Oatmeal stout...twang?

[stavale8099]

7.5lb maris otter
1lb instant oats (day before I baked @ 375 for an hour - nice and toasty)
0.5lb flaked barley
0.5lb chocolate
0.5lb crystal 60L
0.2lb carapils
0.2lb roasted barley
2oz East kent 60 min.
single temp infusion @ ~154
S-04 yeast

If you'd like more background of the actual brewing experience you can click here https://www.homebrewtalk.com/f36/my-first-ag-brew-fun-392811/

Otherwise, here's my new dilema that'd like some input on!
So, when I brewed this it took a solid 3-4 days before there was any fermentation, which is fine. No kareusen, nothing in the bubbler during ferm. that's fine too.
Anyways, so it's been 4 weeks in primary fermentor and today we decided to rack it. It doesn't look contaminated - it had a beautiful color and even had a good smell. However after tasting it it had a real sharp almost licorice-taste. Very sharp. It was a 5 gallon batch and after getting down to the trub there was probably a good .75 gallons of it.

My question is, do you think this taste will condition-out after racking it or does the twang-taste remind you of something that may have gone wrong in the brewing process? I tasted it probably 2 weeks ago after fermentation had completed and it had the same taste but I thought it was probably hops that still had to mellow out.

Thoughts?

Thanks!

 

[zachattack]

What temperature did you ferment at? A lot of people don't like S-04 because it can give a "twangy" off flavor if you don't ferment it on the cooler side. It seems like it really bothers some people, others think it's fine. There are a few threads about it, here's one:

https://www.homebrewtalk.com/f163/not-loving-s-04-a-363641/

 

[stavale8099]

it fermented between 60-65 degrees the entire time. The taste is "not right" but I'm convinced it's not contamination. Thanks for the thread - I'll check it out right now...

 

[Yooper]

I'll second the S04 as a culprit. It gets weirdly twangy if it gets above 65 degrees or so. But usually it starts (and ends) quickly, so if it took 4 days to start going, it makes me think that the yeast was very stressed and that could be the cause of the flavor and not a too-high fermentation temperature.

The other thing I thought of is water chemistry. If the brewing water had low alkalinity, the mash pH could have been pretty low, and that can cause a little bit of a tart finish.

 

[stavale8099]

Thanks for the input - the mash pH was around 5.5 if I remember correctly. Yeah the yeast did take a while to get going - I figured it was because I did not have enough zinc or something although I did throw in some dry yeast to the boil to provide the fresh yeast nutrients (when I pitched @ 75oF). I would have loved to used a smack pack but the brewery store was fresh out and S-04 was recommended as a backup. I pitched it dry. Weird was it sunk instead of rehydrating on the surface. Like I mentioned, the kareusen was almost nil, too. Seemed the opposite of most people's experiences with S04. D'oh.