In Judaism, a Mashgiach (Hebrew: משגיח) is a person who supervises the kashrut status of a kosher establishment.A Mashgiach may supervise any type of food service establishment, including slaughterhouses, food manufacturers, hotels, caterers, nursing homes, restaurants, butchers, or groceries. The mashgiach usually works as the on-site supervisor and inspector, representing the kashrut organization or a local rabbi, who actually makes the policy decisions for what is or is not acceptably kosher. Sometimes the certifying rabbi acts as his own Mashgiach; such is the case in many small communities. RequirementsThe usual requirements for becoming a Mashgiach are being Jewish, observing Shabbat, the Jewish sabbath (shomer Shabbat), keeping the laws of kashrut (shomer kashrut), and doing mitzvot, the commandments of the Torah (shomer mitzvot). Different rabbis will have different requirements. Even the same rabbi may have different requirements dependent on the type of establishment being supervised. (For example, supervision of a slaughterhouse will be very different to supervision of a grocery.) Sometimes the only requirement is that the person is Jewish and knowledgable of the laws of kashrut.Regardless of the specific eligibility requirements of a Mashgiach, he or she takes on a great responsibility and the burden of a community. The Mashgiach puts his or her good name and the name of the community on everything that is done on his or her watch. ResponsibilitiesA Mashgiach is required whenever meat or fish is being prepared or cooked. He or she checks all fresh eggs for blood spots before they are cooked or mixed into batters and dishes. He or she must inspect all vegetables thoroughly for forbidden insects before they can be used.The Mashgiach' is responsible for taking challah, the tithe of dough set aside for kohanim serving in the Temple in Jerusalem. Because the Temple is currently not erected, the challah is burned in its stead.The Mashgiach must also light pilot lights and turn on cooking and heating equipment to satisfy minimum requirements of Bishul Yisrael, (food cooked by a Jew), and Pas Yisrael, (bread baked by a Jew), that a Jew must be involved in the cooking of any kosher food "fit for a king's table."One of the most pressing and often difficult jobs of a Mashgiach, however, is the checking in and verification of shipments. The Mashgiach must ensure that every food product that arrives at the facility has a reliable hechsher before it is used. Suppliers often substitute products that are out of stock with non-kosher products. Non-kosher establishments would generally not mind these substitutions. For a kosher establishment, however, these substitutions can cause major problems. If a product arrives without a hechsher, he or she has to make sure the product is clearly marked as non-kosher and is not used until it is returned to the supplier. Sometimes a product arrives that is purportedly kosher, but no hechsher can be found. In this case, the mashgiach obtains a valid letter of certification from the certifying rabbi or kashrut agency, usually by contacting the manufacturer. In addition to checking hechsherim, the Mashgiach must also check that all meat products that arrive are double sealed, usually by inner and outer plastic bags or an inner plastic bag and a sealed box, and that all wine is kosher wine.A Mashgiach plays social as well as technical roles in explaining kosher rules to the Jewish and non-Jewish community and forging close relationships with employees and customers.