Profit Margins

To be marginally profitable, the entrepreneurial vintner had to produce at least 35 amphorae of wine per acre; then he had to sell his wine at about 25 sestertii per amphora. If, however, the weather was kind and the vinitor skilled, far higher yields were possible, maybe three times above average, and the venture's income would soar. An investment return of more than 20% was possible, a figure well ahead of the standard Roman interest rate of 6% he might glean from straight money-lending.

"Pressing the Grapes"
Detail from a 15th century fresco at Trento, in northeastern Italy