Lambic is a style of beer whereby the wort is purposely left open to the environment for fermentation to occur spontaneously. Wild yeasts and bacteria ferments the beer giving lambic a complex and very distinct flavour that usually has a sour after taste.
TELEGRAPH : What on Earth is Lambic?
“Lambic is not just the oldest beer style in the western world, it’s the weirdest. It’s been brewed in and around an otherwise unremarkable corner of Brussels for more than five hundred years and it can’t be produced anywhere else (hundreds have tried but few have come close). What distinguishes lambic from your usual conventional contemporary beers is that it’s spontaneously fermented with naturally-occurring, local, airborne yeast specific to this particular part of the world, known as Payottenland, between October and April.”
NEW YORK TIMES: Lambics: Beers Gone Wild
“The brew ferments in barrels, like certain examples of that other fermented beverage, and evolves into a dry, almost sour beer with a fresh, lively acidity and an appealing funkiness. As the brew ages, it mellows and takes on a rich, fruity complexity. One final point: It is a lot easier and far more affordable to taste the best beers in the world than the best wines.”
THE SPRUCE EATS: Lambic Beer Profile
“To the initiated lambics can be startling. The spontaneous fermentation creates a beer unlike any other in its sour, funky, and bright flavors. Beneath these in-your-face flavors lurk dusky, earthy notes that bring a complexity to the beer that keeps it interesting. Garrett Oliver describes lambic as a riot of flavors and we do not know of a better way to put it. Fruited lambics tend to be a bit less complex though no less enjoyable as the sour qualities of the beer support and enhance the flavors of the fruit or berries that were added to the fermentation tank.
As a companion to food, we find it helpful to think of lambic like champagne. Lambic without fruit is much like dry champagne while the fruited ones are a lot like sweet champagne. If that analogy fails for you try thinking of lambic as the ultimate palate cleanser, a sour sorbet. From this approach, it's easy to see that there are a few foods that cannot work with lambic. It can be particularly good with salads and sweets but it can be quite good with cream sauces or Indian food. If you like lambic you will like lambic with almost any food.”
THRILLIST: Why You Should Drink Lambics, One of Belgium’s Best and Wildest Beers
“Lambic beers are kind of renowned for their funkiness. They can be hay-like or cheesy or musty, cider-y,” Martin explains. “People use terms that sound off-putting, like barnyard… when you describe it, it doesn’t sound appealing. But it’s really complex and really unique.” That's what makes them more fun to drink than say a lager or and IPA -- you never totally quite know what you might get when you crack open a lambic.”