The kashering of a dishwasher is very controversial. I suggest you check with your local rabbi to see what the appropriate halacha is for your community.
I hold that a dishwasher can be kashered, whether for Passover use, from milk to meat (or vice versa), or from non-kosher use; however, the ability to do so depends on the materials of which the inside of the dishwasher is made. A variety of scenerios are presented herein, but I must emphasize that you cannot read this page as halacha l'ma'aseh without working closely with your rabbi to see if the halacha herein is applicable to your situation.
If your dishwasher can be kashered, you can do so using a special hagala for dishwashers.
- Keeping kosher for the first time. If you are keeping kosher for the first time, the halacha of kashering your dishwasher is the most lenient. Rav Moshe Feinstein in his widely accepted takanat hashavim ruled that even china (kli cheres) can be kashered for someone in this situation. To kasher:
- Follow the procedure for hagala.
- If your dishwasher is made of porcelain on the inside, wait one year before using your dishwasher.
- At the end of the year, run the dishwasher once with soap prior to use.
- Kahsering for Passover, from non-kosher, from milk use to meat use or from meat use to milk use. A porcelain dishwasher cannot be kashered. A stainless steel dishwasher is kashered by hagala. If the inside of your dishwasher is made of some other material, check with your rabbi.
- Ashkenazic Jews must designate the dishwasher as dairy or meat and only use it for the appropriate dishes.
- For Sefardic Jews, the halacha is more lenient:
- Certainly the same dishwasher may be used for meat and dairy dishes, though not at the same time.
- Some Sefardic Jews even allow the dishwasher to be used for meat and dairy dishes at the same time provided that
- the dishes are rinsed of all foodstuff prior to loading into the dishwasher;
- the dishes are placed such that meat and dairy dishes do not touch;
- soap is thrown into the dishwasher cavity in addition to the soap container.
- These same leniencies may allow a Sefardic Jew to kasher even a porcelain dishwasher. Check with your rabbi.
- Shulchan Aruch Yoreh Deah 95:3-4
- Iggros Moshe Orach Chaim 3:58; Yoreh Deah 3:28 (dishwashers)
- Iggros Moshe Yoreh Deah 2:46 (takanat hashavim)
- Hagalas Keilim 13:225-228
Questions to ponder: