Fermentation of juice drink

[Sweet G]

Hello, I bought a bottle of still pineapple juice today and gave it a good shake before I opened it. When I did, it tasted kind of fizzy and I noticed minute bubbles rising to the top. I drank it anyway (it was well inside the expiry date - Feb 06)and am still alive but wondered what would cause this to happen? and is it bad!? Cheers.

[CiderMonkey]

I've noticed this happen sometimes with orange and apple juice I have had. I have no idea why it happens though

[charliep88]

dont buy any green bananas

[Robinia]

Be warned - it may have a laxative effect!!

[WendyS]

Could be it's fermenting due to sugar in the product being exposed to air and a slight leak in the packaging.  If it happens again suggest you  write to the manufacturers and complain, quoting the batch number as it may have been faulty.  (And you might get a refun).