Recent excavations at HK11C Operation B at Hierakonpolis have revealed remains of pit-kilns dated to the Naqada II period, in which mainly straw-tempered modeled rim jars were produced. This discovery is valuable not only for the new data it presents for the study of Predynastic pottery, but also for providing an opportunity to reconsider ancient pottery production techniques. To evaluate the firing technique used in the HK11C kilns, an integrated analysis was conducted, which included ICP-AES, SEM, and in-depth observations of the surface stains on pottery from Hierakonpolis.

To asses firing temperature, SEM analysis was carried out on sherds from HK11C and locally collected clay samples, which cluster analysis of ICP-AES data suggests was the raw material used for pottery production at the site. The results allowed the firing temperature of straw-tempered jars to be estimated in a range from under 800ºC up to 1000ºC, the variation indicating that a bonfire kiln-type was used.

In-depth observation of stains on selected complete jars revealed the potential layout of the vessels in such a kiln, suggesting that they were placed on their side in a radial, flower-like arrangement and stacked in several layers. As the jars were well-fired and exhibited no fire stains, it may be proposed that the pots, once arranged in the kiln, were covered with a layer of sherds and mud forming an ad-hoc roof. This covering provided better firing conditions within the kiln and prevented fire staining. Although this covering does not remain in situ around the kilns in Operation B, sherds with burnt mud adhering to them have been found in abundance in the associated debris.

While the firing method proposed for these pit kilns may be classified with bonfire types, it is technologically more advanced, allowing for more reliable and economical results. The ancient potters in the Naqada II period may have enhanced their pyrotechnology in response to the social developments leading toward statehood.