In Lonergan’s Bar, in Cashel, Ireland, my mother looked at me apprehensively as she raised a half-pint of ruby black stout.

“Will I like this?”

“It’s good for you,” the proprietor suggested, quoting the legendary advertisements that still beckon people off the streets and into Irish pubs.

So my mother took her first sip of Guinness in a bar with our name over the door. But the taps at Lonergan’s Bar may soon run temporarily dry.

Over 2,000 workers in Guinness’s Ireland plants plan to strike this Thursday for an undetermined amount of time. The motivation for the strike is the impending closure of the plant in Dundalk, Co Louth; according to union leaders, the closure of one of the company’s oldest plants will leave 147 people without jobs. If production halts, the supplies of stout and other brews made by the company are expected to run out by the end of April.

Familiarly known as the black stuff, kegs of Guinness stout share space under the bar with Smithwick’s, Harp, Carlsberg and Budweiser. Over the years, it’s been rationed to pregnant women, offered to blood donors and likened to mothers’ milk. For me, it was the first alcoholic drink with any appeal. Dark as chocolate with a creamy head and a bitter, coffee-like taste... It was love from first sip.

Across the Atlantic, I found many that shared my affinity. In Ireland, I learned that there is an art to ordering, to pouring, to drinking, to counting the rings of foam on the inside of the glass. Guinness isn’t just a beer any more than Harvard is just a university; it has become a cultural icon. On any given night, in any given pub with any given selection of brews, more than half the people over 18 had a pint of the black stuff in front of them and foam on their upper lip.

If the labor strike goes long enough, the face of the Irish pub could be totally transformed. Sales of stout in Ireland have dropped slightly in the last year (according to U.S. News and World Report), a change that could be attributed to a growing population of successful young adults who scorn the old-school brew. In the pubs I visited during my trip there, the glasses of younger people did have a noticeably lighter hue, and the popularity of Budweiser in this legendary land of ale made me shudder.

A stoppage of Guinness, however temporary, could hasten this decline. Last month, Coors Brewing Company hired a former Guinness marketer to gain a better foothold in the United Kingdom, apparently unaware that it’s impossible to order a glass of the pale stuff with a straight face. But if the Guinness actually runs out (or goes up in price, a possible result of importing it), watery American brews may have a chance to get hold of the market. A Coors Light, Bud Draft or even a creamy Cafrey’s Ale is a weak substitute for an Irish stout, but soon pintmen and pintwomen may not have a choice.

Irish pubs are not completely without hope; Guinness could be shipped in from England or any of the other 49 countries that produce it, including Nigeria and El Salvador. But despite the earnest statement on the company’s website that “These days everything about an Irish and a G.B. pint of Guinness draught are the same,” few of the faithful truly believe it. There’s something in the water from the Wicklow mountains, the Irish-grown barley or the Kilkenny hops.

Of recent strike actions in Ireland (including teachers and Aer Lingus employees), this one is gaining the most international attention. Seven months of talks between trade unions and plant owners have been fruitless, and suddenly a local plant closing is not the only thing at stake in this conversation. Guinness and Ireland are inextricably linked, and the idea of pubs without homegrown stout could mean a serious blow to national identity.

The effects of the strike—and how long it lasts—remain to be seen. But hopefully, by the time we visit Lonergan’s Bar again the strike will be settled, 147 people in Co Louth will still have jobs and stout will be flowing from the taps. Guinness that is brewed, poured and served in the nation of its birth is a unique nectar, and my mother deserves at least one more half-pint.