From a kashrut point of view, a modern dishwasher is by far the most complicated appliance in the kitchen. What goes on inside is the following:
- Some amount of hot water is sprayed around on the dishes inside.
- At some point, soap is released, typically from a compartment in the door. This soap gradually mixes in with the spraying water.
- In some dishwashers, a heating element heats the water inside to a high temperature, possibly even yad soledet bo.
If the dishwasher heats water to yad soledet bo, then the dishwasher is acting like an oven and is "cooking" the dishes inside.
Ashkenazic Jews therefore restrict use of the dishwasher to either meat or dairy dishes. Sephardic Jews are generally more lenient with dishwasher use. Some Sephardic rabbis allow the use of one dishwasher for both meat and dairy dishes even at the same time provided that:
- The dishes are rinsed clean of all foodstuff before being placed into the dishwasher.
- Soap is placed not only in the soap compartment but also in the main compartment of the dishwasher. This way there is never water in the dishwasher without soap.
- The dishes are placed such that meat and dairy dishes cannot touch each other, typically by using separate racks.
At any rate, Sephardic Jews can certainly use the same dishwasher for meat and dairy during separate cycles, especially if they adhere to the above procedures. Check with your rabbi to see what is acceptable in your community.
Ashkenazim will not allow the dishwasher to be used in this manner l'chatchila, though b'dieved Ashkenazim will agree that accidental simultaneous use of the dishwasher for milk and meat dishes does not render anything non-kosher.
Questions to ponder:
- How do I kasher my dishwasher?
- What if I accidentally put milk and meat dishes in the dishwasher together?
- Can an Ashkenazic Jew eat in a Sefardic Jew's home and vice versa?
- Rabbi Mansour (a prominent rabbi in the Brooklyn Syrian community) on dishwashers
- Chacham Ovadia Yosef, Yabia Omer, Chelek Aleph