Require Immersion in a Kosher Mikvah
- Any vessel used in food preparation that was acquired from a non-Jew.
- If there is any doubt whether it was acquired from a non-Jew or from a Jew, it should be immersed without a blessing.
- If it was acquired from a Jew and you know it was not immersed, then it also needs immersion with a blessing.
What kind of utensils need immersion?
Any utensil that comes in contact with the food during its processing or its presentation, whether hot or cold, no matter how large or small in size.
What materials are the utensils made of?
- Any type of metal, including aluminum, and glass. These two types of utensils need immersion even if they are covered, i.e., with Teflon.
- Corningware and Corelle are immersed without a blessing.
What items do not need immersion:
- Plastic (Melmac, Nylon)
- Disposable Utensils — if used for a short time — like aluminum foil pans
- Glazed china, according to Rav Moshe Feinstein.