Hops "made in Italy": do Italians do it bitter?

The aim of this work was to evaluate the adaptability of some hop varieties to the soil and climate of the North East (NE) of Italy (Udine); in particular, 21 varieties grown in Udine were compared with the corresponding varieties of the market. The brewing value of hops is primarily attributed to the precursors of the flavour- and bitter-active compounds found in the resins (α- and β-acids) secreted by the lupulin glands; it is well estabilished that the α-acids are by far the most important constituents of the hop resins (Urban et al., 2013). Furthermore, cohumulone was said to elicit a harsh and unpleasant bitterness when superior to 30% of the total α-acids (Intelmann et al., 2009). The hop essential oils are also important to the brewer as they provide flavour and aroma characteristics to the beer. The bulk of the hop oil is made up of hydrocarbons and oxygenated components. The hydrocarbons can be classified into three groups: aliphatic hydrocarbons, monoterpenes and sesquiterpenes. In the hydrocarbon fraction, the most important and abundant monoterpene is β-myrcene, the major components of the sesquiterpene group are α-humulene, β-caryophyllene and β-farnesene (Almaguer et al., 2014). It is known that both α-acids and composition of the total essential oil of hops are affected by numerous factors such as hop variety, environmental, drying and storage conditions (Hautke and Petříček, 1967).