PHOTO BY KRISTY GRAVER

Don’t feel guilty about guzzling gallons of Shamrock Shakes this St. Patrick’s Day season.

Through March 23, participating Mickey D’s restaurants will donate 25 cents from every minty beverage sold to Ronald McDonald House Charities. My daughter, who dresses more like the Hamburglar, is happy to contribute my money to the cause.

Hal Rosen, a Connecticut McDonald’s owner-operator, created the iconic drink in 1967, which is around the same time his Pittsburgh counterpart, Michael James “Jim” Delligatti, invented the Big Mac.

The Shamrock Shake went nationwide in 1970. Within four years, the limited-time-only treat helped fund the first Ronald McDonald House in Philadelphia. There are now more than 260 RMHC chapters around the world that work to support families with ill or injured children.

By the ‘80s, Shamrock Shakes were so mainstream, Stephen King gave them a shout-out in his novella “Rita Hayworth and the Shawshank Redemption.” (Can you imagine doing 20-years-to-life in an Officer Big Mac Climb-In Jail?)

These days, most bars and restaurants offer their own take on the shake as a St. Patty’s Day drink special. At Maggie’s Farm Rum, the Clover Shake is a mix of vanilla-infused rum, vanilla ice cream, cocoa and mint. It’s available at the distillery’s Strip District and Upper St. Clair sites as a cocktail, in double-portion to-go cans and in 32-ounce takeout jugs that are guaranteed to make you dance a jig.

To celebrate the Shamrock Shake’s 55th anniversary, McDonald’s brought back its old mascot, Uncle O’Grimacey. The webstore dedicated to Grimace’s long-lost Irish relative has already sold out!

I remember when locating a Shamrock Shake was a challenge. Two decades ago, if you visited a McDonald’s in March, there was a slight chance you might see it on the menu in tiny, green letters. Now there’s an electronic billboard near my house that advertises it every 10 seconds.

I’m happy the iconic dessert and the Ronald McDonald House are getting the recognition they deserve, but I will always miss the thrill of the hunt. Having to search for the elusive green sludge was part of its charm.

A Shamrock Shake tasted better when finding one required a wee bit o’ luck.