Kosher is an ancient Hebrew word that translates to “proper” or “fit.” When applied in winemaking, this term is used when the wine is produced in accordance with Jewish dietary laws. Though it doesn’t necessarily contain any ingredients that are non-kosher, wine, more than any other food or drink, stands as a representation of the holiness and separateness of the Jewish people. As such, there are extra restrictions placed on the making and handling of wine.
Firstly, the wine must be produced and prepared (from harvest to service) under the supervision of a rabbi. Throughout this entire process, the wine may only be handled by Sabbath observant Jews. All equipment used in the winemaking process must be thoroughly cleaned, with the barrels to be cleaned 3 times and used exclusively for the production of kosher wine. Only kosher yeast and fining agents may be used. While casein, isinglass, gelatin and egg whites are often used to clarify wine, to obey the dietary laws, no animal products may be used. Kosher winemakers will use bentonite (a type of clay) as a fining agent, which pulls the suspended particles to the bottom of the barrel.
Mevushal wines are kosher wines that allow for a little flexibility of the service of wine. A wine that is Mevushal it has been ‘cooked’ or ‘boiled’ and so has become unfit for a non Jew thereby keeping its kosher status even if handled by a non Jew. Kosher wines served in restaurants, for example will be Mevushal, thus allowing the waiter to be a non observant Jew. The down side to this however, is that heating a wine can have detrimental effects on its flavor. In recent years, a solution for this has been developed improving the flavor, and in turn, the reputation of Kosher wines. Flash pasteurization was used by kosher wineries to make Mevushal wines. Here, the wine is brought to around 185 degrees Fahrenheit before quickly being brought back down, with the whole process lasting only a few seconds. This process is said not to have an effect on the flavor of the wine and can in fact be heated for 10 times longer than the time flash pasteurization takes before there are noticeable changes to the flavor of the wine.
In the United States, Kosher wines have long held a negative reputation, as they have always been associated with sweet Concord wine (think Manischewitz). A movement starting in the 1980s toward producing dry, premium quality kosher wines, led the revival of the Israeli wine industry and is slowly changing the way kosher wine is regarded and produced throughout the world. This movement has been based on a shift away from the use of the Concord grape towards other grape varietals known to produce higher quality wines. Since the focus is on the process of production, not the grape varietal, virtually any wine grape can be made into a Kosher wine!