Sauces and dressings

Romans typically mixed savoury and sweet foods. These were often served with meat, fish and wild birds, but in particular, one of the characteristics of the Romans’ diet was the extensive use of sauces served with each dish. It is believed that, as a result of the way it was prepared, food lost its original taste; for instance meat was cooked at least twice: the first time in milk and the second time either with vegetables or roasted; and in addition seasoning was heavily used (note that recipes never indicate the doses). 

The art of cooking consisted in knowing how to disguise not only the appearance of food, but also its taste (also because, there being no fridges, it was necessary to cover up the rancid taste of certain foods). A variety of sauces were made using ingredients which had little to do with the main food of the dish, such as, for example, fish or fruit sauces on meat recipes. One of the most popular sauces was the garum (from the Greek garon, the name of the species of fish used) or liquamen, a kind of mixture obtained by macerating fish entrails in salt with oil, wine, vinegar and pepper. Such a sauce would have a nauseating smell and taste for our standards, as various people of that time already believed, such as Martial. 
The garum industry in the Mediterranean was highly developed, and the best type was produced in Spain and was very expensive, whilst the most famous garum made in Italy was that produced in Pompeii. Other spices indispensable in the ancient Roman cuisine were saffron, pepper and ginger. 

The Romans prepared a variety of seasonings also out of vinegar, and used potato flour as binding agent for sauces. Olive oil was used not only as seasoning, but also for medicine and lighting, and different types were available. The average consumption of olive oil of a Roman citizen was approximately two litres per month. To get an idea, suffice it to mention that Monte Testaccio is made up essentially of empty oil amphorae, mainly from the Betica region (southern Spain), the largest exporter of olive oil of that time. Given the mild climate of the city, the Romans also became masters in the art of food preservation: by smoking (usually cheese), dehydrating (meat), spreading honey (on fresh fruits), or by salting.