On September 29, 2011, after the first night of the annual Great American Beer Festival in Denver, Left Hand Brewing publicly revealed a bottled beer that its owners and brewers had spent two years and hundreds of thousands of dollars to create.

See also: - Strange Brewing faces a trademark threat from a Massachusetts homebrew shop - Left Hand's fresh-hopped Warrior IPA tastes fresh off the plane - Left Hand Brewing becomes the first U.S. craft brewer to bottle a nitro beer

With Milk Stout Nitro, the Longmont company became the first craft brewer in the nation to gas one of its beers with a blend of carbon dioxide and nitrogen. As a result, the rich stout pours creamy and thick out of the bottle, with bubbles that cascade up from the bottom, just like it would if it were being drawn from a nitrogen-infused tap at a bar.

Left Hand had been fiercely secretive about Nitro beforehand, so much so that it didn't even file for a patent of its process, fearing that the beer could then be copied. The brewery did, however, apply for a trademark on the words "Milk Stout Nitro," hoping, like any good business, that it could protect the name of its invention.

But the U.S. Patent and Trademark Office denied Left Hand's application that November, saying the term "Nitro" -- as it applies to beer -- had already been protected more than a decade earlier by a man named Eli Gershkovitch, who owns Vancouver, Canada's Steamworks Brewery (no relation to Steamworks Brewing in Durango).

The news was a blow to Left Hand, which was expanding rapidly, led now by Milk Stout Nitro, which quickly became a top-seller. Even worse, Gershkovitch and Steamworks didn't appear from its website to be making a beer with the word "nitro" in it, either in Canada or in the U.S. -- something it needed to do in order to protect the mark.

So, after doing some research, Left Hand decided to challenge Gershkovitch's claim to the word, and last July, it filed a petition to cancel his trademark.

Even more dramatically, Left Hand accused Gershkovitch of having outright lied to the government about its use of the word "nitro," insisting that he had never used the mark and that its registration "was obtained fraudulently."

Gershkovitch -- who is currently involved in another trademark dispute over the word "Cascadia" -- has denied all of the allegations and asserted in documents that he "has continuously used the 'Nitro' mark in commerce since November 30, 2004.

Left Hand co-owner and co-founder Eric Wallace declined to discuss the case, saying it is ongoing and will continue to be for some time. A trademark office filing lists scheduled court dates related to the case all the way through October 2013.

But Wallace acknowledges that trademark issues are becoming more prevalent for craft brewers in Colorado and around the country. "We are certainly not alone in dealing with this," Wallace says. "The industry in general is seeing quite a bit of it now."

Wallace also points out that obtaining trademarks is one thing, but that it's also important to defend them in order to keep them in effect.

Founded in 1993 by Wallace and Dick Doore, Left Hand is no "stranger" to naming issues. Originally called Indian Peaks, Wallace and Doore turned to the Left Hand name after realizing that another Colorado beer maker, Boulder's Walnut Brewery, made -- and still makes -- Indian Peaks Pale Ale. Left Hand is still incorporated under the Indian Peaks moniker, however, even though it doesn't do business under that name.

More recently, Left Hand itself asked Eagle's Bonfire Brewing last summer to change the name of its Strange Blonde Ale because Left Hand was producing a pale ale called The Stranger, which it had filed a trademark on in August 2011.

And Left Hand is far from the only Colorado brewery that has had to hire a lawyer to handle trademark disputes. Oskar Blues, Upslope and Del Norte (which just closed) have all done so. Great Divide currently faces potential opposition to its Wolfgang dopplebock from the Wolfgang Puck restaurant empire, while New Belgium is fending off the Texas Rangers baseball team over the use of the word Ranger for its IPA.

Numerous other breweries have fielded phone calls, strongly-worded requests and cease-and-desist letters over similar issues. Denver's Strange Brewing, for instance, is currently waging a war of words with a similarly named Massachusetts homebrew store.

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