The Chain Gang: McCafe Shamrock Shake

Company description: "Smooth and creamy mint-flavored shake topped with whipped cream and a cherry."

Chain: McDonald's.

Location: 942 Market St.

Calories: 530 (in a 12-ounce serving), 11 grams protein, 15 grams fat, 86 grams carbs, 160 milligrams sodium.

Order time: About a minute.

Price: $2.37, including tax.

Review: Three times we stood in line at the McDonald's in the Gallery, and three times we were told that the Shamrock Shake was unavailable because the machine they use to make it was broken. After the third try, we gave up and dashed through pouring rain to the McDonald's at 9th and Market. The atmosphere there was even drearier than at the Gallery, but at least it had what we were after - a pale-green shake with darker whorls of color that tasted every bit as good as the official product description. It's basically a traditional vanilla shake with mint extract, a little like a creme de menthe parfait, minus the alcohol. The whipped cream and maraschino cherry are optional. On a scale of one to 10, the Shamrock Shake is a 10. And that's no Blarney.

Summary: McDonald's introduced the Shamrock Shake at selected restaurants in 1970 but didn't take it nationwide until last year. Its annual arrival is timed to coincide with St. Patrick's Day on March 17. Get it while you can.