what gives beer a banana flavor

[hopsgrinder]

I had brewed an imperial IPA a few weeks ago and just out into a keg a couple days ago and was really excited and kisst wanted a taste. It was really good but there is a banana flavor in the brew. I did not use any yeast that gives any ester. So what gives it a banana flavor is that bad?

 

[luke2080]

Can you post your recipe, the yeast used, and mash temps?

 

[Lunchtime]

Quick answer...Monkey poop.

 

[HIM_Tattoos]

Bananas???

But in all reality, probably the warm temp you fermented at. Unless you put bananas in it.

and I officially curse you for getting that damn Gwen Stefani song stuck in my head......

 

[supe_kitchen]

Bananas???

But in all reality, probably the warm temp you fermented at. Unless you put bananas in it.

and I officially curse you for getting that damn Gwen Stefani song stuck in my head......

This ^ warm fermentation causes ester formation even in really clean fermenting yeast.

 

[QuickSilver08]

Isoamyl Acetate, an Ester Odorant.

I was actually just reading an article about this a few days ago.

http://www.dogfish.com/community/ne...r-a-day-keeps-the-butter-and-bananas-away.htm

 

[hopsgrinder]

Bananas???

But in all reality, probably the warm temp you fermented at. Unless you put bananas in it.

and I officially curse you for getting that damn Gwen Stefani song stuck in my head......

I curse you then for listening to bad music

 

[Yooper]

As others mentioned, ANY ale yeast will give you bananas (esters) when fermented too warm. Each strain is a bit different, so you might get bananas at 68 degrees for one strain, or 74 degrees for another, but in a "clean" well attenuating ale yeast once you get to about 72 degrees (beer temperature, not room temperature which may be significantly lower), you could get bananas. Or bubble gum.

 

[Yooper]

I was just thinking that another cause of banana flavor is underpitching/ stressed yeast. Even if fermentation temperatures are controlled, using only one vial of yeast (as an example) in an IIPA can cause stressed yeast and result in off flavors like esters.