Cooking Residues

One source of information about prehistoric cooking activities is charred residue adhering to the interior of pottery and steatite sherds. Other residues are absorbed into the fabric of pottery sherds. Both kinds of residue can provide information on some of the specific foods that were cooked in the vessels. The charred residues can yield phytoliths from plants (Hart et al.2003, 2007a; Hart and Matson 2009; Thompson et al. 2004), starches from plants, and lipids from both plants and animals (Hart et al. 2008; Reber and Hart 2008a, 2008b). Lipids are also absorbed into the fabric of pottery sherds. The phytoliths and starch grains may be identifiable to genus or species, while lipids may be identified to species or high-level taxonomic units. Experiments have recently shown that stable isotope analysis of charred cooking residues can be misleading (Hart et al. 2007b, 2009; Lovis et al 2011). In fact in order to interpret carbon isotope values from cooking residues it is necessary to know in advance what was actually cooked in the pot when the residue formed.

Chronological information can also be gained from charred cooking residues through accelerator mass spectrometry (AMS) dating. Concern has been raised as the the accuracy of AMS dating of carred residue because of the potential for old carbon to be introduced into residues by cooking aquatic organisms. Ancient cabon is often present in freshwater bodies and is incorporated into fish and shell fish flesh. Various lines of evidence have shown that this is apparently not a problem in portions of eastern North America including New York (Hart et al. 2013; Hart and Lovis 2007a, 2007b, 2014; Lovis and Hart 2015).

Analysis of over 90 AMS dates obtained on charred cooking residues has changed our perceptions of crop histories and of the chronologies of steative bowls and various prehistoric pottery types (Hart and Brumbach 2003, 2005; Hart and Lovis 2007; Hart et al. 2003, 2007; Tache and Hart 2013; Thompson et al. 2004), and has helped to clarify trends in pottery technology (Hart 2012; Hart and Brumbach 2009). This work has substantially rewritten the histories of maize, bean, and squash in New York (Hart 2008, 2016).