Naked Science Forum

Non Life Sciences => Chemistry => Topic started by: launcherofcats on 12/09/2012 05:39:41

Title: Why do my fruit juices become carbonated in the fridge?
Post by: launcherofcats on 12/09/2012 05:39:41

I read a topic on this site about orange juice doing this.  It's fermentation, you gotta throw it out.  Ok, fine. 

It keeps happening.

What gives?  Is it something with the fridge?  I'm storing them normally--go straight home, put in refrigerator.  A few days later, the juice is undrinkable.  It's happened with apple juice, orange juice, and carrot juice, with different brands.  Getting tired of throwing all my drinks away.  What conditions could be present that would cause fermentation so regularly?

Thanks!

Title: Re: All my fruit juices in the fridge become carbonated
Post by: neilep on 12/09/2012 05:57:15

Are you buying the organic stuff or freshly squeezed stuff because I suspect this has a shorter life span and thus the fermentation process kicks in sooner !...Just a thought !...especially if you have opened it and then left it for a few days too !

Welcome to the site.

Title: Re: All my fruit juices in the fridge become carbonated
Post by: launcherofcats on 12/09/2012 06:15:35

I know organic has a shorter lifespan, but...two days?  That can't be right.

Title: Re: All my fruit juices in the fridge become carbonated
Post by: RD on 12/09/2012 09:07:48

Quote from: launcherofcats on 12/09/2012 05:39:41

... What conditions could be present that would cause fermentation so regularly?

The fridge may not be cool enough, (should be between 3 and 5 Celsius ), e.g caused by door seals leaking due to old age.

https://www.google.co.uk/search?q=fridge+thermometer


If someone is drinking directly from the fruit juice carton that could cause the juice to "go off" quicker by contaminating it with microorganisms from their mouth, e.g. yeast. 

 

Title: Re: All my fruit juices in the fridge become carbonated
Post by: launcherofcats on 12/09/2012 22:03:19

As a bachelor, I certainly do drink straight from the carton.  I'll stop.  Had no idea that could possibly relate to that.

And it IS an old fridge, I'll look into the temperature.  Thank you very much!

Title: Re: All my fruit juices in the fridge become carbonated
Post by: evan_au on 14/09/2012 11:43:34

There is a style of beer in Belgium using wild fermentation - it uses yeast in the ambient environment.  http://en.wikipedia.org/wiki/Lambic

Without vouching for its authenticity: When I was living in Belgium, I heard a story about a brewery that had renovated its roof - and the beer stopped brewing. They then reinstalled some of the original tiles under the new roof, and the beer started happening again...  It seems that over the years, the tiles had continuously absorbed and released enough yeast spores to keep the brew going.

In your case, wild fermentation is an undesirable outcome, so I recommend that you give your fridge a good scrub-down with bleach (or get a new fridge...).