There are several different styles of Romano, all of which take their name from the city of Rome. Probably the best known is the sharp, tangy Pecorino Romano, made with sheep's milk. Caprino Romano is an extremely sharp goat's-milk version, Vacchino Romano a very mild cow's-milk cheese. Most U.S. Romanos are made of cow's milk or a combination of cow's milk and goat's or sheep's milk. Cheese lovers normally favor the sheep's- and goat's-milk versions, which have sharper, tangier, more pronounced flavors than the milder cow's-milk versions. In general, the pale yellow Romano is very firm and mostly used for grating.
From The Food Lover's Companion, Fourth edition by Sharon Tyler Herbst and Ron Herbst. Copyright © 2007, 2001, 1995, 1990 by Barron's Educational Series, Inc.