Kashrut -- the set of laws and traditions governing kosher foods in the Jewish faith -- does not require rabbis to bless food. However, rabbis and their representatives do inspect manufacturers and restaurants producing kosher food to guarantee their adherence to the rules.
Requirements
A blessing doesn't make food kosher. Instead, food must adhere to rules that prohibit pork, shellfish and the use of dairy products and meat in the same dish, among other restrictions. It must be prepared in a facility that has separate equipment for handling meat and dairy products.
Mashgiach
The misconception that rabbis have to bless food to make it kosher comes from the role of the mashgiach. Mashgiachs inspect restaurants and food manufacturers to make sure businesses comply with kashrut. They do not bless food. If a business fails inspection, it does not receive a certificate allowing it to market food as kosher.
Blessings
Observant Jews say blessings over food before eating. These prayers are similar to equivalent traditions in Christianity, Islam and other faiths. They do not in any way make foods kosher.
Tags: bless food, dairy products, food kosher