://www.aussiehomebrewer.com/forum/inde...showtopic=29893

You can just pitch straight onto a yeast cake but you will almost undoubtedly be overpitching. I've tried it twice and been rewarded with infections.

I do ocassionally pitch straight onto the dregs of a sour beer but they are a different story anyway.

As for re-using dry yeast - you can. I don't though. I re-use/harvest/store most liquids but just use new dry yeast whenever I need it. I only ever really use US05 anyway.

Something about the increase in bacterial cell count with re-pitching is my understanding of why it's less common with dry yeast. Presumably acid washing (second link) will fix that problem.

 

[Yob]

then if you can make a good guess on pitching rates

there is also Mr Malty which is a great tool to determine, not guess, pitching rates required for your next brew. There is a re-pitching from slurry section...

http://www.mrmalty.com/calc/calc.html

 

[manticle]

definitely re use the cake if it was a clean healthy pitch. You are not over pitching. The best way would be to clean transfer the cake to another container and rinse the yeast with sterile water and remove the trub/dead yeast/ hop matter. there are a few youtube vids on that. then if you can make a good guess on pitching rates you will have a good fermentation and slightly overpitching with that strain wont be an issue.

I was suggesting dumping the new beer directly on the yeast cake is overpitching. Obviously if you remove the yeast, rinse it and use the correct amount as you suggest then you are not overpitching.

 

[Bribie G]

"Yeast cake" isn't all yeast cells. A lot of it, possibly most of it, consists of cold break and dead yeast "hulls". If repitching ale yeast I prefer to get my sample from the krausen on top of the brew as that's nearly all live yeast, and go from there. To get an accurate measure for how much cake to pitch, I'm seriously thinking of setting up a basic yeast lab as described in the new Yeast book by Chris White and Jamil Z - actually doing a yeast count is straightforward using a 400x microscope and a special counting grid thingo - always fancied one of those new USB microscopes.

How to bore people to death with screenshots of your latest 1469

PS:



Recent cold break experiment, the "cake" in #2 contains nearly all the cold break from a double brew, so you can see the sheer volume of break material you can actually get in yeast cake. Dunno if I'd want to be pitching all that into a new brew.

Edit: Page 168 of the new book goes into what to do with a yeast cake

 

[manticle]

To get an accurate measure for how much cake to pitch, I'm seriously thinking of setting up a basic yeast lab as described in the new Yeast book by Chris White and Jamil Z - actually doing a yeast count is straightforward using a 400x microscope and a special counting grid thingo - always fancied one of those new USB microscopes.

Is this the same Bribie who saw Beersmith akin to a new fandangled fancy pants pant fancier's fancy pant close to a year ago?

I agree though - most of the yeast cake left behind is shit I've deliberately dropped out of my beer. If I can top crop and I remember to do it at the right time, I find it the best, most effective way of re-using yeast (although slurry does work) and almost completely clean of not nice things.

 

[Lecterfan]

Dear BribieG,

take pity on those of us who haven't managed to obtain the new yeast book (the yeastonomicon?) and please lavish us with more tidbits.

In particular: is there any startlingly new info to be found on page 168 (what to do with the yeast cake) compared to what can be found on the net/AHB already? :icon_cheers:

 

[manticle]

There's some great detailed info on re-use, washing and storage of yeast but to type it all would take a long time.

They certainly don't recommend re-using the entire yeast cake and recommend caution if acid washing yeast among other things.

 

[Lecterfan]

Thanks Manticle. I generally use the advice from the 3rd ed. of How to brew - I take about a litre of slurry, shake, pour off, bla bla bla and it seems to work fine. I was more concerned that there had been some radical change where that method was no longer appropriate. I generally pitch within an hour or so of going through the process (frum trub to new brew).

Cheers! :icon_chickcheers:

edit: I end up pitching about 300mls of pre-boiled water that is full of yeast in suspension....the litre is just the starting point.

 

[manticle]

Slightly OT:

Yeast book is more detailed and definitely worth reading and owning.

The main drawback so far (still reading) is that it only ever discusses whitelabs yeasts in regards to liquid yeasts.

Its main author is Mr Whitelabs himself so it's understandable and if its marketting literature then its very, very comprehensive marketting literature - a mention of other yeasts would be welcome though even if the focus was on WL.

Minor criticism - worth every cent I spent on it and I'm less than half way through.

 

[juzz1981]

+1 for Top Cropping

Haven't bothered with harvesting from the yeast cake since.

 

[Siborg]

I was suggesting dumping the new beer directly on the yeast cake is overpitching. Obviously if you remove the yeast, rinse it and use the correct amount as you suggest then you are not overpitching.

What he said

I've done this once before and the taste aint so great. Take a cub of slurry, or top crop, or take a sample and build up a starter from that.

 

[stew.w]

if i'm making a similar beer to the one just fermented, i just swirl the remaining yeast and beer in the fermentor and tip most of it out and then pour the next batch in. works fine for me, been doing it this way for about a year and havnt had an infection.

cheers,

Stewart