Kosher food is food that meets Jewish dietary laws, or kashrut, which comes from the Hebrew word for "fit" or "proper."
The task of keeping kosher is greatly simplified by widespread kashrut certification. Products that have been certified as kosher are labeled with a mark called a hekhsher (from the same Hebrew root as the word "kosher") that ordinarily identifies the rabbi or organization that certified the product. Approximately 3/4 of all prepackaged foods have some kind of kosher certification, and most major brands have reliable Orthodox certification.
The process of certification does not involve "blessing" the food; rather, it involves examining the ingredients used to make the food, examining the process by which the food is prepared, and periodically inspecting the processing facilities to make sure that kosher standards are maintained.
So what exactly is Kashrut?
Simply put, Kashrut deals with what foods may be eaten, what foods may be eaten together, and how those foods are to be prepared. All foods are divided into three categories: Dairy, Meat and Pareve.
* Dairy: Milk and milk derivatives are considered dairy and may not be mixed with meat products. No food item that is dairy in nature can be eaten at the same meal as meat is served, and vice versa. Meat and dairy products, especially those that are not packed or that are unsealed, should be separated on a constant basis to avoid mixing.
* Meat: Meat must come from a kosher animal, as outlined by Deuteronomy 14. An animal is kosher if it has split hooves and chews its cud: Cows, sheep, goats, etc. Certain birds, which are not birds of prey, are also kosher: Chickens, turkey, duck, geese etc. Special rules govern the entire processing of poultry. Making a kosher chicken, turkey or duck takes about three times as long as a non-kosher bird. Many steps are still performed by hand, with extra care, extra time. Specially trained rabbinical inspectors check every single bird for any signs of abnormalities or disease, often rejecting birds that have already passed required government inspections. This assures the consumer of getting a completely healthy bird, processed in accordance with the highest standards of cleanliness, purity and wholesomeness.
* Pareve (or Parve): Pareve foods are those which are neither milk nor meat. Eggs, fruits, and vegetables are pareve and may be eaten or cooked with either meat or dairy. Fish is pareve, but may not be eaten or cooked together with meat. Many condiments and sauces which are kosher and pareve contain anchovy paste, and thus cannot be used in a kosher poultry recipe.