In my early 20s I worked at a wine merchant in Leeds in the north of England. Customers would regularly inquire, usually before Passover, about kosher wine. I would point them to the bottle of Palwin No. 10, a red dessert wine from Israel, on the top shelf, the label almost unreadable from age and dust. Without fail the customer would make a face and say that they wanted something to enjoy, not kiddush wine (ceremonial wine). At least Palwin is made from respectable grape varieties, mainly Carignan, and sweetened with grape juice. The American equivalent, Manischewitz, is made from Concord, a native American grape with a taste generally described as foxy, and sweetened with high fructose corn syrup. Classy!
Without really thinking about it, I assumed that there was something intrinsically different about kosher wine, hence the unique taste of Palwin et al. Jeff Morgan, an American winemaker I met at a kosher wine tasting in London, put me right: "The grapes are the same as for non-kosher wine. Any other ingredients such as commercial yeasts and fining agents just have to be certified kosher. Kosher wine is made in exactly the same way as non-kosher." There's one difference, however. "From grapes arrive at the winery," Morgan says, "they can only be handled by sabbath-observant Jews."
Despite being Jewish himself, Morgan isn't observant enough to physically make kosher wine. He doesn't mind, and compares his role to that of a conductor in an orchestra. This strictness in handling emphasizes how sacred wine is in Judaism. Kosher food can be prepared by anyone, as can alcoholic drinks made from other fruit. With wine even the bottling can only be done by sabbath observant Jews. What happens to it after that, however, is according to Morgan "open to interpretation." Some say the wine can only be poured by observant Jews, and other disagree. At the Kedem kosher wine event I attended in London earlier this year they had a crew of eager young men in kippahs pouring the wine in enormous drinking measures rather than tasting samples.