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Black drink is a native North American caffeinated tea produced from the leaves of Ilex vomitoria . The beverage was an important part of prehistoric Southeastern culture, as it was the only native source of caffeine in North America. The leaves of I. vomitoria were, therefore, a potentially valuable trade resource during the period. As such, the ability to identify archaeological black drink residues is useful to Southeastern archaeologists. In order to determine the plausibility of detecting I. vomitoria in residues, black drink was repeatedly produced in experimental unglazed pottery. The resulting potsherds were buried in several environmental contexts, recovered, and underwent absorbed pottery residue analysis. After two months of burial in three different soil types, plus a control stored in the freezer, caffeine was well-preserved in all sherds, suggesting that caffeine is a potentially useful biomarker for the detection of black drink.

Analysis was performed on absorbed and visible residues from 21 New York State prehistoric pottery sherds dating from 2905 ± 35 bp (Intcal04) (1256–998 cal bc) to 425 ± 40 bp (Intcal04) (1417–1626 cal ad). The use of pine resin was detected in 10 of 12 absorbed residue samples and 11 of 17 sherds subjected to visible residue analysis. It seems likely that the pots were resin-sealed to make them more impermeable, constituting the first chemical evidence of extensive resin-sealing in North America. A comparison of the results of absorbed and visible residues from eight of the sherds indicates that the two kinds of residue provide complementary evidence of vessel use.

Discovering what was cooked in a pot by identifying lipids trapped in the potsherds has been a highly successful method developed in recent years. Here the authors identify a compound which shows the pots had been used to process maize – probably the most important foodstuff in later prehistoric North America. The uptake of maize is confirmed as coincident with the Mississippian fluorescence.

The analysis of organic remains left on pottery, stone tools, or other archaeological artifacts is important because it shows how humans used artifacts. Residues can come in many forms. Visible residues can be seen on the surfaces of stone tools and pots, and can include microscopic remains, as well as biochemical clues. Absorbed residues have soaked into a pot wall and are invisible until destructively extracted. A variety of archaeometric techniques may be used on organic residues, depending on the type of residue and the sort of information being sought by the analyst. Chemical components of residues have generally undergone some sort of degradation through time and environmental effects, and interpretation of chemical residues must take this into account. In general, a combination of analysis types is most effective, if it is possible to do this.