Using Dishwashers for Both Meat and Dairy

Why is there an issue with using a dishwasher for both milk and meat dishes (separately). Doesn't the water get hot enough during the cycle, and also doesn't any remnants that might remain fall under nosein ta'am lifgam? Can we run the dishwasher empty between types of dishes?

Shalom!

Thank you for your question.

It is our view that a dishwasher cannot be kashered. Using the same dishwasher for both meat and milk dishes, not to mention attempting to kosher it for use on Pesach, is very problematic. Some of the serious halachic issues include: food residue stuck in between the various components of the dishwasher, the question as to whether dish racks and other internal components of the dishwasher are kasherable at all, the status of the water in the washing cycle (“kli rishon, ” “irui,” etc.), the status of the dishwasher detergent, and more. So too, the water in most dishwashers does not reach the preferred 100 degrees Celsius / 212 degrees Fahrenheit needed for proper kashering.

As such, one should be sure to only acquire a new, never used, dishwasher and to designate it for one use alone, either for meat or for milk, and either for “during the year” or for Passover. One who moves into a new home that includes a dishwasher must be very careful to verify its status with the previous owner. One who only has one dishwasher should wash dishes of the other type by hand.

One who used a dishwasher for both meat and milk dishes at the same time, will potentially forbid all of one’s dishes rendering them all non-kosher.

So again, it is our opinion that a dishwasher cannot be kashered, and must be exclusively designated for a single type of use.

The Halachot relating to dishwashers are generally derived from the Shulchan Aruch, Yoreh Deah, 95.