[archstanton]

Marshall's experiments are always well thought out and performed.  In this case, I think we have a single data point rather than an overall conclusion.

I willing to bet that Marshall's findings hold over a much larger data set.  There are many forgiving yeast strains that behave well into the low seventies.  I imported six British strains last year that were anything but forgiving, and most would behave up into the high sixties.  Several of the strains were POF+, which led to increased phenol production as the internal temperature approached 70F.  However, to be fair, these strains had been conditioned to ferment ordinary bitter; hence, they were stressed on more than one front.

Agreed, although I think the caution to avoid applying these results universally is a valid one. In my own experience his results certainly match my experience with many ale strains.

I do think you have a valid point about POF+ strains. Hefe and some Belgian strains are much more temperature sensitive in my experience.

I would most like to see this retested for lager yeasts that are known to be forgiving about temperature (such as WY2124) to see how far they can be pushed.

I don't see where anyone, especially in the article, suggests you apply the finding universally. What is ironic is that the article is dispelling a universally applied concept.

hardly dispels anything. He pitched cool and let the temp ramp. it wasn't particluarly high until 40 hours after pitch.

I will continue to suggest to new brewers who want to improve their product that the chill the wort well before pitching and pitch at or below desired ferm temp. I might even point to this article to support that idea given that he shows how the activity of the yeast will raise the temp of the wort.

Given that ester formation is largely accomplished in the lag and log phases and both of those were pretty well over before the warm' batch exceeded 62f I would say that what this xbmt shows is that chilling to a desirable pitch temp can make up for lack of careful temperature control later in the fermentation.

a more representative experiment would, I think, involve pitching the 'warm' batch at 72 and letting it rise free from there vs chilling to 56 and letting it free rise.

Certainly I don't agree with your opening statement.  And whatever you do don't read his pitch temp experiment, I don't think you are ready.

[dmtaylor]

I'd written a long ranty response, but deleted it.  Suffice it to say that nothing is dispelled, supported or refuted.  One data point is hardly worth any more words out of me.

[morticaixavier]

[...]
Certainly I don't agree with your opening statement.  And whatever you do don't read his pitch temp experiment, I don't think you are ready.

I'm not exactly sure what you are saying here? Has he performed a pitching temp experiment? I was not aware. I'm fairly certain that I could in fact read it and manage to keep my head but who's to say till it happens?

did you wish to in some way refute my interpretation of this article? or just offer aimless snark?

**EDIT**
I think maybe I was a bit snarky there myself. I apologize. There has been a fair amount of discussion of ferm temp advice to keep it cool being overblown lately. I know that when I advise people to pay attention to fermentation temp I try to be clear that pitching temp and early hours temp are the most important periods. Given that many of the new brewers who complain that their beer isn't all it could be are telling tales of pitching at a high temp and fermenting at a high temp. No one is chilling beer down to 56 and then failing to control fermentation temperatures. At least not intentionally.

[morticaixavier]

so I read the pitching temp experiment. he pitches warm but immediately reduces to a solid ferm temp. So once again, the spirit of the advice is missing. We tell new brewers with no temp control to chill as far as they can before pitching because they will not be able to control the temp rise after.

to quote: "Another situation where I think it remains beneficial to pitch cool is for those brewers who don’t have precise control over their fermentation temp, as pitching warm without the ability to chill the beer relatively quickly will almost certainly result in a beer actively fermented outside of the appropriate temp range"

[dmtaylor]

Maybe I should start a blog so everybody picks apart my experiments.......................................






Nah, no thanks. 

[morticaixavier]

Maybe I should start a blog so everybody picks apart my experiments.......................................






Nah, no thanks. 

I'm with you there.

[archstanton]

[...]
Certainly I don't agree with your opening statement.  And whatever you do don't read his pitch temp experiment, I don't think you are ready.

I'm not exactly sure what you are saying here? Has he performed a pitching temp experiment? I was not aware. I'm fairly certain that I could in fact read it and manage to keep my head but who's to say till it happens?

did you wish to in some way refute my interpretation of this article? or just offer aimless snark?

**EDIT**
I think maybe I was a bit snarky there myself. I apologize. There has been a fair amount of discussion of ferm temp advice to keep it cool being overblown lately. I know that when I advise people to pay attention to fermentation temp I try to be clear that pitching temp and early hours temp are the most important periods. Given that many of the new brewers who complain that their beer isn't all it could be are telling tales of pitching at a high temp and fermenting at a high temp. No one is chilling beer down to 56 and then failing to control fermentation temperatures. At least not intentionally.

I was just going to reply - snarky :-). But alas your edit, I was not trying to be short, I had to go.  I did agree with most of what you said that is why I singled out the one item. I had already studied the ferm process on it and thought of many of the same things as being possible. However it was already at 68 degrees in only 24 hours, so I'm less reluctant to go with it having possibly missed the typical ester formation period. The standard advice is to hold temperature for 2-3 days, especially while it climbs above ambient.  Where are the fusels since it pushed 72 by 36 hours?  What he did is by no means what I would consider a best practice, but I have had no choice but to do it before. Consistency will surely be difficult.  Different yeast will behave differently.   

[archstanton]

so I read the pitching temp experiment. he pitches warm but immediately reduces to a solid ferm temp. So once again, the spirit of the advice is missing. We tell new brewers with no temp control to chill as far as they can before pitching because they will not be able to control the temp rise after.

to quote: "Another situation where I think it remains beneficial to pitch cool is for those brewers who don’t have precise control over their fermentation temp, as pitching warm without the ability to chill the beer relatively quickly will almost certainly result in a beer actively fermented outside of the appropriate temp range"

I have not read it for sometime.  IIRC he proposes the old pitch 2 degrees below fermentation temperature to get the best beer possible. Which he clearly does not do. The result was in direct contrast with your statement
"I will continue to suggest to new brewers who want to improve their product that the chill the wort well before pitching and pitch at or below desired ferm temp"
I am not even sure what chill your wort well means ;-) ( I 'm sure this was a typo of sorts)

Sure you can sit back and conjure up a situation where it won't work, but his point is it can work, against conventional wisdom.  I have no dog in this fight, I pitch a couple degrees cool and control my fermentation temps in a controlled chamber.  Consistency is what comes to mind first, before quality.  Great beers can be made lots of ways. 

[ynotbrusum]

Many ways to make great beer, for sure.  Interesting result for this yeast this time.  I wonder what the relative pitch rate was...

[S. cerevisiae]

a more representative experiment would, I think, involve pitching the 'warm' batch at 72 and letting it rise free from there vs chilling to 56 and letting it free rise.

I used to pitch at 70F to 72F and allow the batch to cool to 66F on a regular basis before I went on a 100% lager, 100% of the time kick.  Beers made using that strategy were easily as clean as the beers that I have tasted using the generally-accepted modern approach to home brew fermentation. 

As I mentioned in the RPM threat, the reason why most home brewers see a reduction in overall fermentation trash when starting ales in the high fifties/low sixties is that low-temperature ale fermentation favors domesticated microflora. Holding the fermentation low during the lag and early exponential phases gives the pitched culture a huge advantage over its competitors, especially household bacteria. The bacteria cell count in a fermentation increases eightfold every time the yeast cell count doubles because bacteria cells divide every thirty minutes whereas yeast cells divide every ninety minutes.  The yeast cells own the fermentation by the time that the batch warms up enough for wild microflora to become active.

[morticaixavier]

a more representative experiment would, I think, involve pitching the 'warm' batch at 72 and letting it rise free from there vs chilling to 56 and letting it free rise.

I used to pitch at 70F to 72F and allow the batch to cool to 66F on a regular basis before I went on a 100% lager, 100% of the time kick.  Beers made using that strategy were easily as clean as the beers that I have tasted using the generally-accepted modern approach to home brew fermentation. 

As I mentioned in the RPM threat, the reason why most home brewers see a reduction in overall fermentation trash when starting ales in the high fifties/low sixties is that low-temperature ale fermentation favors domesticated microflora. Holding the fermentation low during the lag and early exponential phases gives the pitched culture a huge advantage over its competitors, especially household bacteria. The bacteria cell count in a fermentation increases eightfold every time the yeast cell count doubles because bacteria cells divide every thirty minutes whereas yeast cells divide every ninety minutes.  The yeast cells own the fermentation by the time that the batch warms up enough for wild microflora to become active.

I can see your point but I think when it comes to begining homebrewers the problems I most often encounter are fusels. Sure those could be the fault of other microflora but given that most instructions have them pitching at 75 and 'keeping the carboy in a closet' that is caused by excessive fermentation temperature pure and simple.

On pitching warm and chilling the rest of the way quickly. The pitch temp experiment referenced above does seem to indicate that it's not as much of an issue as is generally thought.

My concern would be that if you take these two experiments together and you fail to apply a sense of nuance you get a) pitching warm is okay and b) fermenting uncontrolled is okay and we are back on terrible 1990's kit instructions again. Then I start getting pounding fusel headaches everytime I taste someones homebrew. I appreciate the value of isolating a variable and testing it but drawing conclusions from those results without taking into account the interplay between all the other variables is naive.

My take away from this experiment is that it's okay to let the temp rise from a nice low pitch temp. I already knew this and I believe it is, or is quickly becoming, 'common sense'.

My take away from the pitch temp experiment is that if you are concerned about the biological stability of your wort you can choose to pitch the yeast while the wort is still a bit too warm for a happy fermentation so long as you quickly get the temperatures down to within a desirable temp.

All of these things can be easily and more understandable summarized to the beginner who's mind you do not wish to cloud as: Pitch cool and control temps for best results.

[denny]

I'm in contact with Marshall fairly frequently as a fellow experimenter.  He's aware of the shortcomings of some of his experiments, but that doesn't reduce the validity of what he does.  FWIW, this experiment will be repeated with WY1214, which is one of the most temp sensitive yeasts I've ever run across.

[Wort-H.O.G.]

I'm in contact with Marshall fairly frequently as a fellow experimenter.  He's aware of the shortcomings of some of his experiments, but that doesn't reduce the validity of what he does.  FWIW, this experiment will be repeated with WY1214, which is one of the most temp sensitive yeasts I've ever run across.

that's a great idea. I'm a fan of his experiments, and its good he's open to critiquing.

[morticaixavier]

I'm in contact with Marshall fairly frequently as a fellow experimenter.  He's aware of the shortcomings of some of his experiments, but that doesn't reduce the validity of what he does.  FWIW, this experiment will be repeated with WY1214, which is one of the most temp sensitive yeasts I've ever run across.

I don't mean to knock Marshall. In fact having read a couple of the write ups I think me makes a good effort to use fairly narrow, nuanced language in his conclusions. I am more concerned with others drawing conclusions that are not warranted.

[denny]

I'm in contact with Marshall fairly frequently as a fellow experimenter.  He's aware of the shortcomings of some of his experiments, but that doesn't reduce the validity of what he does.  FWIW, this experiment will be repeated with WY1214, which is one of the most temp sensitive yeasts I've ever run across.

that's a great idea. I'm a fan of his experiments, and its good he's open to critiquing.

Marshall is a great guy and all he wants to do is come up with info he can share with other homebrewers.  He's more than open to ideas about how to do that.