Grappa is an alcoholic beverage, a fragrant, grape-based pomace brandy of Italian origin that contains 35 to 60 percent alcohol by volume (70 to 120 US proof).n Italy, grappa is primarily served as a digestivo or after-dinner drink. Its main purpose is to aid in the digestion of heavy meals. Grappa may also be added to espresso coffee to create a caffe caffè, corretto meaning correct or proper. coffee