Off flavors? Some advice?

[daniel4616]

Okay, I recently pushed out my fifth batch of beer, which was all-grain. It is fermenting along with the previous back right now.

A month ago I did a Pils style ale, with 3lbs of Pils extract, and 3lbs of pils grain. This was a smaller batch. It just spent two weeks in the bottle for carbonation. I popped one open last night, and it had a distinct "cinnamon" after-taste. It wasnt overwhelming or disgusting, but I dont remember using any cinnamon, so Im at a loss as to why. I had pitched my yeast WAY to hot on the batch before this one, and made sure it was cooled enough before the yeast was pitched in. I used Munton's Gold, as my yeast for this Pils. Boil went perfect, kept everything clean (I think), and no obvious signs of contam or anything wrong during primary or secondary.

Because my last batch before this one was messed up and dumped, due to the phenols and high temp for pitching, I am sort of flipping out. Can someone please help me try and figure out how to avoid this?! Anyone have issues with Munton's Yeast? Also, both ales used the Munton's KreamyX, could that impart an off flavor because its not a normal sugar?

 

[JLem]

What temp did you ferment this at?

 

[daniel4616]

Ambient temp was 74F, I cooled this down to about 72F when I pitched the yeast. Beer was fermenting within 5 hours, and slowed down in about 3 days.

 

[JLem]

I don't know anything about that yeast but an ambient temp of 72 or 74 is too high in my book - fermentation is going to create heat as well so you were likely fermenting at 76-78 easily. This could very well be the source of the off flavor, though I hadn't heard of cinnamon-like aftertastes. But I suppose that could fall under the spicy, clovey phenolic description.

 

[daniel4616]

I see. The profile temp says 65-78F. Would you happen to have any suggestions to get my temp down a little lower? Maybe a fan or something would help?

 

[SnallygasterBrewery]

To control fermentation temp on the cheap it can be a little more labor intensive (but at least you can save some bucks). Like JLem said, the ambient temperature doesn't accurately reflect the temp inside the fermentor. The yeast are basically little furnaces during fermentation, burning up the sugars. You could try putting it in a tub of water, draping a towel around the fermentor and placing a bit of the towel in the water to carry moisture up and wick away some of the heat. Load up the tub with some frozen 2 liter bottles and switch them out now and again once they melt (I don't know the specifics of how much -- it's trial and error). I know there are threads about different ways to keep temps down, you'll just have to do a little research.

A strip thermometer is cheap and pretty effective at monitoring temps. Run it sideways in the middle rather than up and down to get a more accurate reading. Towards the end of fermentation (about the last 1/4 of it) you can let the fermentor warm up a little bit to mitigate some of the off-flavors. I know a lot of people here are fans of the long primary and I gotta say if you have proper pitching rates, good temps... that's the way to go.

 

[daniel4616]

Wow, thats great advice, and I will try that out.
Thanks a ton!

On a side note, is it not possible the yeast or priming agent are contributing factors? Iv read a little on here that say Munton's isnt the way to go, then some say its the best all purpose yeast? Anyone care to chime in?

 

[Toga]

I'd have to say the best all around yeasts to use would be Safale US-05 or Nottingham for any ale where you want little flavor imparted by the yeast.

 

[JLem]

Wow, thats great advice, and I will try that out.
Thanks a ton!

On a side note, is it not possible the yeast or priming agent are contributing factors? Iv read a little on here that say Munton's isnt the way to go, then some say its the best all purpose yeast? Anyone care to chime in?

It is likely a combination of the yeast and the temp. Some yeast behave better than others at higher temps, though a general rule is that the higher the temp the more esters (and phenols?) are produced regardless of the yeast. If the yeast is already a strain that produces these compounds at high levels, an elevated temp will be even more detrimental (assuming you want to avoid an excessive amount of these compounds). I have no experience with muntons yeast but my impression is that it is cheap stuff and rather low on the quality scale. If so, I would imagine it does not behave nicely at warm temps.

Here's some basic info on the importance of temperature during fermentation - http://www.howtobrew.com/section1/chapter8-1-3.html

 

[SnallygasterBrewery]

Like JLem suggested, definitely keep quality in mind along with propagation and fermentation control when you're dealing with your yeast. Proper aeration with good pitching rates and temperature control will help stave off undesirable compounds (especially esters). Remember to let the yeast clean up after themselves after their exponential growth (White and Zainasheff recommend warming up the temps by a few degrees towards the last 1/4 of the fermentation to keep the yeast active and scavenging). Other than that, just research the strain you're planning on using and keep things clean and sanitary. :rockin: Keep on brewin'!