Kashrut is a set of biblical dietary restrictions that allow only certain foods should be prepared and certain food should be separated. This law prohibits cooking the meat and fish together or serving them together on the same plate and similarly they also prohibit on eating meat and diary together. This is because it is considered unhealthy to the human beings. Therefore, this separation is not only restricted to cooking and serving but also on the usage of cooking utensils, eating plates, cleaning dishwashers, too.
Two sets utensils: In general, a kosher household should have at least two sets of utensils (pots, pans and dishes) – one for meat and the other one for diary. This is because it carries the status of food to the next food that going to be cooked or served. (utensils carries the “status” of food that cooked and also the eaten plates carries the status of food).
Example: If you cook chicken soup in a sauce pan and later if you use the same pan for warming the milk. Then status of flieshik is transmitted to the milk and the milchik status of the milk to pan. But as per the law, this is considered as a forbidden mixture.
Stove Tops and Sinks: Stove tops and sinks becomes non-kosher utensils – when you cook the meat and dairy, stove tops come in contact with them and similarly when cleaning the meat and dairy utensils in the same sink.
Therefore, it is advisable to use the separate spoon rests and trivets when placing them on the stove top and during the process of cleaning the utensils, use dishpans.
Dishwashers: Generally, a kosher household has two separate dishwashers – one for the meat and the other for the diary. This done because the contact of meat and diary might create a kosher problem.
And other restrictions: Use a separate towels and pot holders for the meat and dairy.