How to Keep a Kosher Kitchen
Note: The following comes from a Conservative perspective. For practical halachic advice on how to kasher your kitchen (instructions may vary depending on the contents of your kitchen, such as the sink and dishwasher) — and there are often multiple opinions on the correct procedure — consult a halachic authority such as your rabbi.
To maintain a kosher house, you must allow only reliably-supervised kosher food into your house. But, beyond that, your entire kitchen and eating areas must also be kosher. Here are some guidelines:
Dishes and silverware
It is essential to have seperate sets of dishes for dairy products and meat. It is best to have two distinct colors, patterns or styles so that you will not be confused when you look at a plate or a fork as to whether it is for dairy or meat.
Cabinets, drawers, and trays
To help avoid confusion, it is best to designate separate cabinets for the dairy equipment and meat equipment. If you have cabinets on two sides of the kitchen, you may want to put the meat on one side and the dairy one on the other to avoid confusion. When you first organize your kosher kitchen, it is wise to label the cabinets on the outside as "Dairy [Chalav]" and "Meat [Basar]." You can use masking tape or colored file dots that you can get from a stationary store (red and blue are popular to be used, red for meat, blue for dairy). Many Judaica stores and online Judaica shops also sell various styles of labels for meat and dairy. You will also find these labels come in handy if you have guests and they want to put the dishes away or take them out. If you have a housekeeper, labeling helps make sure no mistakes are made.
Tableclothes, napkins, and placemats
As with the kitchen, the dining room/eating area maintains the separation of meat and dairy foods by using separate utensils. This includes seperate tablecloths, (cloth) napkins, placemats and other similiar items.
While laundering may be suitable to kasher them (particularly if mistakes are made), it is advisable to have a seperate meat and dairy set because you may forget before using them which type of food was eaten on them last.
When placing food in the refrigerator, care should be taken to avoid contact between open packages of meat and dairy products.
One should not use the oven for dairy and meat at the same time. Between using the oven for dairy and meat, the oven should be cleaned (wiped up) if spillage has occured. Electronic self-cleaning ovens can be kashered simply by cleaning up spills and running the self-cleaning cycle, however, oven manufacturers generally recommend that the self-cleaning cycle not be used more than once or twice a year due to the extremely high heat that the self-cleaning cycle generates.
Spills on the stovetops should be cleaned, particularly in between using the stove for meat and dairy foods. This is especially true if you tend to rest pot lids on the stovetop when cooking. There is no need to designate seperate meat and dairy burners. It is best to avoid cooking meat and dairy foods on the same stovetop at the same time to avoid spillage. If you must do so, extra care should be taken to ensure that no spillage or transfer or liquid or heat occurs and to ensure that your pots are covered tightly.
It is best not to use a microwave oven for cooking meat and dairy foods at the same time because microwave covers usually have holes in them that allow fumes to escape.
Because the sink itself is made of material that is not kasherable, sink racks (that fit on the bottom of the sink and keep the dishes from touching the bottom) or a tub (which can be used for soaking the dishes) are put into the sink. Separate racks or tubs must be used for dairy and meat.
Metal sinks may be kashered by pouring boiling water in them. The water must be boiling before you pour the water in and remain boiling as it comes into contact with the metal lining of the sink. There should be a separation (such as racks or tubs) between meat and dairy dishes.
There is a difference of opinion as to how to use dishwashers:
Source: United Synagogue of Conservative Judaism, adapted from their interactive CD "Kosher - Sanctifying the Ordinary"