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.