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17th Mar 2023

A history of the Shamrock Shake, the mint-flavoured tribute to St Patrick

By Fiona Frawley

Legend has it ’twas St. Patty’s beverage of choice during those long shifts banishing the snakes from Éire.

Like many aspects of the St. Patricks Day celebrations, the Shamrock Shake is a wholly American invention but has somehow become synonymous with festivities here in Ireland too.

I definitely remember seeing ads for the green-tinted drink as a child, and even once or twice enjoying one to accompany the rare treat of a Happy Meal on those blissful days the milkshake machine was working. The shakes were probably an easy sell for the Irish market as many mint-flavoured desserts tend to do well here – mint choc chip is the go to ice-cream flavour for many an Irish da, and there’s few of us can resist an aul Dairy Milk Mint Crisp when they’re staring up at us from their spot on the shop counter.

Sure, we could take this opportunity to investigate the story of St. Patrick himself, or the history of pagan holidays in Ireland but instead, we’re throwing all our eggs in the shamrock-shaped basket and embarking on a deep dive into this seasonal treat. It’s crucial work, tbh.

The history of the Shamrock Shake

The Shamrock Shake was first introduced by McDonald’s in 1970 but other reports say the drink was concocted by Hal Rosen, a Connecticut McDonald’s owner and operator in 1966. While its original origins are unclear, the shakes’ real phenomenon breakout came years later in 1975. According to a 2011 report by, “it all began with a little girl, a football team, and a visionary doctor.”

Reportedly, the idea for the shake came about after Philadelphia Eagles tight end Fred Hill’s daughter was diagnosed with leukemia and began treatment. The Hills camped out on hospital benches and in waiting rooms and saw other families doing the same, and wanted to do something to help.

As Fred and his teammates rallied to raise funds, Jim Murray, the team’s general manager, called a friend from McDonald’s advertising and suggested they team up during the next promotional push, which happened to be St. Patrick’s Day. They settled on the Shamrock Shake as a perfect vehicle for the cause. It was green, like the Eagles’ uniforms. Enough funds were raised to buy a four-storey house, which became the first Ronald McDonald House. From 1975 on, a portion of each Shamrock Shake sold went to the Ronald McDonald House Charity.

The shakes are available exclusively in the US, Canada and Ireland.

Uncle O’Grimacey

The Shamrock Shake increased in popularity after the introduction of Uncle O’Grimacey, McDonald’s character Grimace’s Irish relative. The shamrock-clad monster was deployed to promote the shakes – here’s an early ad featuring O’Grimacey, begorrrah-ing away:

The character has since been phased out, some might say for obvious reasons.

Ups and Downs

Throughout the 1990’s and early 2000’s, the Shamrock Shake disappeared in many US locations as the decision to carry the drink was put up for a vote to each region’s managers (New York State’s McDonald’s famously voted no for many years, according to Gluttoner.)

In the 2010’s the beverage began to make a resurgence, going national for the first time across the United States in 2012.

In 2010 McDonald’s created the World’s Largest Shamrock Shake in Chicago, to raise funds for the local Ronald McDonald House there. $10,000 was raised as a 24-foot shake was placed along the ‘green-for-St. Patty’s’ Chicago River.

In 2017 McDonald’s launched several variations on the shake, including the Shamrock Chocolate Shake, Shamrock Chocolate Chip Frappé, Shamrock Mocha, and Shamrock Hot Chocolate.

Today, the minty treat is available in McDonald’s branches across Ireland for a limited time only – will you be enjoying one this year?