Mashes to Mashes, Crust to Crust. Presenting a novel microstructural marker for malting in the archaeological record

PLoS One. 2020 May 7;15(5):e0231696. doi: 10.1371/journal.pone.0231696. eCollection 2020.

Abstract

The detection of direct archaeological remains of alcoholic beverages and their production is still a challenge to archaeological science, as most of the markers known up to now are either not durable or diagnostic enough to be used as secure proof. The current study addresses this question by experimental work reproducing the malting processes and subsequent charring of the resulting products under laboratory conditions in order to simulate their preservation (by charring) in archaeological contexts and to explore the preservation of microstructural alterations of the cereal grains. The experimentally germinated and charred grains showed clearly degraded (thinned) aleurone cell walls. The histological alterations of the cereal grains were observed and quantified using reflected light and scanning electron microscopy and supported using morphometric and statistical analyses. In order to verify the experimental observations of histological alterations, amorphous charred objects (ACO) containing cereal remains originating from five archaeological sites dating to the 4th millennium BCE were considered: two sites were archaeologically recognisable brewing installations from Predynastic Egypt, while the three broadly contemporary central European lakeshore settlements lack specific contexts for their cereal-based food remains. The aleurone cell wall thinning known from food technological research and observed in our own experimental material was indeed also recorded in the archaeological finds. The Egyptian materials derive from beer production with certainty, supported by ample contextual and artefactual data. The Neolithic lakeshore settlement finds currently represent the oldest traces of malting in central Europe, while a bowl-shaped bread-like object from Hornstaad-Hörnle possibly even points towards early beer production in central Europe. One major further implication of our study is that the cell wall breakdown in the grain's aleurone layer can be used as a general marker for malting processes with relevance to a wide range of charred archaeological finds of cereal products.

Publication types

  • Historical Article
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Archaeology / methods*
  • Beer / analysis
  • Beer / history*
  • Edible Grain* / chemistry
  • Edible Grain* / ultrastructure
  • Egypt
  • Europe
  • History, Ancient
  • Humans
  • Microscopy, Electron, Scanning
  • Plant Proteins / ultrastructure*
  • Seedlings / chemistry
  • Seedlings / ultrastructure

Substances

  • Plant Proteins
  • aleurone

Grants and funding

AGH, FA, HPS, MBA, SMV received funding from the European Research Council (ERC-CoG-2015, GA 682529) https://cordis.europa.eu/project/rcn/202606/ AGH, FA, NB received funding from the Cantonal Archaeology of Zürich http://www.are.zh.ch/internet/baudirektion/are/de/service/international.html EM received funding from the RBINS https://www.naturalsciences.be/ HK received funding from BRAXAR GmbH http://web.archive.org/web/20181108112716/http://brewmaltster.de/ HS received funding from the DFG (62215951) https://gepris.dfg.de/gepris/projekt/62215951 KMC, LKM, MC received funding from the NCN (UMO-2014/13/B/HS3/04976) https://projekty.ncn.gov.pl/index.php?s=7908 LKM received funding from BIAX Consult https://www.biax.nl/ MB received funding from the Japan Society for Promotion of Science (Grant-in-Aid for Scientific Re-search (C), 16K03167) https://kaken.nii.ac.jp/en/grant/kakenhi-project-16K03167/ Additional remarks: Experimental approaches and their evaluation were funded by the European Re-search Council within the framework of the project ‘PLANTCULT’: Identifying the Food Cultures of Ancient Europe, under the European Union’s Horizon 2020 Research and Innovation Program (Grant Agreement No. 682529, Consolidator Grant 2016-2021, PI Soultana Maria Valamoti). Archaeobotanical analysis of the Hierakonpolis material was financially supported by the unit “Quaternary Environ-ments and Humans” of the Royal Belgian Institute for Natural Sciences (RBINS), Brussels. Excavations at Hierakonpolis were undertaken under the auspices of the Hierakonpolis Expedition with funds provided by the Japan Society for Promotion of Science within the Grant-in-Aid for Scientific Research (C) programme (proj. no. 16K03167). The analysed materials from Tell el-Farkha were excavated in the 2017 campaign which was funded by the National Science Centre Poland (NCN) as part of the project “Sociopolitical transformations in the Eastern Nile Delta at the transition between the 4th/3rd millenni-um BC” (grant UMO-2014/13/B/HS3/04976) and which was additionally sponsored by the Jagiellonian University in Kraków, the Archaeological Museum in Poznań, the Polish Centre of Mediterranean Ar-chaeology, the University of Warsaw,and the Patrimonium Foundation, Poznań. The material from Hornstaad—Hörnle IA was unearthed during the 1983–1993 excavations which were funded by the DFG (Deutsche Forschungsgemeinschaft) within the framework of the DFG Schwerpunktprogramm „Siedlungsarchäologische Untersuchungen im Alpenvorland“ (PI: Dieter Planck). The finds from Sip-plingen—Osthafen were excavated within the scope of the project “Das ‘Sipplinger Dreieck‘ als Modell jung- und endneolithischer Siedlungs- und Wirtschaftsdynamik am Bodensee“ which was also funded by the DFG (proj. no. 62215951, PI: Helmut Schlichtherle). Excavations at Zürich Parkhaus—Opéra were funded by the Cantonal Archaeology of Zürich, the Office for Urbanism of the City of Zürich, and the Federal Office for Culture (FOC) Switzerland, as were the archaeobotanical analyses of fragment ZHOPE 6949.1, carried out at the Vienna Institute for Archaeological Science (VIAS) at the University of Vienna in 2014. The State Office for Cultural Heritage Baden-Württemberg and the Institute for Botany (210) of the University of Hohenheim funded the international workshop “Ancient beer: multidiscipli-nary approaches for its identification in the archaeological record” held at the University of Hohenheim in February 2019, during which the foundations for this paper were laid. The comparative find no. 252 from Haselbach was obtained from the project „Keltische Siedlungszentren in Ostösterreich“ (PI: Peter Trebsche and Stephan Fichtl) funded by the Federal Government of Lower Austria. Funders BIAX Consult and Braxar GmbH provided support in the form of salaries for authors LKM and HK, respectively, but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section. Neither had the other funders a role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.