sourness has gotten much stronger....

so, I brewed a Porter on 11/18/2009. been in the primary until yesterday.

ever since my first gravity reading at 10 days, I noted some light sourness, but i wasn't sure because it generally went away. after that my notes say it tastes great.

I lifted the lid to keg it yesterday, and the smell was very bad. i figure it's just the krausen ring that's been sitting for over a month. so i rack to the keg, chill, and take a sample. yeah it wasn't carbed, but i wanted to take a taste. unfortunately, the sourness is more pronounced than ever.

what causes this? infection? improper temps? I double-pitched WL001, and fermented high 60's.

the strangest thing (to me, anyway) was when i opened the lid, i saw the clean surface of the beer. normally i saw a krausen layer.

Temps sound fine. Possibly an infection but I wouldn't jump straight to that. I would say just let it set for a while and see how it develops. What's your recipe?

here's the brew log:

https://www.homebrewtalk.com/f36/1st-ag-finished-about-1-30am-147759/#post1687614

it tasted so good coming right from the boil kettle, but when i opened the fermenter lid yesterday, it was a bad smell. not rotten eggy, not really vinegar-y...just bad.....

Sounds like a lacto infection. Tastes almost fizzy-sour. Like sourdough bread.

I've had a few of those. They don't improve.

Normal cause is the introduction of grain dust into your wort.

darn. probably the cause.

arg, i was really excited for this. oh well, have to brew it again.

While sometimes dark roasted malt flavor can be confused for sourness (like in the way that coffee might seem sour) and roasted malts can lower finished beer pH (but not likely to a level that you would call "sour"), the fact that it got much worse pretty much seals it as an infection.

I say if you like it, keep it cold and drink it fast and call it "historic porter".

If you don't like it, I would personally get rid of it unless you really don't need an extra carboy/keg/space/etc.

Is the sourness consistent with your experiences with lactic acid (berliner weiss, lambics, yogurt, naturally fermented pickles, sauerkraut, kimchi etc), or acetic acid (la folie, rodenbach, quick pickles, most store bought pickles, vinegar)? Does it seem more like a really harsh cup of coffee. The latter would indicate to me not sourness but either overuse of roasted grains or poor water chemistry. I still doubt this explanation as it should not get much worse over time.

I don't mind harsh coffee at all, so I know and am ok with that taste. this is what I thought it was at first, since when I chilled it it went away.

I really can't put a finger on the smell. it's definitely not sulfur, not really vinegar...i really don't know. i'll have to take a hard tasting of it tonight. i'm not terribly familiar with lactic acid tastes, so maybe that's it.

motobrewer said:

I don't mind harsh coffee at all, so I know and am ok with that taste. this is what I thought it was at first, since when I chilled it it went away.

I really can't put a finger on the smell. it's definitely not sulfur, not really vinegar...i really don't know. i'll have to take a hard tasting of it tonight. i'm not terribly familiar with lactic acid tastes, so maybe that's it.

Click to expand...

I'm not sure I can explain lactic sourness other than that it is softer than acetic sourness.

If you have a change to pick up a berliner weiss (1809 is widely distributed), thats probably the purest expression of lactic acid in beer. Lambics are also lactic sourness but also have brett character.

You could try using campden to kill the infection and something like blackberry to mask the sour.

tried it again. most probably lactic acid. so sad

this was for a new years party....

lesson learned I guess.

there is trub floating in the porter (looks like grain bits), could this be an issue?