What does an infected beer taste like?

[fego]

I brewed an ESB a couple of weeks back when we had all that snow.

I went to bottle/barrel it tonight and noticed an odd looking scurvy on the top of it. I just drew some off to measure the SG which was 1.004, a tad lower than expected against an OG of 1060, so a strong brew.

I have never tasted anything like it though. It was really strong acidic taste like a lemony vinegar if I'm honest. At first I thought it was just green and the alcohol was overpowering, but I still can't get the horrible taste out of my mouth. I've never had an infection, but I think perhaps I have now.

Things I did different;
- used London Ale III yeast from an out of date smack pack which I had cultured up.
- used my shiney 50 litre FV, sterilised like I would have my plastic, but that was in use so I tried the shiney instead. The shiney has a lid which isn't airtight and too tempting to leave alone.
- I fermented it in the utility room. Temp was fairly constant but wasn't the same as by man fridge
- I dry hopped about 30g of EKG on day 3
- I roused the beer a few times using a plastic spoon that I had stored in Milton

Have I got an infection do you think? If I have, my money's on either the yeast or the lid being taken off all the time for good look/sniff...

[RobWalker]

Lemony is making me think ekg, but vinegary and loose lid is making me think infection...they are often pretty brutal though.

[EoinMag]

Loose lid means nothing. It'll be the rousing, at least that's where I'd lay money.

[fego]

Just a thought, I remember not remembering whether I treated the sparge water so may well have added twice the amount of CRS into the liquor. I also forgot the boiler salts. Could that have caused this taste?

Whatever it was, the beers undrinkable. 8 hours in the freezing for nothing!

[gregorach]

It was really strong acidic taste like a lemony vinegar if I'm honest.

Sounds like an acetobacter infection. Acetobacter is the beastie that turns alcohol into acetic acid - i.e. vinegar.

If I have, my money's on [...] the lid being taken off all the time for good look/sniff...

The would be my bet. Stop poking it! I've calculated spore fallout rates from exposing test plates, and I reckon that in a typical domestic setting with the usual diameter of FV, you're catching spores at the rate of at least one per second as long as the lid is off. And that's without your manky germ-ridden breath anywhere near it, or anybody shedding hair and skin flakes over it...

More generally though, infections can produce all sorts of off tastes. Acetobacter is just one of the more common ones. Lots of people who think they've never had infections actually have - infected beer isn't necessarily completely honking. (Actually, there's probably a few people out there who don't realise that their beer is always infected...) Any time you get a beer that just "isn't quite right", there's a good chance it's got a minor infection, especially if it gets worse over time.

Just a thought, I remember not remembering whether I treated the sparge water so may well have added twice the amount of CRS into the liquor. I also forgot the boiler salts. Could that have caused this taste?

Whatever it was, the beers undrinkable. 8 hours in the freezing for nothing!

Nah, water treatment mishaps are extremely unlikely to produce severe off-flavours. My money is definitely on an infection.

[boingy]

My money would be on the cultured up yeast. It's really easy to culture up other things along with the yeast, especially if you are starting with fewer cells than is ideal.

Whatever the cause, I'd say it's definitely infected so sadly there is only one course of action to be taken...

[Dr. Dextrin]

I'd say it depends on how much CRS you added. I suspect that with my very hard water if I added twice the CRS the beer might be undrinkably acid and taste as you've described. But OTOH, if you only have moderately hard water then I'd go with some sort of infection.

For reference, my CRS addition is normally around 30ml in 25 litres of liquor. So double that would be 60 ml.

[fego]

It's gawn back from whence it came. Back to the earth via the drain....

A bit odd though and difficult to work out exactly what when wrong though...

Poking it is highly likely although it was a double brew weekend and the other brew which I poked pretty much the same amount has turned out fine. The double dose of CRS might have been an issue but I remember tasting it last Thursday and I noted the taste as 'bang on' so not exactly definitely that. But it reminded me that I was tasting it to see if it would be ok to survive on the trub another few days because I went to Paris for the weekend meaning that perhaps it had sat for too long?

If thatvisnt the cause, then that leans the evidence towards the yeast. I cultured it in the airing cupboard which was probably way too hot and i ran out of spraymalt so used brewing sugar on the final step up. Hygiene may have been an issue there as well because it was all a bit rushed.

However, there's another possibility and that is the FV itself. This is the first time I've used this FV and the first time I've had an infection. Coincidence maybe, but I've done over 50 brews now so am no novice so am not convinced its not a coincidence. When I cleaned up tonight, I noticed the FV had some markings on the inside as if it had received corrosion of some sort. This is a standard 50 litre shiney remember so should be as smooth as the baby's proverbial. But it isn't. On rubbing it with my fingers, some of the corrosion transferred to my finger tips in a silver kind of dust. This might have been there already, or may have been caused by the acidic beer. I don't know because I've never used it before. One thing that crossed my mind was the outlet however. It's copper so I wonder if the beer reacted to sitting around a copper nut and tube for almost 3 weeks?

One tenuous suggestion could be my bottle of Milton. I used the remnants of a bottle tonight to sterilise a barrel. When I poured it, I couldn't help notice how wet and unsmelly it was. That made me think that perhaps it was just an old bottle rinsed out but not emptied and I had used the first half on the FV thinking it was full strength.

Either way, whatever it was, there's no denying I had a problem which serves me right really because I was only boasting the other day about never having had an infection.....

[gregorach]

Poking it is highly likely although it was a double brew weekend and the other brew which I poked pretty much the same amount has turned out fine.

Aye, but it's all a question of probabilities. You roll the dice - sometimes you get snake-eyes, but mostly you don't. Sounds like you've got a number of other potential problems though...