I was tipped off (thanks, Emma!) to a cool post with 100 cool food science experiments that you can do in your kitchen at the Accredited Online Colleges blog. Most (if not all) of these use readily available materials to illustrate some basic science principles. They would be great for geeky cooks or anyone that wants to get kids interested in science.
They're taken from a variety of sources and provide quite a wide breadth of ease and level of serious science. Also included are a variety of DIY projects, like making your own yogurt, that illustrate some science principles but might also appeal to those of us who want to try to make home-made versions of things you'd normally buy at the grocery store.
They make me a little nostalgic, as I remember doing some basic kitchen science experiments as kid from Mr. Science experiments-for-kids type books.