Re Using yeast Cake

I have read a lot on the message boards about reusing yeast cake, If im going to brew same beer on same day I bottle/keg and want to re use yeast cake. Can i just pour beer into same fermenter airate and let go, will this be to much yeast and what will the adverse affects be on my taste profile. Also how many times can you do this be for yeast don't want to work anymore. I am just looking for an economical way to reuse some live product, and im lazy.

You can just pour the wort into the same fermenter and let it go to town. It is over pitching a bit but I've never had it affect the flavor. You can only do this once without removing some of the yeast or your fermenter will be several inches deep with yeast. We have a great sticky on yeast washing.

Whether it will be overpitching depends on the gravity of the wort you are pouring on top of the cake. Most likely you will be fine. I do this often and if your sanitation is good, you can re-use yeast 10 times or more though you will want to split it occasionally so you are not massively overpitching. Many excellent brewers feel they get the best beer from yeast that has been re-used 4-6 times.

You will also probably want to do a search for yeast washing. This will allow you to re-use yeast almost indefinately if you maintain a sanitary yeast crop.

Knocking out onto a yeast cake is never a good idea. In the first place, it is - outside of a very, very few specific instances which the homebrewer is unlikely to find - always overpitching.

It is not "a bit".

Overpitching is always detrimental to the beer. I'm not saying it'll taste awful. I assure you, however, that were you to place samples of the exact same beer - one fermented by overpitching and one by properly inoculating the wort - the one properly pitched will taste better. Blind taste tests prove it.

Harvesting yeast is easy. All you need is a sanitized scoop and a couple of sanitized Mason jars. Then you can calculate how much to pitch in your next batch and avoid overpitching into a positively filthy vessel. (Ew.) You can do this in five minutes, and take another five to ten minutes to clean your fermenter. That's not very hard. Harvesting also allows you to pitch your yeast out to many more generations than simply dumping fresh wort into your fermenter.

If a thing is worth doing, it's worth doing properly. It's worth doing to the best of your ability, effort, and means. Knocking out onto a yeast cake not only doesn't really save you anything at all, it also is guaranteed to brew mediocre beer in the vast majority of circumstances.

But if you insist on doing it, don't aerate. It's not necessary.

Have fun!

Bob

Bob said:

Harvesting yeast is easy. All you need is a sanitized scoop and a couple of sanitized Mason jars. Then you can calculate how much to pitch in your next batch and avoid overpitching into a positively filthy vessel.
Bob

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So is it as simple as taking a scoop of the yeast cake and adding it into a sanitized jar to keep in the fridge? If there are no nutrients in the jar for the yeast, will this be a problem for long term storage?

Also, is there anything wrong with using parts of a yeast cake that was used in a secondary which had dry hopping? I doubt that anything outside of getting a little extra aroma would occur, but just wanted to make sure.

Bob said:

Knocking out onto a yeast cake is never a good idea. In the first place, it is - outside of a very, very few specific instances which the homebrewer is unlikely to find - always overpitching.

It is not "a bit".

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Sorry Bob, but pitching onto a yeast cake is fine in virtually all circumstances unless you are pitching a very low gravity wort. Pro brewers I've spoken with pitch on cakes all the time and will only split the yeast after a couple of batches. I think maybe they might know a thing or two about yeast. You might want to do a little research before you throw out an always... no offense.

Six_O_Turbo said:

Sorry Bob, but pitching onto a yeast cake is fine in virtually all circumstances unless you are pitching a very low gravity wort. Pro brewers I've spoken with pitch on cakes all the time and will only split the yeast after a couple of batches. I think maybe they might know a thing or two about yeast. You might want to do a little research before you throw out an always... no offense.

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Just because their pros doesn't make them right. Cell count aside, Pitching onto a yeast cake in a nasty fermentor is just bad practice and it's lazy. all in my very humble opinion of course.:fro:

When they are winning golds at GABF, then they are more right than I am. MHO as well, of course.

I don't get why the fermenter is "nasty", it should be no less sanitary than when the first wort was tossed in unless you are somehow contaminating in the transfer process. Please explain why it's "bad practice". If you are going to go with the 'overpitching' line, please also explain the detriments and when you cross the line to 'overpitching'.

It's not really about whether it is Sanitary or not. Just look at a clean fermentor and then one that just had a beer racked out of it. For me the latter would explain Nasty and Bad Practice.

I just don't see why anyone wouldn't take a few minutes to hold back a proper amount of yeast cake then give the Primary a good scrubbing and sanitizing and then putting your freshly crafted wort into the spotless fermentor. It might take 15 minutes, tops.

But really, at the end of the day, WTF. If it works for ya, have at it.:cross:

Oh, you mean the capitalized: "Nasty" and "Bad Practice", I see... Well, that explains everything...

Thank you!

Really though, it's not about being lazy, and I could give a damn if the fermenter is ugly, as long as it's sanitary. I get better beer from having a big pitch of active yeast.

I think Ray Daniels explains it well in "Designing Great Beers". But, like you said... Do what works for ya.

Lefe21 said:

So is it as simple as taking a scoop of the yeast cake and adding it into a sanitized jar to keep in the fridge? If there are no nutrients in the jar for the yeast, will this be a problem for long term storage?

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Yes, it really is that simple. And yes, there are problems with long-term storage. The harvested yeast should really be used within seven days, tops. If you plan to store it longer-term, wash it.

Also, is there anything wrong with using parts of a yeast cake that was used in a secondary which had dry hopping? I doubt that anything outside of getting a little extra aroma would occur, but just wanted to make sure.

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Don't use the dregs from the secondary. First, as you note there's usually too much non-yeast material. Second, there's not as much yeast in the slurry.

Six_O_Turbo said:

Sorry Bob, but pitching onto a yeast cake is fine in virtually all circumstances unless you are pitching a very low gravity wort. Pro brewers I've spoken with pitch on cakes all the time and will only split the yeast after a couple of batches. I think maybe they might know a thing or two about yeast. You might want to do a little research before you throw out an always... no offense.

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No offense to you, old top, but that information flies in the face of almost two hundred years of fermentation science. I have done quite a lot of research, thank you, and all of it points to me being right. Everyone from Fix to Bamforth to homebrew icons as Jamil support me.

Where's your support?

Speaking as a professional brewer, I cannot imagine the pro dumb enough to suffer this practice in his brewery. The professional small-brewery practice is to harvest yeast from the cone of a conical fermenter and re-pitch a measured amount into the next batch. This practice can, without washing or other more-advanced care of the yeast, be extended to ten or more generations. In professional practice I can get between ten and fifteen generations, depending on strain.

If you truly understood yeast, its life cycle, and the impact of that life cycle on beer, you wouldn't say this sort of thing.

I don't get why the fermenter is "nasty", it should be no less sanitary than when the first wort was tossed in unless you are somehow contaminating in the transfer process. Please explain why it's "bad practice".

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Be glad to. It's nasty because if it's not visibly clean, it's dirty. Good practice means keeping your brewery (or at least your equipment) scrupulously clean. Hell, even Papa Charlie knows that!

A thing is either clean or it is not. If there's a stain on your shirt, it is not clean. If there's mud on your windshield, it is not clean. If there's krauesen glued to your fermenter, it is not clean. Visible soil means it cannot possibly be sanitary. Just ask people who work in operating rooms.

If you are going to go with the 'overpitching' line, please also explain the detriments and when you cross the line to 'overpitching'.

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Be glad to. The two most obvious are off-flavors. First, yeast material in excess quickly leads to autolysis, which has flavor by-products which have very low flavor thresholds. Second, tasters have observed thin beer, beer lacking in body and mouthfeel. Third, suppression of esters. Yeast rely on the growth phase to reproduce enough cells to fully colonize the wort. In that phase, they use malt-based nutrients and the oxygen you provide during aeration to synthesize the components needed to build new cell walls. While they're reproducing they're producing esters. All yeast produce esters, even lager yeast, and all beers benefit from ester production (yes, even lagers). Just because you can't taste as much ester from WLP840 as you can from Ringwood doesn't mean that WLP840 doesn't throw esters! Esters are necessary to beer, theory about "clean yeast" be damned.

When you overpitch the colony doesn't need to reproduce. Thus measurably fewer esters are produced. This, while always detrimental to beer flavor, is more pronounced with certain more flavorful strains, like Belgian strains.

The brewery where I served my apprenticeship was a Ringwood brewery. More than a dozen styles were fermented with Ringwood, including styles like American Pale Ale and Wee Heavy. If you know yeast, you know Ringwood is very flavorful. In order to brew those styles, styles which should have very little detectable esters, we deliberately pitched more than we needed, thus suppressing ester formation. By manipulating the cell counts at inoculation we could produce the same flavor effect as switching strains entirely. GABF, WBC and the late Michael Jackson (not the one with the glove) noted the positive effects of our Good Practice in their appreciation of our beer.

As noted in Brew Like a Monk and other books, some beers benefit from slightly underpitching, because ester production is encouraged. It all depends on what you're trying to do.

I realize I probably shouldn't make blanket statements like "always" or "never". Since, however, in this case I have the fortunate circumstance of being right, I'll stand by it.

Regards,

Bob

Six_O_Turbo said:

Oh, you mean the capitalized: "Nasty" and "Bad Practice", I see... Well, that explains everything...

Thank you!

Really though, it's not about being lazy, and I could give a damn if the fermenter is ugly, as long as it's sanitary. I get better beer from having a big pitch of active yeast.

I think Ray Daniels explains it well in "Designing Great Beers". But, like you said... Do what works for ya.

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lol, not sure why I CAPITLIZED those

Man, I was a real jackass last night, eh? I tend to be that way after a couple pints, not a good time to be trying to post advice. My apologies to you gentlemen if you took offense, though it appears Yankeehillbrewer took my asshattery in stride.

Truthfully, my experience tells me that pitching on a yeast cake works well. I have made some 40+ point beers using this practice, which motivates me to continue doing so. Usually going from a lower gravity wort to a higher gravity wort, especially if I want a nice clean profile, with minimal esters. Probably not a great idea with the more estery styles.

I have visited and toured many award winning breweries in the west, and many of them do essentialy pitch on the prior batch cake. I never got the impression that any of these brewers were "dumb".

Bob said:

First, yeast material in excess quickly leads to autolysis, which has flavor by-products which have very low flavor thresholds.

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This depends on the health of your yeast, and autolysis does not happen "quickly" which I am sure you know. Well, depending on what we mean by "quickly", I guess.

Bob, as a professional brewer, where are you brewing now? Do they distribute to the west coast? I'd like to keep an eye out for some and try it out if you can make a recommendation.

Again, my apologies for being an ass.

All's well that ends well

No worries, my friend. No offense taken, really. Being a sarcastic person by nature, I understand sarcasm when it's given!

At the moment, I'm consulting, not brewing regularly for any one house.

Bob

I was once scared and leary of reusing yeast, so I just decided to wash some out of a batch of hefe I had and reuse, it turned out great and brewed 4 hefe's with the same yeast (I always used it within 2 weeks and made starters to test viability). Get several mason jars, boil some water (cool it), fill jars with 3/4 with said water pour in some "yeast cake" cap and swirl. **** fall to the bottom good yeast stay in water, pour that into next clean jar, fill with water and place in fridge.

Im sure there is a more detailed post about this somewhere on HBT.

I never even thought of dumping fresh wort onto an old yeast cake until i started browsing HBT, there are so many other things in a yeast cake besides just yeast like bits of grains and hops, why not take the time to wash the yeast if you cant part with the three bucks it cost to buy fresh, im no professional by any means but it just seems like poor practice

This is a great thread. A lot of knowledge sharing here between six-0-turbo and Bob. Very nicely done guys, seriously. I've learned some things that I didn't know or even think about.

Thanks again!