Funny Scottish tradition

In Scotland, there is a tradition: in November freshmen university, since ancient times, were "grandfathers" in the sense of undergraduates, to give something like a payoff. In the old days this was the mercy of a pound of raisins. But this tradition is strangely transformed the gift of a bottle of wine (in principle, it is logical) and ... everybody pouring foam! ))) What I have is not so logical - but pretty darn fun!