When the waiter at Mamma Mia informed me they wouldn't be able to make me a mojito because they were out of mint, I told him to just throw something together that was "sawayaka" (refreshing). A few minutes later, he returned with a drink called a Boston Cooler.

"What's in it," I asked.

The waiter screwed his head and sucked air through his teeth. "Shall I ask . . ."

"Don't worry about it," I replied, reaching for my iPhone. A quick search of Boston Cooler cocktail came up with mixed results. 

The Gourmet Underground Detroit site claimed the Boston Cooler was, one, not a cocktail, and, two, a Detroit City original:

"In the city where Fred Sanders is credited with inventing the ice cream soda, pharmacist and founder of America’s oldest soft drink, James Vernor, took it one step further with the Boston Cooler. Originally a mixture of sweet cream and spicy, tickle-your-nose Vernor’s ginger soda, the drink eventually morphed into a thick, vanilla ice cream-based blended shake that is still available at Detroit-area Dairy Queens and independent ice cream parlors."

Interesting as that may be, it had nothing to do with the tangy, light cocktail sweating on the table before me. Although I couldn't find any English language pages with information on the background of the drink, I did find a number of Japanese-language sites which did.

The Boston Cooler, I learned, is one of many so-called "city cocktails". Others include, the Frisco (which was featured on Rachel Maddow a few weeks ago, the Manhattan, and so on. Recipes for the Boston Cooler vary, but most call for the following:

2 oz of white rum

1 oz of fresh lemon juice

1 tsp of sugar. (Some recipes recommend powdered sugar,

    the Japanese ones I found call for syrup)

3-4 oz of soda water or ginger ale

One recipes suggest pouring the rum and lemon juice into a tall glass (collins glass) first, then stirring in sugar, adding ice and filling glass with soda water or ginger ale. This reminds me of the slipshod way drinks are mixed by many "mixologists" in the U.S.

A more promising recipe says you should add lemon juice, sugar and 2 oz of club soda together in a collins glass, fill the glass with cracked ice, add rum, then top with club soda, and stir. "Garnish with a spiral of orange or lemon peel, and serve." (By all means, do not forget to serve!)

A more thorough recipe found in the Japanese Cocktail Recipe 1000 recommends pouring the rum, freshly squeezed lemon juice, syrup in a shaker. After shaking it, pour it into a "zombie glass" (or a similarly large glass) that has ice in it. When it has cooled, top off with ginger ale (or soda water if there is no ginger ale) and stir gently. Garnish.

To be honest, I would have preferred drinking a mohito, but the Boston Cooler was a pretty good substitute on that hot day.