Of all the nerdy DIY gadgets we have at home, our oat roller might just be the family favorite. It's so user-friendly and fast, and the kids are big fans of oatmeal, granola bars, cookies, various baked goods, and muesli-- all of which taste so much better with fresh-rolled oats. Oat groats (or oat berries) are the whole-grain kernels which can be stored for up to twenty years and still stay alive and "fresh." But the minute you split, cut, or roll oats, they begin to oxidize and go rancid. All the germ and good oil that's been sealed inside the husk becomes quite unstable when exposed to air. That's why rolled oats from the store shelf taste different than oats that have just been rolled or cut. That said, muesli can still be delicious with store-bought rolled oats. And no matter how you come by your oats, homemade muesli is a much better value, far more customizable and nutritious than most store-bought breakfast cereal. The flavor combinations are endless; there's a muesli for everyone. It's a well-kept secret we're letting out of the bag because it's simply too fast, easy, and scrumptious not to try.