One of the coolest things about beer is how widely varied the stuff can be. A light and spicy saison is miles apart from a massively boozy barrel-aged imperial stout. There are intensely hopped IPAs, pumpkin ales, smoked pilsners, grapefruit hefewizens, and enough other styles to make your head spin.

And then there's sour beer, which is so weird that you might not even recognize it as beer at all. There are plenty of different sub-types — geuze, kriek, lambic, gose, and a bunch more — but what they all have in common is wild yeast or bacteria, which give off a tart, funky, and acidic flavor.

Back in the day, that was just byproduct of brewing without all of the sanitary safeguards that are in place with today. Now, breweries can carefully add this or that strain to sour their beer in a controlled environment, though it's still much trickier that your standard brew, and having that bacteria in the brewhouse risks infecting other non-sour batches.

But some of the old school Eurpoean originators of sour beer still do things the traditional way, giving each batch its impossible-to-perfectly-replicate flavor with natural yeast & bacteria that comes from the local air and centuries-old oak aging vats.

Those wild ingredients, plus plenty of aging time to let 'em work their magic, creates sour beer that's entirely different from your standard lager or pale ale — and it's well worth trying.

The Bruery Hottenroth

Berliner weisse

Berliner weisse is a low alcohol wheat ale that dates way, way back to 16th century Germany. You don't see it too often nowadays, but back in the 1800s it was hugely popular — 700 breweries made the stuff, and it held the title of most popular drink in Berlin. It was traditionally mixed with raspberry or woodruff syrup to add a sweet counterpoint to the beer's tartness.

Just a hundred years later, though, all but two of those breweries either closed or stopped making it, and the style nearly went extinct.

The Bruery's modern day take on the style is pale, refreshing, and only lightly tart, which makes it a great introduction to sour beer if you're on the fence. The 3.1% ABV and wheat base make it a great refresher on hot summer days, and it's not too pricey (about ten bucks for a 750ml bottle in our neck of the woods) compared to most sour beers.

Rodenbach

Flanders red ale

Rodenbach knows a thing or two about tradition. The brewery was founded in 1821 in Roeselare, Belgium, and they're still cranking out this signature brew that practically defines the style of Flanders red ale.

The brewers make a single base beer, then age part of the batch for up to three years in giant oak vats that are nearly 200 years old. The brewery then blends 25% of this super tart and funky aged beer with 75% fresh beer to get their flagship brew. The resulting beer bursts with interesting flavor -- rich dark fruit, tart candy-like sourness, and an earthy aspect that's not dissimilar to a good red wine.

If you're going to try one sour beer, let it be this one. It's a world-class example of a rare and interesting style from a centuries-old operation, and though some adventurous breweries have created their own takes on the style, this is the true benchmark. It's not all that difficult to find, either.

And if you want to try it with the flavors dialed up even further, pick up a bottle of Rodenbach Grand Cru and try it side by side the regular version. Grand Cru is the same stuff, but in different proportions — it uses 67% aged beer and 33% fresh.

Cantillon Kriek 100% Lambic

Kriek

Cantillon is another legendary Belgian brewery, and maybe the most revered. Their super funky sour ales have been brewed and aged at their small, family-owned facility in Brussels since 1900 with some of the brewery's original, 100+ year old equipment, and stateside appearances of their kegs and bottles are extremely coveted.

Rather than using carefully controlled brewer's yeast and sterile environments, Cantillon's brews are fermented spontaneously with wild yeast and bacteria from the surrounding Zenne valley. So like Rodenbach and their heirloom oak, the beers impossible to replicate anywhere else.

They exclusively make lambic beers, which has a few different sub-types. This specific kind, Kriek, is fermented with sour cherries to add a puckering fruit note to the tart, dry flavor.

Russian River Beatification

American Wild Ale

Russian River — makers of the cult favorite Pliny the Elder IPA — has a reputation for brewing some of America's best sour ales. This one, Beatification, is classified as an "American wild ale," which is a broad style of sour or funky beers that don't quite fit any of the old school European molds.

It's 100% spontaneously fermented, meaning the brewers don't add any yeast at all. Instead, it gets put into a coolship (a broad, open vat that kind of looks like a giant kiddie pool) to pick up whatever wild yeast and souring bacteria happens to be floating around the brewhouse. After a day of that, it's transferred to oak wine barrels, where it sits for a few months to pick up a slight woodsy note and let the souring magic happen.

If you can get your hands on a bottle by staking out a spot at the brewery's annual release or taking to the black market of beer trading, this stuff will blow your taste buds away. It bursts with punchy sourness and lemon, green apple, and hay notes with a slight funk.

New Belgium Le Terroir

American Wild Ale

New Belgium is famous for their crowd-pleasing core beers, which you can find just about anywhere in the country. But their inventive Lips of Faith brews prove that they can make knockout versions of tricky, complexly flavored beer just as well as (or maybe even better than) any of the cult favorite breweries.

This one plays into the wine world's idea of "terroir," which affects sour beers just as much as it does a good merlot. In this case, it's imbued into New Belgium's wood vats, where the batches are aged for three years. That's a long time to wait for a single batch of beer, but the results are worth it.

The golden-colored ale that comes out is packed with ripe peach and an earthy wood flavor, plus a generous dose of fruity Amarillo and Citra hops — an interesting addition, since sour beers usually only have a minimal amount of bitterness.

The Bruery Oude Tart

Flanders Red Ale

The Bruery's take on a Flanders red is a bit different than Rodenbach, but every bit as delicious. True to the style, batches age in oak barrels for anywhere from 6 to 18 months, and then get carefully blended together until the beer is just right.

Think of this one as Rodenbach on steroids, with similar earthy, toasty oak notes and a dialed-up sourness that hits your tongue like a ton of bricks. Underneath the tartness, there are layers of cherry and cranberry sweetness and leathery funk that all adds up to a beautifully complex brew.

Evil Twin Sour Bikini

American Wild Ale

This one's a bit unique. Rather than sticking to a classic style, Evil Twin takes their low ABV pale ale, Bikini Beer, and reimagines it as a sour. They call it a "sour pale ale," though since that's not an officially recognized style, it gets lumped into the "American wild ale" category.

In any case, it's a simple, light, and super tart offering that packs an intense lemon-y sourness. It won't win any awards for complexity, but it is refreshing, tasty, and wont' leave you dizzy if you drink two of them.