Can chocolate go rancid/ taste off once opened- Please help !

Hi

I am trying to work with chocolate in a high humidity country. ( between 60 and 80 %) I was wondering what is the normal shelf life of chocolate once you open it from the manufacturers packet. I normally keep it well sealed in an air tight container and the room temp. is normally between 20-27 maximum. I know I may need to invest in cold storage for the chocolate. But, it has really been bothering me that once opened from the manufacturers pack , some of the chocolate has been tasting - a bit off- stale , gritty or old a bit like a closed attic - what is the reason for this ? This is also happening extremely fast - within 1-2 months of opening the package. The prodn. dates are around april or march this year with best before in 2013 for milk and dark 2014. How soon can chocolate taste off once opened. And any ideas why this ishappeningand ways to avoid it. Any help will be appreciated

ther is no dought that chocolate get spoiled wen exposed to humidity, avoid contact with air by foiling, or by keeping in air tight containers, or keep in closed room to avoid as much as humidity, nobody canot say how soon a chocolate will get spoiled it depends on humidity , presecnce of microbs and other parameters.

lt depends on even the brand, try changing your brand, In india most of the companys are making only compound chocolates it some times give a soapy of flaver when exposed to air.

In my native place Kodaikanal peoples are keeping chocolates in open for months with out geting spoiled, here temprature is usualy below 16 degree celcius ,

Moisture and heat are bad news... both shorten shelf life and can affect taste and texture (as can too much cold + moisture... which is why you don't keep chocolate refrigerated). Cool and dry are the best conditions.