I attempted to make baked sweet potato chips today. I sliced them into little rounds, patted them dry, put them on a preheated baking sheet, salted them, and baked on each side for 10 minutes or so in a 425 degree oven. The edges crisped beautifully but little bubbles began to form on the potato, and the inside of it was not the crisp texture I craved. I have a feeling the slices were not thin enough and that is what caused the texture but what caused the bubbles? Any suggestions for a better, crisper, sweet potato chip?