Acid beer?

[Keat]

hello all
I've been having a problem recently, and I'm seeking advice and help. I've done about 5 batches of AG now, and they've been fine. But the most recent AG pale ale was really acidic and leaves a prickly, burning sensation on the tongue. I'm very sure it wasn't an infection because I didn't detect any off-flavours, and it tasted fine. I attributed it to tannin extraction during my mash, as I have very soft water. BUT, I did a batch of extract after that, and encountered the same problem (although not as acidic, but still there). Below is my local water analysis:

Calcium (as Ca) 20-40 mg/l
Sodium (as Na) 10-30 mg/l
Chloride (as Cl) 35-100 mg/l
Sulphate (as SO4) 30-60 mg/l
Magnesium (as Mg) 1-5 mg/l

So does anyone have any suggestion or advice to figure out what I'm doing wrong? Help! Thanks!

[DannyW]

Is it overcarbonated? High CO2 levels will lower pH and give you a prickly burn.

Did the fermentation appear normal? Was the krausen particularly dense and matted or ropy?

Perhaps an obvious question, but did you treat your water for either batch? If you think you are adding 30% phosphoric acid and really added 88% lactic you would certainly notice a difference.

What is the source of your yeast? Was this a fresh pack or a repitch? How many repitches?

Did you empty all the StarSan out of the fementer? Ask Justin about the lovely acid brightness a couple of gallons of that will give you!

[Keat]

Is it overcarbonated? High CO2 levels will lower pH and give you a prickly burn.

Nope, I'm using the Tap-A-Draft and force carbonating at 15psi. Even the bottles that are not yet carbonated have the same problem.

Did the fermentation appear normal? Was the krausen particularly dense and matted or ropy?

yup, everything looks normal, nothing unusual

Perhaps an obvious question, but did you treat your water for either batch? If you think you are adding 30% phosphoric acid and really added 88% lactic you would certainly notice a difference.

Nope, didn't treat the water for either.

What is the source of your yeast? Was this a fresh pack or a repitch? How many repitches?

I'm using US-56 dried yeast. I'm into the 4th re-pitch. Would that be a problem?

Did you empty all the StarSan out of the fementer? Ask Justin about the lovely acid brightness a couple of gallons of that will give you!

Emptied as much as I could, there were some foam left though.

[DannyW]

What is the source of your yeast? Was this a fresh pack or a repitch? How many repitches?

I'm using US-56 dried yeast. I'm into the 4th re-pitch. Would that be a problem?

Maybe. Depending on your techniques and local microorganisms, you might be collecting more and more of something you don't want (wild yeast or lactobacillus maybe).

As a first step, I'd try another batch and pitch a packet of fresh yeast and see if the problem persists.

[SunkenBier]

I would agree on the yeast too but I would also carry it into an experiment. Use some of the old yeast in a 1 gallon fermentor and see how it differs from the main portion that you use fresh yeast.

[Keat]

Ok I'll try with a new pack of yeasts. I was going to do that anyway, I dumped the old yeast with the last batch.