Grape Must

What is grape must?

Grape must is the freshly pressed juice of grapes that retains all solid components including skins, seeds, and stems, representing the crucial first stage of winemaking before fermentation begins. This unfermented mixture typically contains 18-25% sugar content (measured in Brix), which will later convert to alcohol during fermentation. The composition of must varies significantly based on grape variety, ripeness level, and pressing technique. White wine production often involves immediate separation of juice from solids, while red wine must undergoes extended contact with skins to extract color, tannins, and flavor compounds. The must’s pH levels typically range from 3.0-4.0, with higher acidity in cooler climates like Argentina’s high-altitude regions. During the brief must stage, winemakers may adjust sugar levels through chaptalization or acidity through acidulation, though Argentine regulations strictly control such practices. The temperature of fresh must usually ranges from 15-20°C, and immediate handling is critical to prevent unwanted oxidation or wild fermentation. Quality assessment of must through laboratory analysis determines the wine’s potential, making this stage fundamental to successful winemaking across Argentina’s diverse terroirs.

For the point where white, rosé, red, and skin-contact routes diverge, follow the branching guide to how wine is made.