When the folks at Universal Orlando decided to bring Homer Simpson's favorite beverage, Duff Beer, to life in its new Springfield attraction, they knew just whom to call: the man who invented Butterbeer.Executive chef Steven Jayson led the team that created the signature drink of the Wizarding World of Harry Potter at Universal's Islands of Adventure. "I flew to Scotland and met J.K. Rowling, presented her with Butterbeer and got her to approve it," he said. "And now here we are almost three years later, and well over 7 million Butterbeers have been consumed, and it's the talk of the Wizarding World of Harry Potter."Going from Butterbeer to actual beer was a natural next step — especially a beer as iconic as Duff. When Springfield opens in full this summer, the heretofore fictional brand will be everywhere. It's already on tap at Moe's Tavern, which opened a few weeks ago, and a taproom-style Duff Brewery will open soon. The gift shop is full of Duff-themed items, from mugs, buckets and apparel to cans of a Duff energy drink. Soon, there'll be a giant statue of Duffman and topiaries of the Seven Duffs, characters in The Simpsons' fictional Duff Gardens.Unofficially, Duff has existed for years, thanks to cheeky, copyright-skirting brewers around the world. But this is the first version sanctioned by The Simpsons. Reportedly brewed by Melbourne's Florida Brewing Co. — Universal honchos won't say for sure — it's available in three variations: Duff, Duff Lite and Duff Dry. (Sorry, fans, you'll have to wait for Duff Blue, Duff Extra Cold and Henry K. Duff's Private Reserve.)Park officials are calling it a "craft beer," which is technically true, but don't go in expecting bold, hoppy flavors or notes of vanilla or burnt caramel. Duff is light, malty and not particularly strong; reviewers have compared it to Yuengling, Keystone Light and Budweiser. Jayson said Universal experimented with about a dozen versions of Duff, even flying it out to California for a taste test with Simpsons creators Matt Groening and James L. Brooks and members of the show's writing staff. They also brought nonalcoholic drinks from the rest of the menu, including a cherry-flavored Buzz Cola and a green, punchlike Mount Swartzwelder's Apple Drink (on the show, "Mount Swartzwelder" was named for legendary Simpsons writer John Swartzwelder). And then there's the Flaming Moe, an orange concoction that smokes and bubbles with dry ice and tastes like Sunkist mixed with citrus Gatorade. On The Simpsons, Flaming Moes are purple, fiery and, it should go without saying, alcoholic. "We made a joint decision that the Flaming Moe was going to be a nonalcoholic drink so that everyone could enjoy it," said Universal Orlando senior vice president Ric Florell.Even so, Duff is bound to be the beverage of choice in Springfield, just as Butterbeer is the top draw one park over."It's the No. 1 thing that people want to do when they visit the Wizarding World of Harry Potter, is have a Butterbeer," Jayson said.