Raw material
Raw material in winemaking refers primarily to the grapes that form the basis of wine, but may also include additional substances used to adjust or supplement the must during vinification. Grapes provide the fermentable sugars, organic acids, water and phenolic compounds that collectively determine the balance, flavour and structure of the finished product.[1]
Background
The centrality of grapes as the raw material for wine has been recognised since antiquity. While other fruits can be fermented into alcoholic beverages, the composition of grapes makes them uniquely suited to consistent and stable winemaking.[2] Traditional practices emphasised the natural qualities of the harvested fruit, whereas modern viticulture and oenology employ more precise methods to evaluate and refine raw material before fermentation.
Characteristics
The principal components of grape raw material include sugars (primarily glucose and fructose), organic acids (tartaric and malic), water, minerals, and a range of phenolic compounds such as tannins and anthocyanins.[3] These elements vary with grape variety, climate, soil, and viticultural technique. The maturity of grapes at harvest influences the eventual alcohol level, acidity, aroma profile and ageing potential of the wine. For this reason, vineyard monitoring and ripeness assessment are critical stages in determining raw material quality.
Use in winemaking
During vinification, the composition of raw material dictates the direction of fermentation and stylistic outcome. High sugar levels encourage higher alcohol content, while balanced acidity is essential for freshness and stability.[4] Phenolic compounds contribute colour, tannic structure and ageing capacity, particularly in red wines.
Secondary raw materials may also be introduced: selected yeasts initiate or guide fermentation; oak and other sources of tannin modify flavour; and fining agents adjust clarity and stability. In modern oenology, chemical analysis of raw material is routinely undertaken to measure sugar content (°Brix), acidity and nitrogen levels, enabling winemakers to tailor fermentation conditions for desired styles.[5]
See also
References
- ↑ Robinson (ed.), The Oxford Companion to Wine, Oxford University Press, 2015, ISBN 978-0198705383.
- ↑ Peynaud, Knowing and Making Wine, Wiley, 1984, ISBN 978-0471881491.
- ↑ Jackson, Wine Science: Principles and Applications, 5th ed., Academic Press, 2020, ISBN 978-0128161180.
- ↑ Boulton, Singleton, Bisson & Kunkee, Principles and Practices of Winemaking, Springer, 1999, ISBN 978-0834217011.
- ↑ Iland, Bruer, Edwards, Weeks & Wilkes, Chemical Analysis of Grapes and Wine, Patrick Iland Wine Promotions, 2004, ISBN 978-0958160515.