Cold brew coffee is a hot trend

This season’s hottest coffee trend is cold brew. In fact, sales of the beverage went up almost 339 percent between 2010 and 2015.

So we're investigating what goes into making this delicious and caffeinated drink.

So what is cold brew?

The process starts with ground beans placed in a filter that is then soaked over night in a bucket of cold water.  At no point is heat ever used.

With cold brew becoming more and more in demand, it's starting to pop up everywhere with Starbucks launching its cold brew offering in thousands of stores early last year.

And even Dunkin' Donuts is getting in on the trend.  Just last month the chain, which is reportedly the number one iced coffee retailer in the country, jumped into the cold brew game, taking the specialty beverage one more step from niche to mainstream.