Why did my Juice turned to Wine?

I try to drink lots of water every day, at least 90 ounces.  Usually, I reward myself with a glass of tea with a little juice to flavor it.

I felt like I wasn't getting enough water or something was causing me to dehydrate.  After some research, I decided to give up the tea and juice since I read that tea might be the problem.

I thought it had been a couple of weeks drinking nothing but water.  I decided to give myself a treat with a half glass of juice.

My juice had turned to wine!  Why?

It was store brand juice and a blend of apple and cherry. Not 100% juice.

Also the plastic bottle swells and I have to open it every so often to relieve the pressure.  Just like with my homemade wine.

Yeast from the air naturally fermented the juice.

My brother had this experience with his young daughter.  Bottle of apple juice left out on the counter that should have been refrigerated.  Young girl kept going back to get a few glasses after a meal.  She started acting a little goofy.  He sniffs the container and tries a splash.  They had accidentally created apple jax by not refrigerating the juice.  

Your juice got 'contaminated' with the homemade wine yeast that you have floating in the air around your house. Those yeast then started multiplying and producing alcohol.

Be careful the 'juice' could have more than just yeast in it multiplying.

Normally if you finish your juice within 5days of opening it. The preservatives in it will keep the yeast and other microbes population low, esp in the fridge with low temperature. But if you had taken a break and let the juice stay in the fridge for 10+days or you had taken it from outside the fridge with the near freezing temp, the yeast will proliferate and make alcohol.

Also you dont need special grape juice or any juice to make alcohol. Just sugar and water. The sugars can come from any fruit, or even flour/barley (beer), sugarcane (rum), potatoes(vodka) or rice(sake).

Thanks, that explains it.  I would never expect this to happen.

I have had juice go "bad", can't remember the results other than maybe a sour smell.

I was sure shocked when I took a sip.

Hi Anne,

You make this sound like it's a bad thing.

No, it is not a bad thing. Sorry if I came off that way.

I like wine occasionally, mainly for special occasions.

I like to experiment with some things, like winemaking, liquors, infusions, etc.

when i worked at a natural grocery, we would frequently get juices and ciders that would start fermenting and puffing up, even awhile before their 'sell-by' date, and never opened. i brought more than a few home to fortify a little extra with honey and get them under an airlock.

I've had something similar happen with some apple juice from the store. One night I forgot to put it back in the refrigerator and left the bottle on the counter until the next morning, then put it back in the fridge. Few days later I went to pour another glass and noticed it was fizzy, so I smelled and tasted it.
It actually was pretty good; considering it was made from a $1 bottle of apple juice