I know that banana flavors usually comes from esters that are released due to hot fermentation temps. In this case I don't think that is why because I brewed a french style saison and fermented it around 72 degrees. Here is my recipe and I am wondering if anyone has any thoughts. It is pretty much old socks saison recipe with slight changes here and there. 86% Belgian Pilsner 11.6% Wheat Malt 2.4% Acid Malt I used Czech Saaz malt with RO water that I added calcium chloride to as well as whirlflock tablets and yeast nutrient. The OG was 1.050 and the FG was 1.002. I didn't make a yeast starter and I am wondering if under attenuation could be a cause for the banana flavor. I brewed three weeks ago and kegged last night. I have only had a sip, but the banana flavor is definitely present. The banana is strong on the nose, but the taste is mild although still present. Is it possible the banana taste will go away if I cold condition it? Any help would be great. Thanks
The esters are produced from stress factors on the yeast, temperature can be one of those factors, under pitching is another. No starter would lead me to believe that this is probably your factor, as well as many Belgian yeasts throw more esters than other strains. Underattenuation isn't an issue since you are at 1.002 FG.
Thanks for the feedback. I probably should have specified. I am using 3711, not sure that makes a huge difference. I knew I couldn't get my temp up to the 80s during fermentation, so I used the french saison since it can successfully ferment at lower temps.
I'm thinking a combination of under-pitching and a slightly high temp for 3711. You said you fermented at 72 degrees, if that was the ambient temp, the beer could have been fermenting much higher than that. I had a Belgian Tripel that I fermented a little too high with 3787 (notorious for kicking up banana at high temps). But, with some age on it the banana mellowed out.
So can the other strains. I assume you're referring to Wyeast 3724. My experience has been that 3724 does not have to go above 80F to finish. It just takes patience. Having said that, none of the saison strains ought to be throwing a ton of banana. Pitch rate and temp probably contributed.
I used wyeast 3711 for the strain. I am thinking more and more that it was my pitch rate. That being said as a new brewer, this being my 4th beer I am still a little confused how my pitch rate can be low, but I reached the desire FG of 1.002.
There are several pitch rate calculators out there. Mr Malty and YeastCalc are very popular. There's also a yeast calculator embedded in BrewCipher, a general purpose intergrated brewing spreadsheet. (It's my sheet, and it includes work and inspiration from some others on the forum too). One thing BrewCipher has that others don't is a set of user adjustable parameters for things like desired pitch rate and yeast die-off rates. (But the default values are fairly similar to the values hard coded in the other popular calculators.) My advice is to choose a calculator and use it. The yeast manufacturers' recommendations ("pitch one package up to four months old into 5 gallons of wort up to 1.060 OG", or whatever) are dumbed down, binary, and are not rates at all. Someone will be along shortly to tell you that the assumptions in the Mr Malty calculator are conservative and wrong. But he won't be able to tell you what a "right" rate looks like.
Your pitch rate was at least a bit low (compared to a standard rate of 0.75 mil/mL/deg) because you did not make a starter. It could have been anywhere from really low to only a bit low. No real way to tell, although the date on the package might have given you some idea.
3711 will end up that low regardless of pitch rate. Most of the other saison strains will as well, if given enough time. Many folks intentionally underpitch saison yeast to stress it into making more esters. Some saison strains throw off a lot of esters no matter how you treat them. Some banana or bubblegum will express itself. It'll fade with time, don't worry about it.
I second what MrOH says about this, as this has been my experience with it and related yeast strains, too. Even under-pitched, any Belgian yeast strain has always powered through and never crapped out (failed to attenuate) on me. And when it is stressed, it brings out a lot of distinctive flavors.
There's good reason to believe many Belgian strains are closely related to hefe yeast, so I'm not surprised. In my experience the banana flavor is more determined by aeration rates than pitching, try adding more O2 next time.
