Now in its tenth year, American Craft Beer Week is under way. Sponsored by the Brewers Association, the week-long promotion is focused on special events hosted by breweries and purveyors that highlight the art and revival of independent brewing in America.

“Celebrated since 2006, ACBW provides craft beer fans across the U.S. the chance to support their local brewery and, allows breweries and beer businesses the opportunity to connect with beer lovers,” said the BA media release. “Tens of thousands of beer beginners, beer enthusiasts and beer geeks toast the week each year.”

This year’s ACBW runs from Monday through Sunday. Here’s a link from the BA on the United States of Craft.

Beer is an incredibly versatile beverage. Using only minimal ingredients familiar to the brewing and culinary arts, brewers are able to craft spectacularly varied beers that run the gamut of flavors and aromas.

Sometimes though, these few ingredients seem to make some brewers claustrophobic and they chafe under any cries for “purity” in beer. These 10 wacky brews throw the Reinheitsgebot and usual kitchen ingredients out the window and embrace some highly unorthodox approaches.

Here’s our top ten of the weirdest beers and their ingredients.

Precious – Do you enjoy drinking beer but worry about aging prematurely? Do you like your light lagers laced with anti-aging ingredients?

Well, you’ll love Precious, a beer that actually has collagen as an active ingredient. Yes, the most abundant protein in the human body now has a tasty way to be replenished.

This brew, first crafted in Hokkaido, Japan by Suntory Holdings Limited, is marketed heavily towards women, with one of its chauvinistic taglines making that blatantly obvious: “Guys can tell if a girl is taking collagen or not.”