Combine water and sugar in a small saucepan. Bring to a boil; reduce heat, and simmer until all sugar has dissolved, about 2 minutes. Remove from heat.
Place pitted cherries and simple syrup (sugar mixture) in a blender, and process until smooth. Stir in Lambic; pour into a freezer safe container, cover and freeze for 8 hours or until firm.
Remove mixture from freezer; scrape with a fork until fluffy.