The term "5 Puttonyos" refers to the level of sweetness and concentration in the wine. It indicates that the wine is made with a higher proportion of aszú berries (botrytized grapes) relative to the base wine. The puttonyos system ranges from 3 to 6, with 5 puttonyos being quite sweet and rich. The primary grape varieties used in Tokaj Aszú wines are Furmint, Hárslevelű, and Muscat Blanc. These grapes are particularly susceptible to noble rot (Botrytis cinerea), which concentrates their sugars and flavors.