But Of Course You Have OUR Blessings...
There is a mistaken belief that certified kosher food is food that has been blessed by a rabbi.
In actuality kosher means that the food and all included ingredients conform to the body of law that deals with the processing and preparation of food that can be eaten by Jewish people. A rabbi does not bless the food though they often oversee the food production to ensure it falls within the category of kosher.
Just because a product is certified Kosher doesn't mean that it has been blessed by a rabbi. (With the exception of a blessing prior to slaughter, see below.)
The types of food
There are types of food that are strictly forbidden for consumption. It is important to know what these foods are as even minimal contact with the forbidden foods or their by-products during processing and preparation will result in allowable food becoming ineligible to be certified kosher.
Land animals can only be eaten if they chew their cud and have hoofs that are split in two. Allowable animals include cows and deer while pigs and rabbits are some animals not allowed as they do not meet both criteria.
Sea animals can only be eaten if they have fins and scales. This eliminates foods such as crab, shrimp and other shellfish.
Milk, eggs and other by-products of the restricted animals are included on the forbidden foods list.
Meat can only be certified kosher if Jewish law is adhered to during slaughter. As slaughter is a positive commandment of the Torah, a blessing is said by the Shochet before the animal is killed quickly and in the most humane way possible, with a quick stoke across the throat. Natural causes, or killing by another animal cannot be the cause of death. The animal must also have been healthy prior to slaughter. In fact, "Glatt Kosher" means the animal was carefully inspected AFTER slaughter to assure it had no disease (in this case, the lungs.)
Processing and preparation
In addition to being humane, a slash across the throat helps drain the blood in the quickest and most complete way. Meat from land animals must be devoid of all blood to be certified kosher. Any blood that remains in the meat after slaughter is removed through broiling, salting or soaking.
These meat products cannot come into contact with foods that are forbidden or with fish or dairy products even if they are kosher as well. This is in accordance with the prohibition of pairing meat with dairy or meat with fish and also extends to the utensils and food preparation surfaces used.