Changing its recipe probably won’t attract new drinkers, but it will put off stout fans Guinness dates back 256 years and is laden with deep cultural connotations for both the Irish and Irish diaspora here in the United States. Any significant change to it is risky. Even if it means removing an element deemed repugnant by a large segment of the population. We could be talking about isinglass — the clear collagen extracted from fish bladders that is used to draw spent yeast out of beer and clarify the finished product — but Guinness is planning to remove that particular substance from its brewing process in 2016 in favor of another less-fishy filtration method. There wasn’t all that much left in the beer once it finished brewing anyway, but that wasn’t enough to keep folks from petitioning to get those decidedly non-veggie/vegan fish bits out of Guinness altogether. Or we could be talking about the “” of Guinness mythology: Dead rats supposedly found during a cleaning of the Guinness holding tanks that allegedly contributed to the beer’s flavor. That story is regularly disproven as a myth, but it does speak to the cult of personality built around Guinness. From the six-step, 119.5-second “surge and settle” pour off Guinness’ nitrogen-powered taps — no, you don’t have to do it that way, but it helps if you like that nice head — to the flavor of Guinness in Ireland compared to the U.S.,Guinness just teems with superstition and folklore.While Great Britain and Ireland have always consumed more Guinness than the U.S., Nigeria now joins them above the U.S. in the ranks of consumers. Which is what makes a seemingly inclusive switch to a new filtering process so dicey for Guinness. Already, irate Irish and U.S. drinkers have drawn up a petition of their own to keep isinglass part of the Guinness brewing process. Granted, it’s led by “CBS Late Show” host Stephen Colbert — with U.S. Guinness playing along — but it brings up a valid point: Why is Guinness so quick to offend loyal drinkers by “changing the recipe” (isinglass isn’t an ingredient) in an effort to draw drinkers who weren’t considering a pint anyway? Because, frankly, it has little choice. In the U.S., Diageo-Guinness sales dropped from 3.3 million barrels in 2006 to roughly 2.4 million in 2014. Its U.S. sales have fallen steadily since 2010, while Diageo’s global sales have hit a two-year slump. While Great Britain and Ireland have always consumed more Guinness than the United States, Nigeria now joins them above the U.S. in the ranks of Guinness consumers, with stout-loving Cameroon and Kenya following closely behind. In an effort to spur sales and compete with craft beer here, Guinness has experimented with Blonde American Lager, Black Lager and Nitro IPA. Even in Ireland, however, Guinness has watched craft beer grow 50% within the past year and 180% since 2011, according to Euromonitor. Not only that, but beer consumption in Ireland overall decreased 14% last year thanks to beer taxes and concerns about health. Guinness still has a dominant 19% share of the Irish market, but that’s down from 26.6% in 2011 and 31% a decade ago. Meanwhile, Irish interest in stout has declined significantly since the 1970s, when the Irish Competition Authority says the beer style accounted for 70% of all beer consumed. Today, that share is less than 30% as light lager from Budweiser, Heineken, Carlsberg, Corona and Tuborg take hold. Even in the style-friendly U.S. craft beer market, stout accounts for only 2% of all supermarket craft beer sales and just 3% of all bar and restaurant pours, according to IRI. That isn’t great news for Guinness, which already has a tough time convincing skeptics that U.S. Guinness is just as good as that in Ireland. (Even food experts argue it isn’t.) Combine that with the misconception that a dark Guinness stout is a heavy beer — its 125 calories per 12 ounces is less than the 145 you’ll find in a Budweiser — and Guinness will take just about any new drinkers it can get. However, vegans and vegetarians aren’t exactly short on beer options. If getting them to try one pint costs Guinness loyal drinkers who already have multiple pints in a sitting, it isn’t going to take very long for Guinness’ surge in visibility to settle. Jason Notte is a freelance writer based in Portland, Ore. His writing has appeared in The New York Times, The Huffington Post and Esquire. Notte received a bachelor’s degree in journalism from the S.I. Newhouse School of Public Communications at Syracuse University in 1998. Follow him on Twitter https://twitter.com/Notteham!function(d,s,id){var js,fjs=d.getElementsByTagName(s)[0],p=/^http:/.test(d.location)?'http':'https';if(!d.getElementById(id)){js=d.createElement(s);js.id=id;js.src=p+"://platform.twitter.com/widgets.js";fjs.parentNode.insertBefore(js,fjs);}}(document,"script","twitter-wjs");. More from MarketWatch