Banana esters in Oktoberfest

I made the oktoberfest kit from midwest, but used S-04 yeast due to the lack of fridge space for lagering. Today I cracked my first bottle and found that it had the slightest banana esters...more of an aroma than actual taste. Will this diminish over time, or is it permanent? It doesn't make the beer bad by any means, just wondering if I should let it bottle condition for another month or two? Also, is this a byproduct of using an ale yeast for a beer that's traditionally lagered, or was it a mistake during the brewing process?

What were your temps like, pitching, fermenting, etc.?

I pitched at 70, but it may have fermented at a similar temp. The house thermostats are set set at 68, but fermenting took place in the room with tje fish tank which usually runs a few degrees warmer.

either an error in fermenting temps, left in ferementer to long or contaminated somewhere along the way. I have had a couple come out this way as well and in the end it was contamination from by bottling bucket spiqot. wait a few weeek and sample again if taste is going to subside you will definatly know by this time. Also you mentioned that it doesnt taste bad..a word of caution i drank a few of mine that came out this way as well and found out that the beer gives back.....in form of pounding headache

Higher ferment temps can lead to those esters. Remember too that fermentation is exothermic, so outside temp at 70 could be 75 in the bucket. Aging should help diminish some of those flavors, but better controlling temps next time will help avoid it. Can you rig up a swamp cooler?

I have ran into the same issue however my room temp was in the low 60's and the fermentation temp was 70-72. Getting ready for the next brew and trying to keep this from happening again.

Could the higher fermentation temp been caused by my screw up of only having 4 gallons of wort instead of 5? I had an OG of 1.068 and the WLP380 vial was out for 3 hours prior to pitching

Thanks

My first batch tastes like a big ol' banana too, honestly isn't too bad but definitely wouldn't serve it to somebody. I think about going with it and putting a slice of banana on the bottle and call it a banana nut ale.

As others have said, it's esters from the yeast. Some are cleaner than others but generally speaking the higher you go in a yeast's recommended temp range, the more esters will be produced. That's a good thing when brewing most Belgian beers but not so good when trying to brew something like an Oktoberfest. Try fermenting cooler next time.

microbusbrewery said:

As others have said, it's esters from the yeast. Some are cleaner than others but generally speaking the higher you go in a yeast's recommended temp range, the more esters will be produced. That's a good thing when brewing most Belgian beers but not so good when trying to brew something like an Oktoberfest. Try fermenting cooler next time.

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S04 especially is fruity (in a bad way) when fermented over 64 or so. Some ale yeast strains stay "cleaner" up to about 70/72, like WLP001.

For a beer like an Oktoberfest, which is a lager, using ale yeast and fermenting warm usually means the beer will be drinkable but not taste like an Oktoberfest. I've found that there are a couple of ale yeast strains that can make a "mocktoberfest"- fairly close to a lager in mouthfeel and flavor. That is pacman ale yeast (from Wyeast), fermented at 60 degrees, or nottingham ale yeast fermented at 57-62 degrees. Kolsch yeast may work also.

Thank you. I may have to go to the garage and get one of those heating belts and controller.