First Quaff

The Dwarf holiday of First Quaff is when the first kegs of new beer are tapped for an initial tasting. It is held on the 33rd of Pflugzeit, and while this is a time of great celebration, it does take on a rather ominous tone, as the quality of beer is seen as a form of augury for the fortunes of the Dwarf Hold for the next year. If the first keg is of inferior taste or colour, it indicates bad luck for those tasting it. However, a fine brew points towards good and glorious times ahead. An entire system of divination has developed for this tasting, and thus, the hold’s runelord and king are always the first to sample the year’s yield.1a

Source
Warhammer Fantasy RPG 2nd ED -- Tome of Salvation -- pg. 144