A team of archaeologists recreated one of the two bakeries found during excavations at the Lost City of the Pyramids, which show that bread was baked there using a typical Old Kingdom method. Bread dough was placed in ceramic moulds, which in turn were placed on a thick bed of hot ash and covered with a second pre-heated mould. Twenty-four mould indentations were found in each of the two bakeries. Modern experimental work has revealed that it takes 2.5 hours to mix and bake a single batch of 24 loaves. It is likely that four batches were made every day, adding up to a total of 10 hours of work. Each bakery unit could thus produce 100 loaves of bread a day, feeding 800 people!
For more, see Claire Malleson's article 'Feeding The Forces' from Rawi magazine's Issue 10 available online (link in details).