Why Not to Pitch On Your Yeast Cake

[jwalker1140]

Apparently the word "trouble" bothers you. That's fine. Replace it with "extra time and effort." 90 minutes (by your estimate) to rinse, including an extra transfer, vs. 30 seconds to pour some slurry into a sanitized mason jar.

Now, I'm perfectly willing to put in extra time and effort if it offers a reasonable benefit. I assume you think rinsing does because, I'll paraphrase, "it lets the trub fall into a corner so you can pour the CLEAN yeast out." I would strongly suggest reading the work Steven Deeds has done on this topic here: http://woodlandbrew.blogspot.com/2012/12/yeast-washing-exposed.html

Among his more interesting findings is that the ratio of trub to viable yeast is the same throughout the rinsing container. Meaning, we're not really separating clean yeast from the trub by rinsing, we're just tossing most of it out. And that nasty trub we're so worried about, it's mostly protein that's actually beneficial to yeast as it aids in cell wall development, according to Fix. I was also surprised to learn that the top portion we try to collect contains a much higher level of bacteriological content, up to 100x more than in the bottom portion. So much for being cleaner....

Lastly, my takeaway from the OP was not that we all should do yeast counts or math, but rather the exact opposite since other more knowledgeable people (e.g., Fix, Daniels, Bamforth et al.) have already done that for us. Because of them, we can skate by with the simple rule-of-thumb that 1 cup of fresh slurry is enough for 5 gallons of 1.048 wort.

My reply probably sounds more snide or confrontational than I intend, and for that I apologize. I'm sure my tone would come across better if we were discussing over a couple pints. Heck, I'd even buy the next round.

 

[fosaisu]

I would strongly suggest reading the work Steven Deeds has done on this topic here: http://woodlandbrew.blogspot.com/2012/12/yeast-washing-exposed.html

Among his more interesting findings is that the ratio of trub to viable yeast is the same throughout the rinsing container. Meaning, we're not really separating clean yeast from the trub by rinsing, we're just tossing most of it out. And that nasty trub we're so worried about, it's mostly protein that's actually beneficial to yeast as it aids in cell wall development, according to Fix. I was also surprised to learn that the top portion we try to collect contains a much higher level of bacteriological content, up to 100x more than in the bottom portion. So much for being cleaner....

Lastly, my takeaway from the OP was not that we all should do yeast counts or math, but rather the exact opposite since other more knowledgeable people (e.g., Fix, Daniels, Bamforth et al.) have already done that for us. Because of them, we can skate by with the simple rule-of-thumb that 1 cup of fresh slurry is enough for 5 gallons of 1.048 wort.

Thanks for posting that very interesting link on yeast rinsing! Definitely worth a read for anyone that hasn't checked it out.

And I agree with your take on the OP's point -- he's saying that the research suggests you'll get better tasting beer using a cup of slurry (or two for a higher OG beer) instead of the whole yeast cake. No way to tell how many yeast cells are in a given cup of slurry without using a microscope, but it should at least be in or near the ball park of proper pitching rate, and much closer than an entire yeast cake which is virtually certain to contain way too many cells.

 

[cheezydemon3]

Not sure why, but I have done a complete reversal.

I get new yeast every time now.....I need to brew more often....

 

[Fordzilla]

Not sure why, but I have done a complete reversal.

I get new yeast every time now.....I need to brew more often....

Same thing happened to me. I stopped brewing as much and stopped reusing yeast.

 

[cheezydemon3]

Humph! Time to get back in!

 

[Fordzilla]

Especially since my 5 tap keezer is up and running. Gotta keep it stocked!

 

[grndslm]

Apparently the word "trouble" bothers you. That's fine. Replace it with "extra time and effort." 90 minutes (by your estimate) to rinse, including an extra transfer, vs. 30 seconds to pour some slurry into a sanitized mason jar.

Now, I'm perfectly willing to put in extra time and effort if it offers a reasonable benefit. I assume you think rinsing does because, I'll paraphrase, "it lets the trub fall into a corner so you can pour the CLEAN yeast out." I would strongly suggest reading the work Steven Deeds has done on this topic here: http://woodlandbrew.blogspot.com/2012/12/yeast-washing-exposed.html

Among his more interesting findings is that the ratio of trub to viable yeast is the same throughout the rinsing container. Meaning, we're not really separating clean yeast from the trub by rinsing, we're just tossing most of it out. And that nasty trub we're so worried about, it's mostly protein that's actually beneficial to yeast as it aids in cell wall development, according to Fix. I was also surprised to learn that the top portion we try to collect contains a much higher level of bacteriological content, up to 100x more than in the bottom portion. So much for being cleaner....

Lastly, my takeaway from the OP was not that we all should do yeast counts or math, but rather the exact opposite since other more knowledgeable people (e.g., Fix, Daniels, Bamforth et al.) have already done that for us. Because of them, we can skate by with the simple rule-of-thumb that 1 cup of fresh slurry is enough for 5 gallons of 1.048 wort.

My reply probably sounds more snide or confrontational than I intend, and for that I apologize. I'm sure my tone would come across better if we were discussing over a couple pints. Heck, I'd even buy the next round.

Let me just first say that that's an awesome post. But let me add my corrections first....

(1) There is 90 minutes of waiting. But maybe 180 seconds of actual work versus your claimed 30 seconds of actual work, which... if you're doing it properly... will still be sterilizing the jars by boiling them for 5 minutes, which means you're still going to be doing that full 180 seconds of actual work that yeast rinsing requires. The ONLY real time spent waiting is for the boiled water to cool && for the trub to fall to the bottom of the carboy. So we're talking 87 minutes of waiting is really what you're complaining about. There is NO EXTRA EFFORT, other than putting the boiled water & jars into the freezer. That is the ONLY bit of extra effort, as compared to the "save ALL the yeast cake" method. If that's what you consider to be trouble, then I can tell I wouldn't put you at the top of list of homebrewers that I'd be interested in tasting their beer (I don't have any list, but you get the idea. ).

(2) I will look at your link about yeast rinsing not completly removing the trub, but at the same time... I know that the author is not rinsing yeast properly if he is still getting trub in his first jar. By angling the carboy/fermenter so that the trub falls into a corner, waiting 30 minutes for the trub to fall to that corner, and using an auto-siphon... there will be ABSOLUTELY ZERO trub in your jars. That is yeast rinsing. I already know that whatever he did is the wrong way.

(3) The bit about throwing out the "nasty trub" actually being beneficial for the yeast is something that I hadn't really thought about... but when I think of "nasty trub" it is primarily hops that are not included in my next recipe. For example, my buddy and I got some yeast from an IPA from a local brewery. We only wanted to make a pale ale. What I consider a half-ass rinsing is to remove the trub from the completely new recipe, yet leave the "dirty water" in without pouring it off. A full rinsing would require *all* the yeast to drop (which takes a week or so) and leave clear liquid above. That would remove virtually every last possible ounce of old recipe from the new. But simply removing the hops is a bit better than not removing it at all, IMHO. Sure, the old, "nasty trub" is beneficial for the new recipe... but the new, "clean trub" is really what I'm after in my new recipe, and it's JUST as beneficial.

(4) I disagree that the OP thinks that yeast counting isn't important, as that's precisely what he's doing.... but he's doing it from a standpoint of a "rule-of-thumb" that's based on some generic recipe, which who knows what that is. The amount of hops changes with each recipe. The initial yeast count changes with each recipe. The various yeasts change their own final count with each recipe. It is virtually impossible for the homebrewer to do a yeast count, but it's far more accurate to spend the extra 5 seconds of work to put the boiled water into the freezer and the extra 87 minutes of waiting for the water to cool and the trub to fall in the carboy/fermenter.



But anyway.... I enjoyed your post and will read your link fully now. Just think that it is ZERO extra trouble to rinse the old trub, other than waiting. But "patience is a virtue" is an understatement when it comes to making good beer. And if yeast count is as important as the OP claims, an extra 87 minutes of waiting sure ain't gonna hurt and can only bring about the best consistency that any typical homebrewer is going to realize.

 

[grndslm]

OK.... so that is an interesting link, for sure, because the guy is actually using a microscope, apparently???

He is still not rinsing yeast properly, from what I can tell. To learn how to rinse properly, see the link I shared earlier, which is also in my signature. Pay particular attention to wolverinebrewer's posts, which I will link directly here ---> image && process to get that "100% yeast".

Steven Deeds, whose blog you linked to earlier, is again definitely not doing it right, as you can see from that pic on the top of the article. Something else that troubles me is that he mentions there being bacteria in the liquid. Where is that bacteria coming from?? Surely not his boiled water, right? That was bacteria that was already in the yeast cake. He's saying that it's a GOOD IDEA to remove that bacteria by pitching the liquid. Sure, but in my "half-ass rinsing" method I'm mentioning, there is no legitimate opportunity to dump the liquid within less than 3 days, otherwise you're dumping the least flocculant yeast, which you may want to keep around for as many generations as possible (even just the next one). Now that I'm thinkin about it, tho, in order to see a decent guesstimate on how much yeast you have with my half-ass method, you will need several hours, and preferably overnight to get a vague idea of how much yeast you have. But if done properly, you can at minimum, remove ALL the trub from the equation.

The last set of questions, initiated by CA Brewer in Jan. 2013, presents some information that I would think needs more elaboration. The very last sentence, in particular, "In my experience there is more protein from the wort than added when by the repitched slurry." is a sentence that I don't find incredibly legible. Is he agreeing with me that the new, "clean trub" provides the protein that we're really after, as opposed to the old, used, "nasty trub"? I think he is, no?

He has a newer post ( http://woodlandbrew.blogspot.com/2013/01/yeast-washing-revisited.html ) that I have yet to read, as well... but, again, from the picture... he's still not rinsing properly, because he's still seeing trub.

I read Yeast a year or so ago, but I don't remember exactly how you measure "viability". Perhaps someone can refresh my memory on how this is done??

 

[EarlyAmateurZymurgist]

Yeast washing is a completely unnecessary step that is more harmful than it is beneficial. Beer is a significantly more hostile environment to house microflora than boiled water. Boiling does not kill spores (water has to be autoclaved to kill spores), and most water supplies have a pH that is significantly higher than beer, which will allow the spores to germinate. The proper way to separate yeast from the trub is to leave enough fermented beer behind after racking to be able to swirl the viable yeast back into suspension. Dead yeast cells and the heaviest fractions will quickly settle out, leaving mostly healthy yeast in suspension. It is beneficial to the health of the culture bring a small amount of the protein fraction of the trub over with the yeast.

Commercial breweries only wash their yeast when they are performing an acid wash in an attempt to salvage a crop that is infected with house microflora. The pH of the solution that is used during acid washing is significantly lower than that of tap water.

 

[Denny]

Yeast washing is a completely unnecessary step that is more harmful than it is beneficial. Beer is a significantly more hostile environment to house microflora than boiled water. Boiling does not kill spores (water has to be autoclaved to kill spores), and most water supplies have a pH that is significantly higher than beer, which will allow the spores to germinate. The proper way to separate yeast from the trub is to leave enough fermented beer behind after racking to be able to swirl the viable yeast back into suspension. Dead yeast cells and the heaviest fractions will quickly settle out, leaving mostly healthy yeast in suspension. It is beneficial to the health of the culture bring a small amount of the protein fraction of trub over with the yeast.

Commercial breweries only wash their yeast when they are performing an acid wash in an attempt to salvage a crop that is infected with house microflora. The pH of the solution that is used during acid washing is significantly lower than that of tap water.

ALL OF THIS!!!!^^^^^

You can quote numbers and studies to me all day, but all I care about is the quality of my beer and the ease and fun of making it. I've rinsed yeast and I've saved and reused it without rinsing it. I saw no difference in performance or final beer quality. It took extra time and effort to do the rinsing, and I don't care to expend time and effort without a noticeably beneficial return. Yeast rinsing didn't give me that noticeably beneficial return and I quit doing it. My own experience is all the evidence I need.

 

[jwalker1140]

Grndslm, you'll have to forgive me for not taking the "time and effort" to offer a full point-by-point reply, but I would like to make a few comments.

I will agree that waiting 87 minutes may not be a big deal ... unless you want to go to bed, go to work, go to a movie, go out to dinner, etc....

I hit my mason jars with a few squirts of StarSan from a spray bottle. Quick and easy. You imply this isn't good enough when you write that boiling the bottles in water for 5 minutes is the proper method because it sterilizes them. We'll have to agree to disagree on this point. At the very least, you may want to research the difference between 'sterilizing' and 'sanitizing' before you make more posts on this topic.

You also seem convinced that Bernie Brewer's 'yeast washing illustrated' approach is the proper way to rinse yeast and that other methods, like the one Steven Deeds used, are wrong. Since you indicate that you've read "Yeast" by White and Zainasheff, you've realized they also do it wrong. How embarrassing. If you let them know, maybe they'll fix this in the 2nd edition.

I've used the 'yeast washing illustrated' technique many times. I've also used the OP's 'why not to pitch...' technique many times. I'm not here to evangelize for one technique over another, but I will say that, overall, I've experienced better results when I've used the OP's technique. YMMV.

 

[bob1852]

I'll probably start saving yeast in those 4oz canning jars. Why waste all that headspace with beer, or worse, water. Right?

 

[grndslm]

Yeast washing is a completely unnecessary step that is more harmful than it is beneficial. Beer is a significantly more hostile environment to house microflora than boiled water. Boiling does not kill spores (water has to be autoclaved to kill spores), and most water supplies have a pH that is significantly higher than beer, which will allow the spores to germinate. The proper way to separate yeast from the trub is to leave enough fermented beer behind after racking to be able to swirl the viable yeast back into suspension. Dead yeast cells and the heaviest fractions will quickly settle out, leaving mostly healthy yeast in suspension. It is beneficial to the health of the culture bring a small amount of the protein fraction of the trub over with the yeast.

Commercial breweries only wash their yeast when they are performing an acid wash in an attempt to salvage a crop that is infected with house microflora. The pH of the solution that is used during acid washing is significantly lower than that of tap water.

Good post!

The only difference between what a brewery does and what I do is that they use the SAME yeast for the SAME recipe. If I'm using the SAME yeast for a DIFFERENT recipe, rinsing definitely has its own benefits.

Grndslm, you'll have to forgive me for not taking the "time and effort" to offer a full point-by-point reply, but I would like to make a few comments.

Forgiven.

I will agree that waiting 87 minutes may not be a big deal ... unless you want to go to bed, go to work, go to a movie, go out to dinner, etc....

You can certainly do all those things while waiting. That's the entire point that it isn't any extra "effort", other than the few seconds it takes to toss the jars and water into the freezer/fridge. Time, yes.. but time is something that a brewer should have plenty of. So the point is moot.... but to each his own. This is NOT the reason for either of us choosing or not choosing to rinse or save/pitch a yeast cake, however... so perhaps we won't dwell on this much longer.

I hit my mason jars with a few squirts of StarSan from a spray bottle. Quick and easy. You imply this isn't good enough when you write that boiling the bottles in water for 5 minutes is the proper method because it sterilizes them. We'll have to agree to disagree on this point. At the very least, you may want to research the difference between 'sterilizing' and 'sanitizing' before you make more posts on this topic.

I have searched the difference between the two, before, but perhaps not researched the topic. From my understanding, sanitizing (star san, idiophor) removes 99.99% of microorganisms, whereas sterilizing (boiling, autoclaving) removes 100% of living microorganisms. Apparently autoclaving removes spores, but boiling still goes a step further than sanitation. Perhaps I am missing something else??

You also seem convinced that Bernie Brewer's 'yeast washing illustrated' approach is the proper way to rinse yeast and that other methods, like the one Steven Deeds used, are wrong. Since you indicate that you've read "Yeast" by White and Zainasheff, you've realized they also do it wrong. How embarrassing. If you let them know, maybe they'll fix this in the 2nd edition.

I actually don't quote Bernie Brewer's approach at all. And I did quote to you wolverinebrewer's approach as the proper way to rinse yeast. Perhaps you should check again. I'll just quote my earlier post....

To learn how to rinse properly, see the link I shared earlier, which is also in my signature [HINT: This is not Bernie Brewer's post]. Pay particular attention to wolverinebrewer's posts, which I will link directly here ---> image && process to get that "100% yeast".

I've used the 'yeast washing illustrated' technique many times. I've also used the OP's 'why not to pitch...' technique many times. I'm not here to evangelize for one technique over another, but I will say that, overall, I've experienced better results when I've used the OP's technique. YMMV.

And yes, I'm not here to evangalize any method, but I am here to learn. I'm not sure how much fungus spores or whatever are actually going to survive a boil, and how many microorganisms, flora are "introduced" from boiled water.... but I'd certainly like to learn more on the topic. As of right now, I stick with this OP's suggestion that yeast count is important... however, I propose that rinsing properly will separate ALL trub away from the yeast and will yield the most accurate estimate of yeast count for home brewers. Removing the trub is also beneficial when not repeating the same recipe, as every real brewery does. To each their own, for sure... but I'm definitely not beyond learning.

 

[jwalker1140]

Time, yes.. but time is something that a brewer should have plenty of. So the point is moot.... but to each his own. This is NOT the reason for either of us choosing or not choosing to rinse or save/pitch a yeast cake, however... so perhaps we won't dwell on this much longer.

Actually, this is the reason, along with the fact that I've experienced better results following the OPs approach. I'm not sure why you're so determined to argue something that's a matter of personal perception. Personally, I don't have all of this free time you seem to think brewers should have. And even if I did, I wouldn't be willing to waste any of it doing something that hasn't made my beers better.

At this point I'm starting to repeat myself, which is my clue that I need to move on. Happy brewing.

 

[EarlyAmateurZymurgist]

Good post!

The only difference between what a brewery does and what I do is that they use the SAME yeast for the SAME recipe. If I'm using the SAME yeast for a DIFFERENT recipe, rinsing definitely has its own benefits.

There is still no advantage to washing yeast with boiled water. In fact, washing yeast with water is detrimental to the health of the culture, as it raises the pH of the solution and removes all of the nutrients. If one is brewing a different recipe, all one needs to do and should do is to decant the liquid fraction of the crop and replace it with new wort before swirling the solids back into suspension.

 

[EarlyAmateurZymurgist]

Since you indicate that you've read "Yeast" by White and Zainasheff, you've realized they also do it wrong. How embarrassing. If you let them know, maybe they'll fix this in the 2nd edition.

Please elaborate on how White and Zainasheff are "doing it wrong" in their book? I need to go get a bowl of popcorn because this thread is about to get entertaining.

 

[jwalker1140]

Please elaborate on how White and Zainasheff are "doing it wrong" in their book? I need to go get a bowl of popcorn because this thread is about to get entertaining.

I wasn't suggesting that I think they are. I was inferring that since Grndslm has argued that the technique he happens to prefer is "proper" and that people who do it differently are doing it wrong, that he must also think White and Zainasheff are doing it wrong since they also do it differently. Believe me, I'm nobody to challenge White and Zainasheff on this topic.

 

[grndslm]

Like I said, it's been over a year since I've read the book. If they are getting trub, however, like the guy's blog you linked to... they are doing it wrong.

One more time... if you're getting trub in your rinsed yeast, you are doing it wrong.

To learn how to rinse properly, see the link I shared earlier, which is also in my signature [HINT: This is not Bernie Brewer's post]. Pay particular attention to wolverinebrewer's posts, which I will link directly here ---> image && process to get that "100% yeast".

I've only rinsed yeast a few times, but I never get any trub if I'm using an autosiphon. Regardless of if I use an autosiphon or I pour, the yeast always manages to do its job. So, hey, maybe neither of us is doing it wrong. But I can say, undoubtedly, the guy in the blog that you linked to is doing it wrong.

 

[grndslm]

If one is brewing a different recipe, all one needs to do and should do is to decant the liquid fraction of the crop and replace it with new wort before swirling the solids back into suspension.

And in order to do that, you'd need to wait anywhere from 3 to 7 days, in order for that least flocculant yeast to drop.... otherwise you aren't going to preserve the "integrity" of the yeast.

But everybody knows that people who save/pitch yeast cakes don't have any time to wait....

 

[EarlyAmateurZymurgist]

And in order to do that, you'd need to wait anywhere from 3 to 7 days, in order for that least flocculant yeast to drop.... otherwise you aren't going to preserve the "integrity" of the yeast.

But everybody knows that people who save/pitch yeast cakes don't have any time to wait....

Preferably, one doesn't want to carry the least flocculent yeast over to the next fermentation. In a pure culture, the least flocculent yeast cells tend to be respiratory-deficient mutants.

The photo shown below contains a plate that I streaked from a yeast culture that was harvested from a bottle of bottle-conditioned beer. The small colonies are more than likely respiratory-deficient mutants (a.k.a. petite mutants or simply "petites"). The colonies in the rectangle are the reference culture.

 

[grndslm]

Preferably, one doesn't want to carry the least flocculent yeast over to the next fermentation. In a pure culture, the least flocculent yeast cells tend to be respiratory-deficient mutants.

Interesting. That's definitely a new one to me.

I don't suppose you have any material on the subject matter for me to review, do you?

 

[EarlyAmateurZymurgist]

Interesting. That's definitely a new one to me.

I don't suppose you have any material on the subject matter for me to review, do you?

It's common knowledge that the least flocculent fraction of a pure culture is composed mostly respiratory-deficient mutants. That's why crops are taken from the middle of the yeast layer in the cone of a conical fermentor.

A Wiki entry on petite mutation (I know, Wiki is not a citable source):

http://en.wikipedia.org/wiki/Petite_mutation

A seminal paper on respiratory-deficient mutants is:

Respiratory Deficiency in Brewing Yeast Strains-Effects on Fermentation, Flocculation, and Beer Flavor Components. José R. Ernandes, John W. Williams, Inge Russell, and Graham G. Stewart

 

[grndslm]

WRONG POST.

Please delete.

 

[Bob]

(4) I disagree that the OP thinks that yeast counting isn't important, as that's precisely what he's doing.... but he's doing it from a standpoint of a "rule-of-thumb" that's based on some generic recipe, which who knows what that is. The amount of hops changes with each recipe. The initial yeast count changes with each recipe. The various yeasts change their own final count with each recipe.

Kind of. I'm the OP. I've been away for a while, but I'm baaaaaack! :fro:

For the home brewer, cell counts are impractical. But hey, if you're anal enough to do it, knock yourself out!

The "generic recipe" is based on an OG of 12 degrees Plato, or 1.048 specific gravity. That's all that's really important. IBU, except in the case of ridiculous Imperial whatsits, are immaterial to pitch rate. Yes, the count changes with each recipe. That's why I very clearly wrote the formulae in the original post. Let me state them again:

The standard, according to Fix, Daniels, Bamforth et al., is one million active cells per milliliter of wort per degree Plato. Or:

1,000,000*1ml*1°P

Constants:

• There are 3785 ml per US gallon, or 18,925 ml in 5 US gallons. Round this up to 19,000 (19L) for ease of calculation if you do predominantly 5 gallon batches.
• One °P is roughly equivalent to 4 points of gravity. For an approximation, 1.048 is thus 12°P. This goes askew above around 1.060; in fact, you may find it simpler to consult a chart like this: http://plato.montanahomebrewers.org/ - or use the formula:

{Plato/(258.6-([Plato/258.2]*227.1)}+1 = Specific gravity

Thus, for 5 gallons of wort at 12°P, we need

1,000,000 * 1 ml * 12°P, or 12,000,000 cells per ml.

12,000,000 * 19,000 = 228,000,000,000 - that's 228 billion cells.

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.

Thus, 228 ml of freshly-harvested slurry is the correct pitch for 5 gallons of 1.048 wort. Conveniently, that's only a few ml less than that found in one cup (8 fluid ounces).

Jamil Zainasheff recommends a modified pitch rate, advocating 0.75 million cells per ml per °P for ale ferments and 1.5 million 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.

You can very easily scale the rate up or down depending on gravity.

I also agree without reservation that washing is unnecessary and potentially damaging unless you're engaged in laboratory-grade acid washing in order to isolate strains.

There is still no advantage to washing yeast with boiled water. In fact, washing yeast with water is detrimental to the health of the culture, as it raises the pH of the solution and removes all of the nutrients. If one is brewing a different recipe, all one needs to do and should do is to decant the liquid fraction of the crop and replace it with new wort before swirling the solids back into suspension.

THIS. Goes back to what I posted ages ago about the best place to store yeast is ...

...wait for it...

...under beer.

 

[grndslm]

There are most definitely benefits to rinsing/washing yeast....

https://www.homebrewtalk.com/f163/saving-yeast-432059/index3.html#post5530951

 

[Bob]

Yes, but those benefits are outweighed by the negatives. At least for me. You get down with your bad self - if washing works for you, have fun. For me, it doesn't, and the science hasn't sufficiently supported the conclusions provided by its proponents.

This is another of those double standards imposed by brewers who think they're doing something cool. They insist there's no chance of introducing contamination in their yeast-washing, but 99% of the time, they're the same people who tell new brewers not to rack because of the chance of contamination. The same principle holds, so there's nothing but cognitive dissonance in holding two opposing views. You might say, "Ah, but I'm an experienced brewer, so I can be more assured of proper sanitation." To which I reply, "Bollocks." Any fool can follow simple instructions and properly sanitize.

The trouble is even if proper sanitation procedures are followed, you're still needlessly introducing opportunities for bad stuff to happen. That's just stupid. The fact is that simply repitching unwashed slurry in appropriate amounts will produce excellent, nay, outstanding beer.

Here's the long and short of it: If the extra step doesn't really do anything, there Is. No. Point. in performing it. Washing yeast has no discernible effect on the product. Ergo, there is no point in performing the act.

Cheers,

Bob

 

[Bob]

It also has a lot to do with homebrewers thinking they're doing something worthwhile, but they're not. Here are a couple of simple facts:

1. Hundreds of years of dealing with yeast have taught us that the best place to temporarily store yeast intended for repitching is under beer. Not boiled water - beer. Not any other substance - beer.

2. As others have pointed out, what homebrewers call "yeast washing" is really "yeast rinsing". It's another technique the homebrew community has taken from professional brewers in a half-assed way because they don't fully understand it (like hot-side aeration, ad nauseum). Then - worse! - they over-think the activity, and back-document into all manner of pre-determined justifications and call it "science".

3. Then things take on the proportions of religion. "ALWAYS wash your yeast!" "Just pitch right on to your yeast cake!" "NEVER rack your beer!" "If you splash about in your beer you'll ruin it!" They're all kind of good ideas. There's a kernel of truth at the core of each. Unfortunately, the reasoning behind them is frightful if it exists at all, the mysticism surrounding the kernel of truth at the core is blown out of any semblance of proportion, adherents are more rabid the less they truly understand what they're talking about - you know, just like religion.

Anyway. I need to get back to work.

Bob

 

[mtnagel]

Bob, great info as always. I rinsed yeast for a few months, but have since gone the way of harvesting yeast from my starters. It just takes some more pre-planning, but I always just make about 100 billion more yeast cells than needed for my beer and save that. It has worked great for me so far.

But I do have to ask if I wanted to save some yeast from primary after fermentation, you're saying that I can just take some of the trub at the bottom of the bucket and store that in a sanitized jar for later use, right? No further steps necessary? If so, how long can you save that for?

 

[rustym]

Great topic and information! We get the best for sure!

Since were on this topic, this may or may not be the appropriate time to bring this up but it looks like we have some heavyweights here and this question has been bugging me.

I have always used Jamils calculations to pitch the correct amount of yeast. Then recently, yeastcalc.com added Kai's stirplate options for calculating pitch rates. Kai's contention seems to be that Jamils rates would always have you OVER pitching. It's frustrating to see in one calculater that I could be overpitching or underpitching with the same volume of starter depending on which method you use.

 

[Biobrewer]

Great topic and information! We get the best for sure!

Since were on this topic, this may or may not be the appropriate time to bring this up but it looks like we have some heavyweights here and this question has been bugging me.

I have always used Jamils calculations to pitch the correct amount of yeast. Then recently, yeastcalc.com added Kai's stirplate options for calculating pitch rates. Kai's contention seems to be that Jamils rates would always have you OVER pitching. It's frustrating to see in one calculater that I could be overpitching or underpitching with the same volume of starter depending on which method you use.

Personally, I use Kai's method, because he actually provides a scientific basis for it, where, as he even points out in his write-up, "Jamil never published how he arrived at the model used in his calculator. As a result I have to draw conclusions based on what I can observe when I run data points through his calculator."

 

[Biobrewer]

Preferably, one doesn't want to carry the least flocculent yeast over to the next fermentation. In a pure culture, the least flocculent yeast cells tend to be respiratory-deficient mutants.

I would largely agree with this. You wouldn't want to harvest yeast as it is stratified into a highly flocculant and less flocculant layer.

The photo shown below contains a plate that I streaked from a yeast culture that was harvested from a bottle of bottle-conditioned beer. The small colonies are more than likely respiratory-deficient mutants (a.k.a. petite mutants or simply "petites"). The colonies in the rectangle are the reference culture.

I do quite a bit of plating myself, and I'm not sure you can say all of the small colonies are more then likely petite mutants. There may be some in there, but just as I see on this plate, when I plate a higher cell density like you have on the left side of the plate as opposed to a lower cell density like you have on the right side of the plate, the colonies on the higher density side tend to be smaller and the colonies on the lower density side tend to be larger. I think that this has more to do with space and availability to nutrients and a carbon source.

Also, by "reference culture", are you saying you streaked 3 cells of another culture on that plate, or are you calling them "reference" because they are larger?

 

[brewski09]

If you make good beer using Jamil's calculations, why worry about it?

 

[Biobrewer]

If you make good beer using Jamil's calculations, why worry about it?

It probably isn't worth worrying about. I simply like the Kai method because there is an actual scientific rationale to it. I'm sure Jamil has one too, I'm just not sure what it is.

Cheers!

 

[rustym]

If you make good beer using Jamil's calculations, why worry about it?

For myself, I don't want to make good beer, I want to make great beer. I can through some extract, hops and yeast together and make good beer but when you know why and how things work, I think even on a basic homebrewer level, we can make great beer.

The fact that we can have this kind of discussion (especially how this thread started) is what helps us all learn how to make the best beer we can.

 

[Bob]

But I do have to ask if I wanted to save some yeast from primary after fermentation, you're saying that I can just take some of the trub at the bottom of the bucket and store that in a sanitized jar for later use, right? No further steps necessary? If so, how long can you save that for?

All those questions are answered up-thread if not in my OP. Thanks for the kind words!

Bob

 

[Bob]

Speaking to the sources of Jamil's method, he at least used to list all his sources at MrMalty. IIRC they include such luminaries as Fix, Davis, et al. Plus there's the ol' brewery rule of thumb which I describe in my OP which coincides with Jamil's rate and has been proved to make outstanding beer in hundreds if not thousands of breweries for generations.

Fermentation science is fascinating!

 

[Biobrewer]

Fermentation science is fascinating!

For me, the science is why I use Kai's method, because it's clearly stated and he shows a scientific basis for the underlying assumptions behind the calculation. I have used Mr. Malty though in the past though, and it did work well. I don't think anyone has stated in this tread that it won't work or won't produce good/great beer.

I think it's just a matter of personal preference.

 

[grndslm]

Bob, you should try reading the last few posts of that thread I linked you to . You'll see that there most certainly is science to back up the conclusions of the beneficial purposes of yeast washing.

EAZ says there's NO BENEFIT in the face of scientific evidence. Then you say there are benefits, but the negatives outweigh them for you. Then you reverse stance and say there is NO POINT. Whose stance is really the one of a religious faith? I am acknowledging the pros and cons of these two methods, and there is scientific evidence to back up my reasoning. Where is YOUR scientific evidence?

 

[grndslm]

I do quite a bit of plating myself, and I'm not sure you can say all of the small colonies are more then likely petite mutants. There may be some in there, but just as I see on this plate, when I plate a higher cell density like you have on the left side of the plate as opposed to a lower cell density like you have on the right side of the plate, the colonies on the higher density side tend to be smaller and the colonies on the lower density side tend to be larger. I think that this has more to do with space and availability to nutrients and a carbon source.

I was curious about this myself.

Is there any evidence for this claim other than a belief?

 

[Denny]

Bob, you should try reading the last few posts of that thread I linked you to . You'll see that there most certainly is science to back up the conclusions of the beneficial purposes of yeast washing.

EAZ says there's NO BENEFIT in the face of scientific evidence. Then you say there are benefits, but the negatives outweigh them for you. Then you reverse stance and say there is NO POINT. Whose stance is really the one of a religious faith? I am acknowledging the pros and cons of these two methods, and there is scientific evidence to back up my reasoning. Where is YOUR scientific evidence?

Science is great, but it's what's in the glass that really matters. My own experience guides me.