Almost all the respected Roman wines were white and quite sweet. There are two well-known quotations:
"Be the first to dig the ground, first to bear away and fire the prunings, first to carry the poles under cover; be the last to reap." (Virgil, Georgics II.410)
"Corn is crammed in every corner and many a wine jar is fragrant with ancient vintages. Here, when November is past and winter soon to come, the rugged pruner brings home the tardy grapes." (Martial, Epigrams III.58)
The above quotations suggest Roman vintners left the harvesting of their crops till quite late in the season. The warmth of the Mediterranean climate then ensured the grapes then contained a lot of sugar—so much that, during fermentation, the alcohol content of wine probably reached about 12%.
Red wines take their color from pigments in the skin of a dark grape, but the best Roman wines were produced with those skins excluded from the fermentation process. Taverns may well have sold lesser quality red wines, however; and the wine ration of farm laborers and slaves, which was little more than a watered-down fermentation of grape-skin mash, will often have been red, as well.
There is occasional mention of better quality dark (niger or fuscus) Roman wines. But that description most likely referred to a honey-amber color, to contrast it with the pale yellow color (albus, or paler still, fulvus) of lesser vintages.
Though Roman wines were sweet to begin with, they often were sweetened even further by the addition of honey to the fermentation vat. This yielded mulsum, which was usually served with hors d'oeuvres, such as salted fish and stuffed artichokes, before an evening meal's main courses.
- Fleming, S.J., 2001: VINUM: The Story of Roman Wine, plates 28 and 29 (Glen Mills, PA: Art Flair).
- Fitton Brown, A.D., 1962: The Classical Review XII, 192-195.