Historically, fortified wines originated in Europe, and they have in common a high alcohol content to increase their shelf-life during long journeys to northern Europe and the American continent. Nowadays, the world’s better-known Marsala, Port, Sherry, and Vermouth due to their high alcoholic content, sweet taste, and intense aromatic profile, are designated as dessert wines and sometimes served as aperitifs. This review gives an overview of the traditional vinification process, including the microbiota and autochthonous yeast, the use of aromatic botanicals, and regulatory aspects of the main Italian, Portuguese, and Spanish fortified wines. The wine-making process is essential to defining the volatile organic compounds (VOCs) that characterize the aroma of each fortified wine, giving them an organoleptic fingerprint and “terroir” characteristics. The various volatile and odorous compounds found in fortified wines during oxidative and thermal aging are discussed in the last part of this review.

Torulaspora delbrueckii showed renewed interest in recent years in the fermentation of wine, for its biotechnological potential linked to the ability to enhance flavor and aroma and it probably is the non-Saccharomyces yeast currently widely used in winemaking. On the base of this, sequential fermentations with a selected native strain of T. delbrueckii (DiSVA 130) and low sulfite native strain of Saccharomyces cerevisiae (DiSVA 709) were carried out to establish their contribution in biocontrol and aroma profile. A first set trials, carried out in winery, were set up to establish the effect of the sulfur dioxide addition on pure and T. debrueckii/S. cerevisiae sequential fermentations. A second set of sequential fermentations without SO₂ addition were conducted in the same conditions, to evaluate the biocontrol and aromatic effectiveness of the T. delbrueckii native strain and a commercial one. The effective biocontrol action of native T. delbrueckii inoculated in sequential fermentation was shown, indeed without SO₂ addition the presence of native T. delbrueckii revealed an effective fungistatic action in the first two days of fermentation. Moreover, the native T. delbrueckii strain seems to have fermentative performances comparable to those of T. delbrueckii commercial strain showing a more evident biocontrol action (wild yeasts reduced by c.a. 1 Log at 2^nd day) and its presence did not negatively affect S. cerevisiae fermentation activity. Finally, the combination of both native and commercial T. delbrueckii/S. cerevisiae trials led distinctive aromatic profile of wines with a significant enhancement of isoamyl acetate, phenyl ethyl acetate, supported by positive appreciations, from the tasters, for ripe and tropical fruits, citrus and balance. The whole results indicate that the proposed strain could be a potential biocontrol tool toward wild yeasts in the first phase of fermentation also contributing to improve and differentiate the final aroma wine.

Red fruits such as grapes and blueberries are known for their high content of bioactive compounds and antioxidants. In Mediterranean winemaking, traditional sun drying can be replaced by controlled airflow chamber drying which provides better quality, higher phenolic content, and increased antioxidants. This study aimed to increase the sugar content and phenolic compounds of the must by drying the fruits to 50% of their original moisture content. Two musts were prepared by combining fresh grapes and dried blueberries (M1), and the other using dried grapes and fresh blueberries (M2), followed by fermentation at 25 ºC with M05 Mead and X5 yeast strains. Must M2 showed the highest level of phenolic compounds, A520, total anthocyanins and antioxidant activity. During fermentation, the anthocyanin content increased mainly in the dried blueberry macerates, which raised between 4 to 5.5-fold. More bioactive compounds were extracted from wines produced by yeast inoculation despite shorter maceration times. Sensory analysis demonstrated consumer acceptance of the wines in terms of color, flavor and aroma. In conclusion, the use of red grapes in the production of blueberry red wine proved to be effective, providing sugars and higher must yields, while the dried fruits improved the fermentable sugar content and the levels of bioactive compounds, increasing the antioxidant capacity of the resulting red fruit wines.