Rabbi Aharon Brun-Kestler loves the crusty baguettes from Essential Baking Company but that’s not why he or a member of his staff pays frequent visits to the Seattle artisanal bakery. Instead, he’s there to ensure that the products they sell as kosher stay kosher. Rabbi Brun-Kestler is the executive director of Seattle Va’ad, which supervises the koshering of products and restaurants and is part of a network of hundreds of similar organizations whose symbols appear on thousands of products.