What's with the bananas

[Luthierzan]

Ok so I took 2 attempts at belgian blonde ale using extracts following jamils lefty recipe in his book. I fermented it at my apartment with Wyeast Belgium Abbey II yeast at temperature of 69-70F. Both had so much banana flavours in them they were pretty much undrinkable.
I just moved into all grain and brewed the Shakespear Stout with PacMan yeast. it came out beautiful...I was so happy.
I then made a Saison AG using Jamil's instructions and recipe from his show using wyeast saison yeast and strict temperature control starting at 67 and moving up to 82 at the end. During th fermentation I sampled it and I was really happy with the development of lemon and pepper notes. It is now finished and I have the carboy clearing at 58F. I tasted it and there is a bit of banana again!
Where the hell is it coming from? Any ideas? I seem to only get it with Belgians.

[Evan B]

possibly underpitching yeast? you can get those esters from stressing the yeast in the early stages of fermentation

[Luthierzan]

HMMM interesting.
I did make a couple of starters, but unfortunately my homebrew store only carries the wyeast "propogator"(25 billion) packs rather than the "activator" (100 billion) packs so I always make a couple of starers. Maybe it still isn't enough.

Thanks
David Oh

[mookie1010]

I've had a few beers with a banana note to them - both of them were extract beers that under-attenuated to a degree. How well did yours dry out?

Both mine were fermented at 68*F with 1056.

[Spelt]

Inadequate aeration of your wort may also give you significant banana flavors. I have to peel my current IPA to drink it and I'm pretty sure it was because excessive beverage consumption at brew time resulted in my forgetting to aerate.

[Petedadink]

I was just about to say Spelt. Inadequate aeration.

[Evan B]

[ipaisay]

Try fermenting at a much lower temperature like 62-67 degrees F. If you are doing 5 or 10 gallons this lower temps will favor more phenolics and less esters. You are having troubles with too much of the banana esters. The commercial breweries will tell you their fermentation temps (70+) but understand this, they are fermenting in TALL and rather large fermentors where the vertical height is much greater than the width. Therefore, they are getting more pressure on the yeast and that allows them to express more phenolics vs esters out of their yeasts. Your 5 or 10 gallon fermentors have a greater width to height ratio versus the commercial norm of tall conicals which will put less pressure on homebrewed yeast causing an expression of esters to phenolics. Think of the fruity esters that are traditionally produced with square fermentors of English breweries (think Sam Smiths), short and squatty.

I always ferment my belgian beers around 62 to 66 degrees and the bubblegum and bananas are very much subdued. This 62 degree temp is also great for German Wheats as well. Or ferment in a corny keg at higher temps to mimic the commercial breweries.

Always pitch the right amount of HEALTHY yeast too.