Given the range and variety of the existing types of Grappa, it is more correct to speak of “grappas,” each with its own specific characteristics, rather than Grappa in the singular.
Owing to the geographic origin of the pomace and the distillation process typical of different regions, each Grappa produced in Italy has its own particularities and variations.
There are several criteria for classifying the wide variety of grappas according to age and post-production processing.
The first classification, based on the number of grape varieties from which the pomace comes from, divides grappas into:
- single vine varieties (monovarietal): produced with pomace from just one type of grape. The law allows grape variety to be indicated only if at least 85% of the pomace comes from the same grape.
- multiple vine varieties: produced using pomace from several varieties of grape. If each variety exceeds 15%, they must be listed on the label in ascending order.
Another distinguishing element in the classification of grappas is aging, which runs in barrel from a period of 12 months (aged) to 18 months (reserve), but can even last 15-20 years.
Unaged Grappa is the young type which, before being bottled, is left to rest in neutral steel or glass containers. It is colorless and transparent, with a delicate, fruity scent and a dry, clean, subtle taste.
During aging, chemical-physical reactions take place affecting the bouquet of the Grappa which, depending on the length of maturation and the qualities of the barrel wood, exhibit different aromas and coloring. The barrels are usually made of oak, ash or chestnut, but can also be made from cherry, acacia and almond tree wood.
The coloring displayed by aged Grappa ranges from straw yellow to darker, amber shades. In terms of taste, aged grappas are usually smoother than white ones.
The bouquet and aroma of Grappa, on the other hand, is influenced by substances contained in the wood, one of the most important of which is lignin. These substances give each Grappa unique scents and aromas, from the most delicate that bring to mind sweet spices, vanilla or tobacco to the more intense cocoa, liquorice or cinnamon.
Depending on the length of aging, grappas are classified into:
- aged or old, which remain in the barrel for a period of at least 12 months
- very old or reserve, which aging period is at least 18 months.
Aging takes place in warehouses, subject to regular fiscal controls by the Italian customs authorities, thus guaranteeing the quality and aging of the product to the consumer.
Finally, one last distinction is that between aromatic and flavored grappas. The former type derives its main features from the raw material itself, consisting of aromatic or semi-aromatic grapes. In this case, grapes rich in terpenes – aromatic elements conferring the perfume transferred to the distillate during the production process – are chosen. Whereas flavoured grappas are young grappas where aroma and color are determined by the steeping of fruit or herbal plants.
Steeping herbal plants in the distilled spirit, including leaves, roots, bark and whole twigs, is the way to obtain this flavoured grappas: as the cranberry or liquorice one.
The maturation process generally lasts a couple of weeks, after which the distillate is filtered to make it pure and transparent, even though the infused essence can release some light clouding.