In the Early years of the Roman Republic the tasks of milling and baking were separate occupation. The milling of grain into flour was originally a household occupation. Saddle querns were used -- grain was placed on a flat quernstone and was crushed by rubbing another stone backward and forward over the top.. In the early 2nd century BC rotary querns were developed. These rotary hand querns remained in common use, and consisted of an upper concave stone, and a lower concave one. By the sixth century BC baking was being done commercially, and by the second
century B.C. milling and baking of grains was increasingly merged together as a single occupation. The diet of most of the Roman population was extremely frugal based on corn (grain), oil, and wine. Cereals mainly wheat, provided the staple food. Originally husked wheat ("far") was prepared as porridge ("puls") but later on naked species of what (eventually known as "frumentum")
were cultivated and made into bread. Brad was sometimes flavored with other foods such as honey or cheese, and was eaten at most meals (1). Pliny the El;der states that Picentine bread (made by those living in
Picentine, in eastern Italy) was made from spelt grits, that were initially soaked for some days and then mixed with raisin juice to form a dough. This was then baked in oven pots that broke during the heating.
Galen (d.A.D.i99) especially recommended that bread baked in large ovens as being the most digestible and tasty. The richer members of society had a range of breads, some prepared with milk, eggs, suet, honey or cheese, as well as sweeter cakes and pastries. The poorer members of the
community were more likely to have eaten coarse high-fibre bread, as well as grain pastes, and possibly millet porridge. Salt was not always used in bread making.

By this time the entire production of bread from milling the grain to whole loaves was a major industry. The larger rotary grain mills (donkey mills) in the later empire (Pompeii) were hour glassed shaped hollowed mills set upon closely fitted bell-shaped cone and turned usually with animal power.

Also water mills for milling grain were developed from the 1st Century B.C. and were capable of milling much larger quantities of grain

The unleavened bread of the early years was now joined by leavened bread for those who could afford it. This new burst of industry demanded some organization for the quantities of grain needed, the production of flour, and the increasing variety of bread and grain products.

It was determined in this period that bread which was prepared from wheat flour which was refined was far better for you than bread prepared from whole meal grains and which was unsieved. Wheat was the much preferred grain. Barley was considered to be much inferior, and much less
digestible or nourishing for the consumer.

Considering that the wheat supply coming into to Rome on an annual basis was at least 150,000 metric tons (1), and considering that this wheat was towed from Ostia up the Tiber canal to Rome, and the huge granaries of Rome were filled by human porters, the idea of organization becomes much more meaningful.

Milling and baking was often done also on the same premises, and for the most part remained a small scaled local occupation usually carried out by the bakers. In rural areas baking was a household task, but in towns of population there were bakers who provided bread, and also pastries and confections.

1. Adkins and Adkins, "Handbook To Life In Ancient Rome,"Oxford University Press, New York, 1984, Page 327, 342
2. Michael Grant, Rachel Kitzinger,Eds. "Civilization of the Ancient Mediterranean -- Greece and Rome, Vol. II, Keith Hopkins, "Roman Trade and Labor, "Charles Scribner's Sons, New York, 1988, Page 766 (ISBN 0-684-18865-1 -- Vol. II)
3. Don. R. Brothwell, "Foodstuffs, Cooking, and Drugs," Vol. I, Page 247.