The word "duff" is English slang for broken.
In the late 1990's the Lion Nathan Brewery in Australia produced a Duff Beer that was unrelated to the show. A legal action was brought upon them by 20th Century Fox forcing them to stop production of the beer, pull the remaining items and destroy it. It is considered a collectors item and you can still find a few on ebay.
Another Duff beer is brewed by Daleside Brewery, an independent brewery founded in 1988 in Harrogate, North Yorkshire , England. Daleside produces a variety of beers including "Duff" a 5% ABV Dark Ale. Duff is Gaelic for black or dark.
A "Duff" is a heavy pudding, usually made with suet and dried fruit and steamed or boiled in a cloth.
A gentlemen named Rodrigo Contreras has the "patent" on Duff in Mexico and is producing a Duff Beer with an identical label as the cartoon brew. The article in Spanish, and a translation.
"The Duff beer consumed the character Homer Simpsons at the Bar of Moe in the American cartoon series The Simpsons, comes with success from two weeks ago in the city of Guadalajara.
"I am a fan of the series, I know the beer and I thought that the most expensive is already done, which is advertising. The project began almost a year ago with the registration of the mark and that delayed nearly a year until the patent release, "said the businessman Rodrigo Contreras Diaz. The young 28-year-old, who only studied two semesters of the Bachelor of Marketing, claims to be the only one who had the registration Duff in Mexico and is now awaiting the approval of the patent in the United States.
To clarify the doubts on the authenticity of Duff beer, Contreras says that "the design of the bottle is exactly the same as that of the cartoon." His company began two weeks ago with the production of 200 cases with 24 bottles of beer each, at a cost to the consumer packaging by about one dollar. "The first box of beer was produced on 5 June, and two weeks ago I made an initial order of 200 boxes," he said. "In four days here I have requested 5,000 and 500 boxes are already committed to customers who know they have to wait because the factory that produces them is small," he said."
The Alamo Draft House here in Austin had a few bottles of Duff Beer available during "The Simpsons" movie premier. I was met with uncertain looks when I asked the bartender about it's origins, just that it was a limited thing and shrugged. The beers were only a dollar and I couldn't resist a chance to enjoy one of Homer's favorite beers for a Homer style price.
Brewery: Duff Brewery Springfield(Austin)?
Style: Ale?
Color: Amber/Brown
Somehow a full bottle escaped from the theater, it will be used for further inspection and tasting. Judging by the home brew style cap, slightly askew label and a small amount of sediment in the bottle, I am guessing this is a home brew made special for the movie release. If anybody has any information feel free to email me about it!