Kirsch liqueur, also known as kirschwasser, is a cherry-flavored brandy that's used in fondue and desserts like cherries jubilee. If you can't find kirsch or you'd rather skip the alcohol, there are alternatives, but they're not always perfect substitutes. For example, kirsch is used in fondue because the alcohol smooths the melting of the cheese.
Syrup or Juice
For recipes in which alcohol isn't required for a chemical reaction, replace kirsch with an equal amount of black cherry, raspberry or boysenberry juice or syrup. Either use the liquid from canned berries or pick up some berry-flavored Italian soda syrup.
Framboise or Cherry Liqueur
Substitute with equal parts framboise (a French raspberry brandy) or cherry liqueur. Use framboise if the recipe calls for a brandy flavor, or opt for cherry liqueur for more cherry flavor.
Cherry Preserves
Cherry preserves won't work in fondue recipes, but they're great in baked goods. If desired, thin the preserves with boiling water first to more closely replicate the consistency of the kirsch liqueur.