Wine production with non-Saccharomyces yeasts is getting larger application due to the positive impact of these yeasts on wine composition. Previous studies showed notably differences in chemical composition of Merlot wines obtained with Torulaspora delbrueckii.

The use of stems during fermentation is generally avoided due to the herbaceous off-odors they can impart to the wine. [1].

Wines made with grapes submitted to postharvest dehydration are often referred to as “passito” or “straw wines.” This distinct style of winemaking consists of a process of water loss that allows the berries to undergo a mild water stress and senescence process [1].

During aging, wine consumes small amounts of oxygen. This oxygen intake triggers a series of reactions that lead to flavonoid elongation, which is known to reduce bitterness and astringency while enhancing color stability.

Polyphenols are common in human diets, primarily in plant-derived food and beverages. They influence multiple sensory properties such as aroma, flavour, colour, and taste, such as astringency and bitterness [1]. The major phenolic compounds in grapes and wines are anthocyanins and tannins (proanthocyanidins or condensed tannins).