A certain charred material in a bowl was found in a tomb bulit during the early Warring States period(475-221BC) in Zoucheng, Shandong province. It seems like remnant after tea boiling or brewing Relevant research results have been published in the academic journal “Archaeology and Cultural Relics”, Issue 5, 2021 by a team from Shandong University.
The discovery is the testimony demonstrating the most immemorial tea residue (453-410 BC period) in the world, the article said.
Techniques, including Fourier transform
infrared spectroscopy (FTIR), Gas Chromatograph Mass Spectrometer (GC/MS) and
thermally assisted hydrolysis-methylation Pyrolysis Gas Chromatography Mass
Spectrometry (THM-Py-GC/MS) were used to scientifically analyze the residues,
with modern tea leaves and tea residue as reference samples.