One of the most common questions about keeping kosher, apart from “what’s the point?”, is “What makes a wine kosher or un-kosher?”. Ritual slaughter for meat? Fair enough. Not to mix meat and dairy? OK. But what can possibly be wrong with wine and grape juice? If any freshly squeezed orange juice is kosher and even eating grapes is fine, what can be the problem with squeezing a few grapes and letting them ferment? Well, as always with Jewish rituals, nothing is simple.
It’s not hard to see that wine holds a special place in Jewish life. The Garden of Eden’s forbidden fruit was, according to tradition, grapes. When Noah came out of the Ark after 40 days of the Flood and total destruction the first thing he did was plant a vineyard and get himself drunk (probably understandable after such an ordeal…). The starting point of every Shabbat or Holiday meal is Kiddush, the blessing over wine. A cup of consecrated wine also plays a key role during the wedding and circumcision ceremonies. Wine has special elevated spiritual properties and must therefore be made and handled with extreme care.
Apart from not containing any non-kosher ingredients (yeasts, preservatives, etc) the basic rule is that wine must be produced, bottled, opened, handled, and poured by Shabbat-observing Jews only. Even if a non-Jew just passes the bottle to a Jew the wine loses its kosher status. Now that’s pretty radical and is unlike any other kosher food where handling by non-Jews is certainly permitted.
However, as is so often the case in Jewish law, there is a workaround solution: to make the wine Mevushal. The Mevushal (which means ‘cooking’) process involves heating the wine to near-boiling temperature. By doing this the wine loses some of its ‘spiritual’ value, allowing non-Jews to touch the wine without rendering it un-kosher. Using Mevushal wines in restaurants and catering events greatly facilitates their handling. Obviously, heating up wine like this will have an effect on the taste, so producers have started using flash-pasteurising techniques which reduce the side effects of the heating process. Flash-pasteurisation even seems to enhance the flavour of the wine. The most recent development is called ‘Flash Detente’ which involves heating the grapes themselves to about 180 degrees F and then cooling them within a vacuum chamber. All this before the grapes are even pressed. High tech stuff… (read more about this process here)
So, for Kiddush and other religious rituals it is best to use non-Mevushal wines (often marked as ‘for sacramental purposes only’) but anything else look out for the word ‘Mevushal’ on the label.