Koshermeans fitting (food that is fitting to eat).
Kosher Food Spilling in Non-Kosher Oven
If kosher food spills inside a non-kosher oven in which you are cooking uncovered kosher food (whether liquid or non-liquid), consult a rabbi about whether the uncovered kosher food may still be eaten.
Note In this case, it makes no difference whether the oven is clean or dirty because the spilled food is wet and takes on the non-kosher status of the oven. When the spilled food vaporizes, it carries the non-kosher essence to the kosher food or utensil. Note If the non-kosher oven had not been used for more than 24 hours, the food is probably still kosherb'di'avad. Note This applies to food spilled either from the same utensil in which you were cooking the kosher food or from a different utensil.
Eating Kosher at a Non-Kosher Event
You may eat a kosher catered meal at an otherwise non-kosher event as long as:
Your food is obviously different from the non-kosher food, and
You have kosher dishes and utensils to use.
Your food must be separate from the non-kosher food. Reason
To avoid mar'it ayin--the appearance of doing something improper.
Non-Kosher Microwave Oven: Non-Hot Oven
If the walls of a non-kosher microwave oven stay less than 120° F, you need not wrap or cover liquid or non-liquid food, as long as:
The microwave oven is clean and dry, and
If the tray is non-glass or non-Pyrex, you put a layer of separation (plastic, styrofoam, etc…) that blocks heat and any moisture underneath the cooking utensil.
Non-Kosher Microwave Oven: Hot Oven, Liquid or Solid Food
If the walls of a non-kosher microwave oven get hotter than 120° F, you must double wrap any liquid or solid food you cook in that oven.
Note If you did not double wrap liquid or solid food cooked in a non-kosher microwave oven, consult a rabbi about whether you may eat the food.
Non-Kosher Oven: How To Double Wrap
When wrapping food for cooking in a non-kosher oven, the wrapping material does not need to seal completely, but the:
Food must be completely covered with two layers of foil or plastic;
Layers must keep water vapor out from between the layers; and
Surfaces of the utensil must all be covered.
Non-Kosher Oven: When To Double Wrap
Double-wrap food before baking in a non-kosher radiant-heat oven if:
The food that you are baking is liquid at any time during the cooking process; OR
Some of the food you are baking spills onto the rack or oven surfaces.
Non-Kosher Mouthwash
You may use non-kosher mouthwash, even if you may swallow some residual mouthwash, as long as you do not intend to swallow the mouthwash.
Note On Passover, you may not use chametz mouthwash.
Microwave Oven: Kosher Status: Walls and Door
Since microwave oven walls and doors do not normally get hot (more than 120° F, or 49° C),there is usually no need to kasher them from milk to meat (or back to milk); from ordinary use to Passover use; or from non-kosher to kosher. Just clean all surfaces.
Rivers as Kosher Mikva
Rivers are only koshermikvas when spring-fed. A river is a koshermikvaif it exists year round (not like a wadi, which is frequently dry and only flows after rainfall).
Microwave Oven: Kosher Status: Floor
Microwave oven floors can get hot, especially where there is no rotating glass tray and the utensil is placed directly on the oven floor.All microwave ovens should be assumed to get hot unless you have tested them personally. Microwave Floor Cover the floor (ideally with styrofoam or another substance that blocks heat and moisture).
Glass Tray The glass tray does not become non-kosher and does not become dairy or meat or chametz (unless it was removed and used in a conventional oven) as long as it is clean. Plastic Tray Support The plastic support under the glass tray must be cleaned and must be blocked from contact with actual cooking utensils and from food if the tray:
Has any food of the gender opposite that of the food being cooked,
Has non-kosher food on it, or
Is dirty and you cannot tell with what.
Microwave Oven: Kosher Status
If a microwave oven's walls/floor/door do not become hot (more than 120° F, or 49° C), the microwave oven does not become non-kosher, dairy, meat, or non-Passover/chametz.
A microwave oven that does not normally get hot, may get hotter than 120° F if you cook:
A liquid or moist food for a long time (even if less than 10 minutes),
Several liquid or moist items sequentially, or
Popcorn and similar foods.
If a microwave oven's walls/floor/door get hot, the oven can become dairy, meat, or non-kosher (if they become one gender and then the opposite gender is cooked or if non-kosher food has been cooked in it). If any surface--including walls, door, floor, etc.--that gets hot are plastic or coated metal, it cannot be returned to kosher or pareve. However, if the surfaces are all made of metal, they may be kasherable. Consult a rabbi.
A non-kosher substance becomes kosher once it is modified and no longer has the original taste.
Example Animal bones are burned for charcoal to filter cane sugar from molasses in order to make white sugar. The bones are not only not non-kosher, they are pareve. Note Rabbinic supervision is required to ensure that the bones have been completely burned.
Lanolin Not Kosher
Lanolin is not kosher.
Stovetop Surfaces: Kosher Status
A stovetop surface is likely to be non-kosher due to previous spills of both genders. Reason The stovetop will have been heated to more than 120° F (49° C) from:
