What does the term 'must' refer to in winemaking?

The term 'must' in winemaking refers to the mixture resulting from crushing grapes, which includes not only the juice but also the skins, seeds, and sometimes stems. This combination is an essential part of the winemaking process, as it plays a critical role in flavor, color, and tannin extraction during fermentation. The skins contribute to the wine's color and aromatics, while the seeds can impart tannins, adding to the complexity of the wine.

In contrast, other options provide limited definitions that do not encompass the full scope of what must is. For example, fermented grape juice only describes the end product of fermentation without acknowledging the important components present before fermentation begins. Filtered grape juice also fails to represent the initial mixture used for fermentation, as must is untouched by filtration in its early stage. Lastly, grape seeds alone do not define must, as they are just one part of the mixture and do not provide a holistic view of the pre-fermentation ingredients. Thus, recognizing must as the inclusive blend of juice, skins, seeds, and stems is crucial for understanding the foundational element of winemaking.