Grappa is an Italian alcohol which is made by distilling pomace, the leftovers of winemaking. The name is in fact a reference to this, as it means "grape stems" in an Italian dialect. Many winemaking nations have their own versions of this drink, and they tend to be very strong, fiery, and incredibly diverse. Grappa is probably most similar to brandy. Many Italian importers carry an array of grappa, and it can also be found stocked at some large markets.
The main ingredient of grappa is pomace, which consists of the grape skins, seeds and stalks that are left over from the winemaking process. These are taken through a second process of distillation, which extracts the remaining flavours from the pomace before the waste is discarded. The grappa is then either bottled at once, which creates white grappa (grappa bianca), or aged in wooden casks to create the yellow or brown-hued grappa known as riserva.
Many Italian households serve grappa straight from the freezer, giving it an icy, crisp taste, while the Instituto Nazionale Grappa recommends serving young grappa at between 9 and 13 degrees Celsius, and riserva at around 17 degrees.