Exploring grape pressing for sparkling wine production: A comprehensive literature review on physicochemical parameters and technological applications

The pre-fermentative steps play an important role on the characteristics of white wine. Among them, the grape pressing is a crucial phase as the extraction of grape compounds occurs having a relevant impact on the composition of must and, consequently, of wine. The grape pressing is particularly important for the sparkling wine production as it influences the acidity and phenol concentration of must.

The aim of this review was to explore the must changes occurring during grape pressing. The pressing technologies and conditions were discussed and compared, considering their impact on must composition. Special attention was devoted to the pressing of grape for obtaining must addressed to sparkling wine production, considering the challenges for preserving the acidity and managing the extraction of phenolic and aromatic compounds. Hence, the current awareness and the gaps of knowledge are presented and discussed.

Pressing grapes for white and sparkling winemaking requires a controlled approach to maintain must integrity and ensure the quality of the final product. High constraints on solid parts mean higher extraction of phenolics, aroma precursors and potassium. The latter, causing the precipitation of tartaric acid, leads to a pH increase and acidity decrease. Higher extraction of phenolics can make the must and the wine more susceptible to oxidation. Different conditions adopted in terms of grape temperature, oxygen exposure, applied pressure, fractioning and types of press affect the composition of must. Future researches on this step should also consider the grape composition.