No, you don't need to peel your apples for this recipe. Keeping the skin on the apples during the juicing process can actually boost the nutritional content of your homemade apple soda, as a lot of the apple's fiber and antioxidants are located in the skin. However, if you're not a fan of the slightly more tart flavor the peel imparts, or if you're using non-organic apples (which may have pesticide residues on the skin), then peeling your apples is perfectly fine. It's all about personal preference and what you're comfortable with.