Here is information from Star-K conerning Kashering utensils:
http://www.star-k.org/kashrus/kk-containers-tevilas.htm
The Mitzvah of Tevilas Keilim
Rabbi Moshe Heinemann, Star-K Rabbinic AdministratorIntroduction:
In His infinite wisdom Hashem Yisborach has spiritually elevated the mundane activity of eating and has vested it with special sanctity, special kedusha. The food we eat must be kosher; the table upon which we eat our meals represents the holy altar, the mizbeach. Similarly, the vessels and utensils used for preparing food and for dining must be given special holiness. When these dishes and/or utensils have been previously owned by a non-Jew we have to immerse these utensils, these keilim, in a mikvah, a ritualarium, before their first use.
Keilim (vessels/utensils) can be categorized into three halachic groupings. Utensils requiring tevila (immersion) with a brocha, utensils requiring tevila without a brocha, and utensils not requiring tevila at all. Utensils require tevila with a brocha when they have direct contact with food during preparation or meal time and are made from metal such as aluminum, brass, copper, gold, iron, lead, silver, steel, tin, or glass such as pyrex, duralex, and corelle. (Corelle, a form of glass, should not be confused with corning ware, a form of earthenware, which will be discussed later in this article.)
Utensils do not require tevila, even if they have direct contact with food during preparation or meal time, if they are made from bone, non-glazed earthenware (flower pot dull finish), paper, plastic, stone, styrofoam, or wood. Other instances not requiring tevila include:
1. Utensils made from metal or glass whose intended purpose is not for food usage, e.g. an arts and crafts knife. Even if the knife was to be used occasionally for food preparation, tevila would not be required.
2. Metal or glass utensils that do not come into direct contact with the food, e.g the metal shell of a removable crock pot or can-opener.
3. Utensils which are made by a Jewish craftsman (observant or non-observant) who owns his company or business and are sold directly to a Jewish customer.
4. Empty metal cans that previously held food, e.g canned vegetables, can be used to cook food therein without tevila. One does not have to immerse the can because the Jew who opened the can to remove the original contents has now created a "new" utensil.
5. Storage utensils that are not brought to the table, e.g. glass spaghetti/pasta containers or ceramic cookie jars.
6. Food sold in glass jars (mayonnaise jars or juice bottles): When it is emptied, the glass jar does not require tevila due to the fact that it is secondary to its contents. If a deposit is required on the bottle, the glass has individuality in its own right and would require tevila before reuse. In the event that the jar or the bottle is fancy and important in its own right, tevila would be required. A competent halachic authority should determine whether a brocha is required when making the tevila. One should not assume that Jewish merchants immerse the jars of bottles used to package loose or bulk food items.
7. Utensils used exclusively with raw, non-edible food, for instance cookie cutters or a metal tenderizer hammer do not need tevila.
Utensils require tevila without a brocha when the dishes or vessels are made from glazed china, bone china, stoneware, corning ware, or porcelain enamel. Other vessels requiring tevila without a brocha include:
1. Utensils made from a combination of materials, e.g. metal pots coated with teflon or enamel.
2. Utensils used for raw ingredients, but could also be used for edible food, such as mixer beaters, should be toveled without a brocha.
3. Metal utensils used for food storage that remain in the kitchen or pantry and are not brought to the table, e.g. metal flour or sugar canisters.
4. Disposable aluminum pans and containers used for cooking and baking require tevila with a brocha if they are to be used more than once. If they are to be discarded after one use, a competent Rabbinic authority should be consulted.
Instructions for Tevilas Keilim:
The vessel/utensil to be immersed must be completely clean - free of dirt, dust, rust, stickers, or glue. If the utensil was immersed with a label, a Rabbinic authority should be consulted.
The immersion must be done in a mikvah, a ritualarium, which is kosher for tevilas noshim (a mikvah that is kosher for men only does not qualify). One may also use the ocean and rivers that flow the entire year. If there is no alternative, rivers that flow due to rain or snow can be used for tevila only after settling. In all cases, the water of the mikvah, ocean and/or river must touch the entire utensil inside and out.
In case of great need, it is permitted to tovel glass and china in snow if there is at least 240 cubic feet of snow joined together in any area. For example, four inches of snow in a field which has an area of 27' X 27' would be large enough to tovel vesels. The snow must fill the inside and cover the outside of the vessel, and the vessel must be connected to the required amount of snow.
Anyone may tovel keilim, including a small child or a non-Jew. The tevila must be done in the presence of a Jewish adult to verify that it took place. The recitation of a brocha can only be said if an adult Jew does the immersion. Therefore, if many utensils are to be immersed with the help of a child or a non-Jew, the owner should first immerse a few vessels with a brocha and the child or non-Jew can take over.
Prior to the immersion of metal or glass utensils, one wets his or her hand in the mikvah water, holds the vessel in the wet hand says Baruch....al tivilas keilim and immerses the vessel. The water of the mikvah must touch the entire vessel inside and out. The entire vessel must be under the water at one time. The cover can be toveled separately if it is removable. If only one vessel is immersed, the above procedure is followed and the brocha al tivilas keili is recited.
Under no circumstances can a utensil be toveled in parts, nor can two keilim touch each other during immersion. Utensils comprised of separate pieces that are used together as a single unit, e.g. a meat grinder or thermos bottle, may be toveled in the manner used and not piece by piece. When toveling an assembled appliance, it is imperative that the water touch all areas that the food will touch during use, both inside and out.
If it is impossible to tovel a utensil because the utensil is too large to immerse in a mikvah, if there is no available mikvah, if the vessel will be ruined when placed in a mikvah, or if immersion may present a hazard, a Rabbinic authority should be consulted. A possible suggestion would be to disassemble the vessel and have a Jew reassemble the vessel. Reassembly would not apply to the parts of a meat grinder that are regularly assembled and disassembled during ordinary use. Reassembly would apply to utensils that don't ordinarily get dismantled. Another suggestion would be to give the utensil in question to a non-Jew as an outright gift and borrow it back from the non-Jew. However, this procedure only helps for one day, such as Shabbos.
Essentially, each specific question should be evaluated by a Rav so that an appropriate halachic ruling can be made.
A pocket knife used for food should be toveled in its open position so that the water will touch all areas of the blade. A narrow necked bottle should be toveled neck up so that the inner surface of the bottle will fill completely with mikvah water. It is important to emphasize that if a utensil requires tevila, it may not be used even once before the tevila is done. If a utensil was used numerous times without tevila, one is still required to immerse it before its next use.
Even if all the workers that manufactured the utensils are Jewish, the utensil requires tevila if the company is owned by a non-Jew. This halacha applies to companies whose whole ownership is completely held by non-Jews, or if non-Jewish owners hold partial ownership. Similarly, a company that has non-Jewish voting stockholders would also qualify for non-Jewish ownership. Unless one has information to the contrary, one should assume that all companies outside Eretz Yisroel have some public non-Jewish ownership.
If a utensil which was owned by a Jew and was toveled fell into disrepair and the utensil was no longer functional, e.g. a hole or crack on the bottom of a pot, and a non-Jewish repairman welded a new patch on the broken area the newly repaired vessel would require tevila again. This is due to the fact that the newly functional vessel is considered to be brand new. A Rav should be consulted to determine whether a brocha should be said on a repaired vessel.
If one bought a used vessel which needs to be kashered, e.g. from a non-Jewish owner, the keili must be kashered before it is toveled. If the order was switched, a Rav should be consulted.
Utensils require tevila if they were given to a Jew as a gift from a non-Jew or bought from a non-Jew. This requirement would apply even if the Jew owned the utensil originally, sold it to the non-Jew and subsequently bought it back. It is for this reason that one does not sell chometz keilim to a non-Jew. If someone converts, their utensils require tevila, even if they were only used for kosher food, since the utensils went from the possession of a non-Jew to the possession of a Jew.
If one borrows or rents utensils from a non-Jew or from a Jewish/non-Jewish partnership, tevila would not be required. If utensils are purchased from the partnership or if the Jew buys out the non-Jewish partner and now has total ownership of the utensils, tevila with a brocha is required.
Tevilas keilim may be done by day or night, except Shabbos or Yom Tov. In case of great necessity, where one needs to use an untoveled keili on Shabbos or Yom Tov, the utensil should be given to a non-Jew as a present and the Yehudi should borrow it back. After Shabbos, if the Yehudi re-purchased the utensil from the non-Jew, it must be toveled with a brocha. If the Yehudi continues to use the keili without paying for it, the keili will require tevila without a brocha. If one is in doubt whether a keili needs tevila, a Rav must be consulted. If one is in doubt if a vessel that requires tevila was toveled, it should now be immersed without a brocha.
If a keili that requires tevila was mixed together with utensils that have already been immersed and the untoveled one is unidentifiable, all of the vessels should be retoveled. If this poses a difficulty or expense, a Rav should be consulted.
If one is invited to eat at a friend's house and it is known to you that his/her utensils have not been toveled, since the guest is aware that a problem exists, a Rav should be consulted. However, it is not proper or necessary to investigate if the host complies with the laws of tevilas keilim since we assume G-d fearing Jews comply with the halacha. If by mistake a non-toveled utensil was used to prepare food, the food is still kosher and must be eaten on properly toveled dishes.
In conclusion: It is obviously difficult to address all of the issues and questions one may have regarding tevilas keilim in this brief article. Of course, when in doubt about a particular facet of this mitzvah, always consult with a competent Rabbinic authority. Let us hope that fulfillment of this mitzvah will add an enhanced kosher flavor to the sanctity of our home.
Topic: Kosher Cooking Question (Read 3530 times)