In an earlier post, I mentioned that Dr. Haym Soloveitchik has pointed out that there is no evidence to support the common claim that Rashi was a vintner. Here is the exact quote from Dr. Soloveitchik's article "Can Halakhic Texts Talk History?" in AJS Review 1978, pp. 172-173:
Jewish communities were generally tiny, averaging from a handful to a score of families and tended (in the county of Champagne) to make their own wine. As the crude state of barrel making made the ageing of wine and its long-range storage impossible, wine was usually produced anew every fall. An entire year's consumption had to be provided for in the treading of September and early October, but since the High Holidays and Sukkot fell in these months, the time available for grape pressing was limited indeed. In contrast, the quantities of wine consumed in this age was (as we have already noted) enormous, and it was taxing in the extreme to tread so large a quantity in so short a time with little manpower. It is difficult to see how this was accomplished without the concerted effort of the entire community.
 It is this (rather than any professional occupation as a vintner) that explains Rashi's oft-cited remarks (Teshuvot, no. 382), הלב יודע טרד המצוי באגור ביקבים, על כן לצדק יכריעני אדוני ר' עזרא את קוצר מילי. The average Champagne household in the month of September very much resembled our own before Passover. The second passage usually cited in support of Rashi's supposed occupation (Ha-'oreh, p. 214, Teshuvot, no. 159) refers most probably to R. Isaac b. Judah. In the literature of his school Rashi is never called רבינו הגדול, but the former scholar is regularly referred to this way by the Makhirites in the Ma'asei ge'onim. Indeed the presumption is against anyone being a winegrower in Troyes. Its chalky soil to this day is inhospitable to viticulture, and not surprisingly Elizabeth Chapin has fonud no references to vines in local documents (Les villes des foires de Champagnes des origines au debut du XVIe siecle [Paris, 1937], pp. 97-98. Contrast this with their frequent mention in the Bar-sur-Aube region, ibid., pp. 77-92.). A generation or so before Rashi there seems to have been one solitary owner or, perhaps, more accurately, only one major owner of vineyards among the Jews of Troyes (Teshuvot R. Me'ir mi-Rotenburg [Budapest, 1895], no. 941 and note ad loc.). Undoubtedly there were some local vines, probably for private use (Rashi's words almost imply as much), but that they should have regularly produced a surplus sufficient to afford a living is asking a great deal of them. Despite all this, Rashi may have been a vintner; but by the same token he may have been an egg salesman.