Some vanilla extracts contain alcohol and other additives, said Lior Lev Sercarz, a spice expert and founder of La Bo??te spices and biscuits, who creates custom spice blends for chefs like Daniel Boulud and Eric Ripert. (His blends are also available to home cooks.) On the other hand, the scooped-out seeds, which are sometimes alluringly referred to as vanilla caviar, are completely unadulter