Must

Must is the juice of freshly pressed grapes, prior to fermentation into wine. Must contains various quantities of pulp, skins, stems, and seeds, called pomace or grape solids, which typically comprise between 7-23 percent of the total weight of the must. These components, and the time they are allowed to be in contact with the juice, are critical to the final character of the wine.

When the winemaker judges the time to be right, the juice is drained off the pomace which is then pressed to extract the juice retained by the matrix. Yeast is added to the juice to begin the fermentation, while the pomace is often returned to the vineyard to be used as fertilizer.

References

• Ron Herbst and Sharon Tyler Herbst; Wine Lover's Companion; Barron's; ISBN 0-8120-1479-0 (paperback, 1995)
• Marian W. Baldy, Ph.D.; The University Wine Course - A Wine Appreciation Text & Self Tutorial, 2nd Edition; The Wine Appreciation Guild; ISBN 0-932664-69-5 (paperback, 1995)