How to Make It
Process berries in a food processor until completely smooth, about 20 seconds; set aside.
Bring 2 cups water and the sugar to a boil in a saucepan over medium-high, stirring occasionally. Stir in blueberry puree; reduce heat to medium. Simmer 2 minutes. Pour through a fine mesh strainer into a bowl, pressing lightly. Discard solids. Stir lemon juice into strained mixture. Cool completely, 30 minutes.
Pour mixture into an 8-inch square pan; cover tightly with aluminum foil. Freeze until completely frozen, 12 hours or up to 24 hours.
Break mixture into pieces using a spoon, and transfer about one-fourth of pieces to a food processor. Process until smooth but still frozen, about 1 minute; transfer to a container or serving bowl. Repeat until all pieces have been processed. Serve immediately, or cover and freeze until ready to serve.
Omit Steps 1 and 2 in the Blueberry Snowballs recipe. Bring 2 1/4 cups water and 1 1/4 cups granulated sugar to a simmer in a small saucepan over medium-high, stirring occasionally until sugar dissolves. Remove from heat, and stir in 1 tsp. fresh lime zest and 3/4 cup fresh lime juice (from 6 limes). Cool sugar-lime mixture completely, about 30 minutes. Proceed with Steps 3 and 4 as directed.
Omit Steps 1 and 2 in the Blueberry Snowballs recipe. Bring 1 cup granulated sugar and 1/2 cup water to a boil in a small saucepan over medium-high, stirring occasionally, until sugar is dissolved. Chill sugar mixture 30 minutes. Process
5 cups seedless watermelon cubes and the chilled sugar mixture in a blender or food processor until completely smooth, about 1 minute. Pour mixture through a fine mesh strainer into a bowl, pressing lightly. Discard solids, and stir 3 tablespoons fresh lime juice (from 2 limes) into strained mixture. Proceed with Steps 3 and 4 as directed.