Slight sourness in my beer

I brewed a Stout with fuggle hops, everything went text book with sanitation, I made sure everything was sanitized etc. I had new racking tubes with this batch, however, I noticed a slight tinge of sourness in my beer. It wasn't pervasive at all but I noticed an extra sourness at the end of my tongue. I smelled the beer, it smelled like fuggles but I wasn't expecting that sour tang at the end of it.

I bottled this beer three weeks ago, its only been sitting in my fridge for a couple of days. I got a little worried because I gave a professor and a close friend a beer without me trying it. The fermentation looked normal, nothing out of the ordinary.

Is this slight sourness something I should be worried about? Meaning call them up and tell them not to drink the brew or is it a product of a green beer? Thanks guys.

By sour, do you mean like sour milk or astringent, like sour bitter? I've had stouts that gave me a sour astringent taste on the back of my tongue from the roasted malts... I've since started adding them at the mash-out.

Sour bitter tasting.. It has a slightly sour aroma.. however, it doesn't smell rotten by any means and its barely discernible. I'm just wondering whether or not it could be infected or that the Stout has some sour qualities that I didn't know about prior to brewing.

You may have already seen this, but if not, it may help.

How to Brew - By John Palmer - Common Off-Flavors

maffewl said:

You may have already seen this, but if not, it may help.

How to Brew - By John Palmer - Common Off-Flavors

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Interesting link, but he never mentions the word sour..

Just to clarify, and I don't intend to nitpick, but sour and bitter are not the same, Sour-Bitter Confusion | Sensory Science

The only reason I bring this up is as the above linked article indicates, there tends to be some confusion in the sour/bitter arena. For example, I had a co-worker tell me he didn't like lambic beers because they were too "bitter". I told him they're not bitter, they're sour. He asked what the difference was and I told him to compare an Imperial IPA (bitter) to a lambic (sour).

I agree with the previous comments... some people get sour-bitter and sour-well... sour, confused. Which is why I asked...

maffewl said:

By sour, do you mean like sour milk or astringent, like sour bitter?

Click to expand...

To which the answer was...

shattstar03 said:

Sour bitter tasting..

Click to expand...

That is why I posted the link, hoping it would help the OP to narrow down the causes. If it's none of those and it still tastes "sour", it could very well be a contamination. However, it sounds like a roasted malt astringency to me.