A Shamrock Shake -- or technically "Shamrock Triple Thick Milkshake" -- is a special product sold at McDonald's exclusively around Saint Patrick's Day. It is a standard Triple Thick Milkshake made with mint extract and dyed green.
According to a web site calling itself "Planet Shamrock," availability of the Shamrock Shake has varied wildly depending on locale. Although McDonald's corporate web site makes no mention of the item and no press releases have been issued regarding it, some cities like Pittsburgh and Boston have enjoyed annual Shamrock Shakes without interruption. Others have been without Shamrock Shakes for more than a decade. Apparently the choice is made by each franchisee; the home office does not mandate that every store carry them.
Here's a recipe for two Shamrock Shakes courtesy of foodgeeks:
- Ingredients
- 2 cups vanilla ice cream
- 1¼ cups milk, 2% lowfat
- ¼ tsp. mint extract
- 8 drops green food coloring
- Directions
- Combine all ingredients in a blender and blend on high speed until smooth. Stop blender to stir with a spoon if necessary to help blend ice cream. Pour into 12-ounce cups and serve each with a straw.
Sources:
http://foodgeeks.com/recipes/recipe.phtml?recipe_id=6368
http://www.tiktok.org/shamrock/