Very sour beer. What could cause it?

[gobuchul]

I did a batch of Chinook/Columbus IPA, quite bitter at about 45IBU.

I had problems with a blocked filter and ended up scooping the wort out of the boiler and filter through a mesh bag into the FV. Not ideal I know!

There was a lot of trub in the FV and I also ended up leaving it on the yeast for over 3 weeks.

It smelt fine when I kegged it but when I have come to drank it, it's incredibly sour. It has an unpleasant acidic flavour, not harsh but very sour. Hard to describe.

Any ideas where the source of the sourness may of come from?

[Jim]

Sounds like an infection to me (unfortunately).

[gobuchul]

Jim - I think you're right. It was a 40 litre batch. Fermented in 2 different FV's in the same fridge.

Just tried the other keg and it's fine.

At least I've only lost 20 litres of precious beer.

[Wonkydonkey]

That's one of the good things with splitting the batch, you can almost pinpoint where the infection got in,
Sounds to me the FV is the place, but I don't know if it was lack of cleaning, or some bit of dust jumping in while you were busy looking the other way
But like you say all is not lost. I've had 2 infections like this.

I normally just guzzle the infected brew, if I can and its not to bad (the last one made me fart like crazy, lol .so I drunk it. The nite before I went shopping)

Cheers
WD

[orlando]

Acetobacter/lacto bacillus. The latter clings to grain, every time you pour grain into a container you may well have noticed a fine cloud rising up. Attached to each fine particle will be lacto bacillus. On the hot side, not usually a problem, on the cold side it can come into its own. One reason I'm not a fan of crushing my own grain, would have to do it in a different room to brewing. The "scooping" is possibly the cause, not trub or leaving on yeast for 3 weeks. Doesn't explain one 1/2 being OK rather than other, so I would be inclined to bleach both or renew before your next batch.

[Jocky]

I had problems with a blocked filter and ended up scooping the wort out of the boiler and filter through a mesh bag into the FV.

The bag is the sort of thing that screams infection source. What did you previously use the bag for - as others have hinted at, grain is a big source of lactobacillus, so if the bag has previously had grain in it then I'd be suspicious of that.

[gobuchul]

I didn't know that about grain as a source of lacto bacillus.

I guess that was the source as I store and measure my grain in the same shed I brew in. Guess I will change that.

Must of come from one of the FV's, as that was the only difference, or possibly the corny?

[orlando]

Must of come from one of the FV's, as that was the only difference, or possibly the corny?

My conclusion too, but the other comments I made could be pertinent for other reasons.

[Stewb]

Acetobacter/lacto bacillus. The latter clings to grain, every time you pour grain into a container you may well have noticed a fine cloud rising up. Attached to each fine particle will be lacto bacillus. On the hot side, not usually a problem, on the cold side it can come into its own. One reason I'm not a fan of crushing my own grain, would have to do it in a different room to brewing. The "scooping" is possibly the cause, not trub or leaving on yeast for 3 weeks. Doesn't explain one 1/2 being OK rather than other, so I would be inclined to bleach both or renew before your next batch.

I did not know this- and very interesting as i always weigh out my mask ingredients in brew area- probably more by luck than judgement the fermenter is sealed, but I'm always cleaning that powder off surfaces as it settles in brew day.

Given this thread may switch to doing it in kitchen or outside in good weather!

Sent from my Nexus 5X using Tapatalk

[orlando]

Acetobacter/lacto bacillus. The latter clings to grain, every time you pour grain into a container you may well have noticed a fine cloud rising up. Attached to each fine particle will be lacto bacillus. On the hot side, not usually a problem, on the cold side it can come into its own. One reason I'm not a fan of crushing my own grain, would have to do it in a different room to brewing. The "scooping" is possibly the cause, not trub or leaving on yeast for 3 weeks. Doesn't explain one 1/2 being OK rather than other, so I would be inclined to bleach both or renew before your next batch.

I did not know this- and very interesting as i always weigh out my mask ingredients in brew area- probably more by luck than judgement the fermenter is sealed, but I'm always cleaning that powder off surfaces as it settles in brew day.

Given this thread may switch to doing it in kitchen or outside in good weather!

Sent from my Nexus 5X using Tapatalk

You can discover this yourself by mashing in as usual and letting it go cold, voila (intentional use ), you have just made the base wort you need for a sour beer. I've said it many times, "foreign" brewing, aka the continent, has a lot of beers based on brewing "faults".