Acorn Oil Rendering in the Upper Great Lakes

Summary

Recent research in the Upper Great Lakes region has demonstrated the importance of acorns as a dietary staple. As a plentiful and easily storable source of carbohydrates and fats, acorns provide an excellent dietary complement. Organic residue analysis of pottery sherds and fire-cracked rock from Grand Island, Michigan yielded lipid profiles consistent with nut oil, suggesting that the vessels may have been used to process acorns through boiling or simmering. In order to make many species of acorns palatable, regionally-specific methods for removing harmful tannic acid are documented throughout North America. Because tannic acid is water soluble, rendering oil from acorns through boiling may have been an effective means of producing a storable, high-fat product free of tannins. While ethnohistoric descriptions of rendering oil from acorns exist, the mechanics and archaeological signatures remain poorly understood. In order to evaluate the hypothesis that ceramic vessels were a crucial component of nut oil rendering, we test a variety of techniques to render acorn oil. The results of these experiments will not only inform the rationale behind changing cooking technologies in the Upper Great Lakes, but may also provide a means for identifying alternative acorn-derived products in the archaeological record.

This Resource is Part of the Following Collections

• Society for American Archaeology 82nd Annual Meeting, Vancouver, BC (2017)

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Record Identifiers

Abstract Id(s): 17031