Sour Beers were hot last year and they're only heating up. It's part of a larger trend that includes the rise of Greek yogurt, kimchee, and even coffee as Starbucks has capitalized on the increasing popularity of sour flavors with its new Unicorn Frappuccino. If you haven't tried any sour beers yet, this is probably the summer you will.

"Sour" is kind of a catchall for beers that are purposefully brewed to taste a little funny. They have a storied history but their revival has as much to do with their funkiness as with their past. But the reason you'll probably drink one is that they are becoming easier to get your hands on.

On the face of it, sour beers aren't like anything you would expect. They can be tangy, lemony, and even salty, but also refreshing in the same way lemonade is oddly quenching on a warm day. Beers are soured during the fermentation process for the explicit purpose of changing the flavor of what would taste like a normal beer into something exotic. And these beers are taking off. In fact, BrewDog's planned beer hotel even features a "Sour Room."

Part of their popularity is they're at the far end of the spectrum for craft beer lovers who are constantly looking for new and more challenging flavors. Having explored the far reaches of bitter beers with palate-shocking IPAs, new taste sensations are coming more into vogue than ever.

Seasonal sour beers make a splash

Sours are challenging to make, and in a world where an increasing number of craft brewers are trying to set themselves apart, sour beers offer a line of distinction that can't be replicated. Many sour beers also can be low in alcohol and high in flavor, making them a popular summer choice. They are good cold and can be drunk throughout the day.

2017 is the year for sour beers. Because they are so drinkable, and because the fruits that often flavor them come into season from early spring through summer, more breweries than ever have decided to produce their own sour beers and to begin distributing them.

In Dover, Del. Fordham and Dominion Brewing Co. have released The 11th Sour, a light, slightly grape-y Berliner Weisse that is deceptively refreshing.

There's no question that it's a beer, but the light purple color and the fruit flavors give it something of a wine character as well.

Canadian brewery Nickel Brook Brewing Co. will release a mixed six-pack of sour beers this year, which will act as a kind of tour for its new line of sour beers. The new beers include a cucumber-lime Gose, a dry-hopped Gose, and an American Pale Ale soured with Brettanomyces yeast. A Gose is a sour ale that tends to have lemon and herbal flavors, as well as a saltiness throughout.

The popularity of sour beers, along with the increase in breweries that are canning them, means more sour beer will be widely available as the summer months come. What this means is that even casual beer drinkers will have new words like Gose, Lambic, and Berliner Weisse enter their vocabulary. It's the next style of beer that everyone will have an opinion about.