Preheat oven to 350 F. Line cupcake pan with paper liners.
Beat egg whites until stiff peaks form.
In a separate bowl, cream butter and sugar.
Combine flour, baking powder and salt in another bowl. Combine bourbon and peach juice in a measuring cup or separate bowl.
Alternate adding the flour mixture and the bourbon mixture into the butter/sugar mix untill all ingredients are added.
Stir in the chopped peaches.
Fold in a third of the egg whites, and then the rest of the egg whites.
Scoop batter into cupcake liners and bake for 20 minutes.
Let cupcakes cool in pan for approximately 5 minutes, then remove from pan and let cool on a cooling rack.