As a child I remember Mother making Shirley Temples for us girls. Should a boy happen to be visiting she would say his was called a Roy Rogers (though I do believe that really is a different drink). I did the same for my children and they remember how much fun the drink was.
Heat the 4 cups of cherry juice over moderate heat until it begins to simmer. Continue simmering until the juice is reduced by half. (This step took about an hour. But basically you just “set it and forget it”).
Remove from heat and add two cups of sugar, stir until dissolved and then let cool completely.
Recipe makes about 3 cups of syrup. Leftover syrup can be stored in the fridge up to a month.
To “mix” your Shirley Temple….fill a glass with ice and then add 2/3 sparkling water, and 1/3 third grenadine (more or less to taste)and garnish with citrus slices and maraschino cherries.
Now should you be short on time you could just buy your Grenadine...:)