Interviewer: “So did you learn any drinking-related traditions while in Ireland?”
Informant: “Yes! Drinking was so much fun there. My favorite tradition that I learned is called drowning the shamrock.”
Interviewer: “What is that?”
Informant: “So you only get to do it once a year on St. Paddy’s Day and at the last call for the night. So basically, everyone orders a shot of whiskey at the bar and then together everyone puts the 4-leaf clover pin from their clothing in their shot and then shouts ‘To St. Patrick!’ and then takes the shot. Then the clover pin is thrown over your left shoulder”
Interviewer: “Why throw it over your left shoulder?”
Informant: “I have no idea. I think it’s like for good luck or something”
Informant is a 21-year old female USC student who comes from New York City. She was told this tradition while studying abroad in Ireland.
The idea behind drinking traditions has been around since the invention of alcohol, so it’s not surprising that the Irish have a drinking tradition to end St. Patrick’s Day. The idea of putting a lucky object into a drink and drinking it appears to express a want to be lucky and to have good fortune. The throwing of the clover over the left shoulder most likely symbolizes the start of a new beginning and the clover represents sending good fortunes to your future self.
See also the following link for another example of Drowning the Shamrock.