Fermentation Experiment

Cool article, what are your thoughts?

I think he selected a yeast that is pretty clean at a very wide range of temperatures.  Other yeasts are not so inclined.  FWIW, I have followed his Narziss-style lager fermentation approach with great success.  As always, try things and select from them what works best for you!

My humble opinions… wrong yeast, wrong style.  The Kolsch yeast was going to turn out clean no matter what.  Try this with a different yeast and get completely different results.  Temperature effects are very strain dependent.

had same thoughts yesterday when I read his post. try and ferment a belgian, hefe, or english and test those results.

If he wanted to test true first brew fermentation temperatures he should have gone a little warmer than 72. I also agree that the kolsch yeast is fairly forgiving and doesn’t get too out of control with esters when fermented in the low 70s.

However, what I think helped drive cleaner fermentation is that he made a starter for the yeast and pitched a healthy volume. A new homebrewer likely is just pitching in a packet of dry yeast and letting it go. Underpitching at warmer temperatures is going to produce a more significant ester profile because you are stressing the yeast in two ways rather than just seeing the effects of one stress cause. IMO that is what makes his experiment less responsive to the situation he sets up with the new homebrewer. If he really wanted to demonstrate the significance of temperature control in those conditions he would have pitched directly out of a packet of dry yeast or a smackpack and then let the temperatures drift in the wrong directions.

I’m not sure that fermentation temperature control is always the first thing brought up to a new homebrewer. People also point out the underpitching as well as the fact that those boxed kits usually have questionably old ingredients and the recipes aren’t exactly world class in most cases. Add all of that together with a beer fermented too warm and you have a less than stellar beer.

Nailed it!!!  Matches up with my reality. Not familiar with that yeast, but wlp-001 and wlp -007, absolutely.

It looks like a very well done experiment, and the results are in line with my experience with the yeast strain.  However, for English strains such as WLP002… a more dramatic difference becomes apparent.

At 55-58… fairly clean.  (Clean enough the Bud drinkers in my family think the cream ale is a lager) At 75…it gets very estery.    I often use WLP002 in my Jannets Brown recipe at 58 and get a very clean beer, I also use the yeast at 68 to 75 in my english ales… and like what I get there as well (very different! Much more fruity esters)

Good news is… if you want to brew Kolsh or clean ales,  this experiment clearly shows that WLP029 is a VERY forgiving yeast and will supply very clean characteristics over a wide range of temperatures… so if you don’t have a temp controlled fermentation, this yeast will certainly help provide clean beers at higher temps!

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 met Marshall the other day at Heretic Brewing. Offered myself up as a guinea pig for a different experiment. didn’t make it past the triangle test.

Exactly.

I’ve seen many’a poor habit start from jumping to conclusions based on one data point. A few posts have already shown that folks would like to do the same base on this experiment.

Please don’t do that.

Great beer is made with great fermentation control. Fermentation temperature, oxygen availability, and a proper amount of healthy cells. This is not a homebrewing myth.

What we are seeing at play in this experiment is what I mentioned in the “RPM” thread about picking a strain for the task at hand, not tricking a strain into performing the task at hand.

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.

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.

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.

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”

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

Nah, no thanks.  :slight_smile: