Sour beer

[freflow]

Hi, I have started drinking my Milestone Black Pearl Irish Stout and it tastes sour! I have brewed this many times before and it never tasted like this. I have followed all hygiene protocols, it had and has only naturally produced gas in the barrel and was not opened after filling the barrel, it tasted fine when first filling the barrel, as it always tastes, as a young beer, just finished fermenting. it is only about 1 month old but never tasted like this before. I have been a homebrewer on and of for 20 years, never had any wine or beer go off on me, so I am stumped. is it drinkable, say with lemonade, is there any trick I can do to turn back to a more pleasant taste of stout, or is it spoilt (off) and should be tossed? are there tests I can do to check if it is safe to drink?
Any opinion welcome.
Thanks

 

[strange-steve]

If it tastes properly sour then it's probably a lacto contamination (assuming it's not vinegary that is). Unfortunately there's not really anything you can do to reverse this, but in some rare occurrences wild lacto bugs can actually add some very pleasant flavours. If you haven't been that lucky and it's unpleasant then it's unlikely to get better, so it's up to you whether it's worth drinking or dumping it. Don't worry about safety, it's not dangerous to drink.