The most common reasons your apple crisp is dry and not juicy are that you used old apples, chose the wrong varieties, over-baked the crisp or you did not macerate the apples in the sugar first. Apples slowly lose their moisture over time which is why they shrivel up. Choose firm, bright looking apples that feel heavy for their size. Different varieties of apples will release more or less moisture. Choosing several will help beat the odds. Lastly, no matter the apples you choose, allowing the apples to sit in the sugar will start the process of pulling out the water content. They will continue to release moisture as they bake.