Assessment of colour and aroma in white wines vinifications: Effects of grape maturity and soil type

White wines were elaborated in an experimental winery from grapes (Vitis vinifera   cv. Zalema) at different degrees of maturity and grown in different soil types. The effects of these factors on the quality characteristics, in terms of colour and aroma profile, of the wines at bottling were evaluated. Two types of soils (sand and clay) and two different harvest dates (early harvest and industrial harvest) were considered. With reference to colour, the highest colour differences (ΔEab∗=2.37±1.05) were observed between wines from sandy soils and different harvest dates. Wines from sandy soil and early harvest date showed a more yellow-pale colour and lesser colour intensity. However, these differences were hardly appreciated by tasters. On the contrary, effects of harvest date and soil type were more marked regarding the aromatic profile of the wines. Results showed that in order to elaborate a white wine of quality, in the case of grapes from clayey soils, the harvest date should not be postponed because it would cause a decrease of fresh aromas and an increase of “ripe fruit” notes, no favourable aromatic notes for a young white wine.