[cestrada]

I'm always curious to taste each element and sample stages to better understand how my "end result's" journey came to fruition.  This being said, I came across this last night:

4 Days into bottle conditioning, my NEIPA has a "blue cheese" flavor to it that was not there before.  When I sampled this on bottling day, it smelled and tasted amazing.  I am hoping it is my persistent curiosity that is hitting me over the head.

Here are a few quick stats:

5.5 Gal
Brewed, pitched (Wyeast 1318 London Ale, 2L starter), attenuated 85% ~ 5 Days.
5 Days In, Added Pasteurized Mango;
Dry hopped with 'new' hop sock - 5 Days
Removed hops, 2nd Dry hopped with 'new' hop sock - 5 Days
Removed hops and Mango, cold crashed over night.
~15 Days, Bottled.

So, here I am on day 19(ish) with my dilemma.  At each point, I would sample the beer and I was very pleased with the outcome.  Needless to say, it never remotely gave off a flavor or aroma of cheese.

I am pretty OCD and I am a stickler for sanitation and have never came across this yet.

The only theories I had were:
1)  My beer is ruined!  Cue the waterworks, this man is going to cry.
2)  The yeast is still at work and this is just green

Any thoughts are greatly appreciated.  Thanks!

[kramerog]

I'm wondering if you are encountering isovaleric acid from old hops.  I have only encountered isovaleric acid in taste tests.

[cestrada]

I'm wondering if you are encountering isovaleric acid from old hops.  I have only encountered isovaleric acid in taste tests.

This ran across my mind as well, but I dismissed it initially because these were supposedly still fresh, climate controlled hops.  On my part, I always keep them in their vacuum sealed bags in a freezer.

But now that you brought this back up into the possibility-mix, it's entirely plausible that these could have actually been old, or mishandled/improperly stored hops prior to my purchasing. 

Le Sigh... 

[Robert]

Doesn't isovaleric acid break down to fruity esters in fermentation, or am I thinking of some other cheesy fatty acid?  If I'm right, might not time solve the problem?

[kramerog]

Brett can turn isovaleric acid into ethyl isovalerate according to Milk the Funk: http://www.milkthefunk.com/wiki/Isovaleric_Acid.

The IPA can become a Brett project or may already be one.  Having done a Brett project with beer that had a lot of butyric acid, the result was more interesting than good.

[cestrada]

Thanks for the link Kramerog.  A very good read.

I’m hoping, like Robert mentioned, it wears off in time (the shorter the better since this is a NEIPA).

I had my wife taste it and she said she could not detect the flavor or aroma. I’ve read that a certain % of people don’t pick up the isovaleric acid.

In any case, I will revisit this in a few more days when I give it another taste.

[cestrada]

Update:

3 Days further into conditioning, the isoloveric acid flavor pacified.

I’m not quite sure if it was the yeast that continued to nurture the mango, or perhaps some other factor.

While I am elated that I didn’t actually ruin this brew, I am now stuck wondering how this flavor and aroma was so prevalent only a few days ago, and now it is completely gone.

I’ll provide another update in a few more days again.

Cheers! 🍺

[802Chris]

Over the last six years brewing I have learned the following...

yeast and wort make beer

sanitation and time make good beer

I am forced to relearn this constantly as I am the laziest and most impatient brewer you could imagine.