Although Jews were at the centre of commercial activity in medieval
Europe, a talmudic ban on any wine touched by a Gentile prevented them from
engaging in the lucrative wine trade. Wine was consumed in vast quantities in
the Middle Ages, and the banks of the Rhineland hosted some of the finest
vineyards in northern Europe. German Jews were, until the thirteenth century, a
merchant class. How could they abstain from trading in one of the region’s
major commodities? In time, they ruled that it was permissible to accept wine
in payment of debt, but forbade trading in it, and they maintained that ban
throughout the Middle Ages.

Further study in the twelfth century, however, led Talmudists to
discover that Jews were only forbidden to profit from trading in Gentile wine
if they dealt with idolaters, but that trade with Christians and Muslims was
permitted. Nevertheless, the German community refused to take advantage of this
clear licence. Using Jewish and Gentile sources, this study probes the sources
of this powerful taboo.

In describing the complex ways in which deeply held cultural values
affect Jews’ engagement in the economy of the surrounding society, this book
also illustrates the law of unintended consequences—how the ban on Gentile wine
led both to a major Jewish contribution to German viticulture and to the
involvement of Jews in moneylending, with all its tragic consequences.