Grapes, grains and genomes: The archaeogenetics of fermented beverages

The extraction and sequencing of DNA from artefacts and archaeobotanical remains have revolutionised the study of past diet and agricultural practices. Beyond reconstructing extinct genomes, ancient DNA provides insight into microbial communities, cultivation techniques and genetic networks in antiquity. This dissertation comprises three research studies on distinct materials: yeast rings, fermentation barrels and archaeological grape seeds, where I applied metagenomics and population genomics analyses to investigate traditional fermentation, viticulture and winemaking. After introducing the broad themes on ancient DNA, beer brewing, viticulture and winemaking in Chapter 1, Chapter 2 explores Norwegian farmhouse brewing through metagenomic analysis in historical yeast rings and fermentation barrels. This study highlights the potential of biomolecular research in reconstructing historical brewing methods and preserving microbial heritage. Chapter 3 examines ancient viticulture at Cetamura del Chianti, Italy, combining aDNA analysis with morphometrics, spectroscopy and radiocarbon dating to trace grape cultivation from the Etruscan to Roman periods. Limited genetic connections to modern varieties suggest many ancient cultivars may be extinct. In contrast, analysis of Roman-era grape seeds from Barbir harbour, Croatia, in Chapter 4 demonstrates extensive trade networks with genetic links to modern grape varieties.
Overall, this thesis highlights ancient DNA analysis as a powerful tool in understanding past fermentation and agricultural practices. By bridging archaeology, microbiology, and cultural heritage perspectives, it provides new insights into the persistence and evolution of fermentation traditions, offering both historical and commercial implications for brewing and viticulture today.