Fornax is the Roman Goddess of ovens, especially those used in a ritual context. Her name means just that—‘Oven’ or ‘Furnace’—and She presided over the Fornacalia, or Festival of Ovens. Her worship, or at least Her holiday, was said to date back to Numa, the legendary second King of Rome believed to have established many of the cultural, political, and religious institutions of Rome. She is closely associated with Vesta, the Roman hearth and fire Goddess, and the Vestal Virgins (the special priestesses of Vesta), were responsible for making the mola salsa, or ‘salted meal’ used in sacrifices, with grain toasted in the ovens of Fornax.

The mola salsa was made with far, in modern terms either spelt or emmer wheat grains. These were considered ‘primitive’ foods by the Romans and so reflecting an especially ancient, and so sacred, tradition. The grains were soaked in water, then toasted and ground with salt; the resulting meal could be left as a course flour, or baked into thin cakes. If made into cakes, one might assume that the water used was from the Fons Camenarum, the Fountain of the Camenae, known for its especially pure waters and long sacred to the Vestals. Either way the mola salsa played a very important part in official sacrifices: it could be used to purify the animal victim, being either sprinkled or crumbled over its head, or sprinkled over the fire of an altar. It was also used in private rites, for example as an offering at the central hearth of a household.

At the Fornacalia in February, the grain for the mola salsa was toasted, with Fornax charged with making sure the grain was perfectly toasted and not burnt; these toasted grains were then used by the Vestal Virgins to make the mola salsa at the Vestalia of June 7th through 15th. The mola salsa was considered especially pure, through its association with the Vestals, because it had passed through both pure water and fire, and because salt purifies and preserves.

The Fornacalia was a moveable feast of several days, probably starting around the 5th but always ending on the 17th of February, which was the Quirinalia, or festival of Quirinus, an early war God eventually said to be the deified Romulus. Each of the curiae (the ancient tribal divisions of Roman patricians) was assigned a day to lead the festivities, which were held in the Forum. Any one who missed the festival was considered stulti, or stupid, since they apparently didn’t know what curia they belonged to, and were supposed to make an offering on the 17th, called the Stultorum Feriae, or Feast of Fools. In this way, every family in Rome, or at least every family from the patrician class, participated.

Fornax Herself may have been invented later to explain the ancient festival, in effect being the personification of the oven and its heat. According to Ovid in his Fasti (‘The Calendar’, or a list of festivals, published in 8CE), ovens were originally used only for toasting grain, and so the process was the concern of Fornax, while hearths were where bread was baked, and so baking was under Vesta’s authority. In time though, of course, ovens were used for baking bread on a commercial scale (such ovens, with the very very very burnt bread still in them, have been found at Pompeii).

(And yes, ‘Fornacalia’ and ‘Fornax’ are related to the English word ‘fornicate’, through a complicated path involving mounded or arched ovens, the vaulted chambers of brothels, or arched porticos where prostitutes plied their trade.)

In time, Fornax was assimilated to Vesta, just as ovens, not just hearths, came to be used for baking bread, though in Ovid’s day they were considered separate Goddesses. In modern times, Fornax is assumed to be the Goddess of baking and bakers, and of the grain used in making bread, or the ripening of that grain (though the grain harvest is not in February in Italy); perhaps She was considered so, after merging with Vesta. But in earlier times Her realm was much more specific, and connected with the old, foundational, most holy rites of Rome.