By Eben van Tonder, 4 April 25

Indroduction

Venice is a city that should not exist, at least not by conventional engineering standards. Built in the early 5th century by refugees fleeing barbarian invasions, it rose from the lagoon not on solid rock but on millions of tree trunks driven vertically into mud and silt. As Michael Parker recently shared in a post that captured the imagination of many, including myself, Venice was not built on solid ground, but on timber submerged in seawater and sealed in mud, forming an environment where rot could not easily occur.

The wood, mostly alder, elm, and oak, did not decay. Instead, the anaerobic, mineral-rich, and saline conditions of the lagoon preserved it, hardening it over centuries until it became structurally stable enough to hold up basilicas, towers, and homes. The Basilica della Salute alone sits on more than one million wooden pilings, each driven by hand to a depth of nearly three metres. The entire city rests on this engineering miracle, a quiet triumph of pre-modern science.

This principle of anaerobic and mineral preservation, however, is not limited to timber. In my own research into historical meat preservation, particularly through the Hallstatt curing traditions and African fermentation methods, I have explored the similarities between how Venice’s foundations were preserved and how ancient societies preserved meat by burying it in clay pits with salt.

Mechanistic Parallels Between Venetian Timber and Clay Buried Meat

1. Anaerobic Environment In both cases, oxygen is excluded. Venice’s wooden foundations are submerged in water and covered by silt and clay, drastically limiting oxygen exposure. Similarly, ancient methods of burying meat in clay pits involved sealing it with wet clay, preventing oxygen ingress. This effectively inhibited aerobic bacteria such as Pseudomonas and Micrococcus, which are primary contributors to spoilage.
2. Salt Saturation and Microbial Inhibition In Venice, the surrounding saltwater diffused into the wood, increasing the ionic environment and suppressing microbial activity. Likewise, when meat is buried in salt enriched clay, the high salinity reduces water activity (a_w) and creates an environment hostile to most spoilage organisms. The presence of salt also stabilises proteins and can inhibit proteolytic enzyme activity.
3. Temperature and Moisture Control Venetian timbers are maintained in a consistent, cool, and wet environment. This slows microbial and enzymatic action. Similarly, clay pits, especially those buried in shaded, subterranean areas, maintain stable temperatures and moisture, which help preserve meat and delay lipid oxidation and protein denaturation.
4. Mineral Interaction and Structural Effects Minerals from sediment, including calcium and iron, are slowly absorbed into submerged wood, contributing to its long-term hardness and resistance to biological degradation. In meat preservation, mineral-rich clay can interact with the meat’s surface, promoting the formation of protective crusts and possibly inhibiting bacterial metabolism through ion exchange.

Biochemical Progression in Salt Clay Meat Preservation

In Hallstatt-style curing and my own trials with fermentation in clay pits (van Tonder, 2023), several key biochemical mechanisms are observed:

1. Surface Dehydration and Water Activity Reduction Salt draws water from the surface of the meat via osmosis, creating a gradient that slowly dehydrates the tissue. This limits microbial growth by lowering the a_w value, a critical parameter in preservation.
2. Autolysis Under Controlled Conditions Even in anaerobic conditions, autolytic enzymes like cathepsins and calpains break down muscle proteins. However, the absence of putrefactive bacteria prevents these breakdown products from turning rancid. Instead, flavour-enhancing peptides and amino acids accumulate.
3. Fat Oxidation Delay and Saturation Effects In the absence of oxygen, lipid oxidation is significantly reduced. If the clay contains certain metal ions such as calcium or magnesium, they may also help stabilise phospholipids and prevent rancidity.
4. Bacterial Deamination and Ammonia Formation Over time, anaerobic fermentative bacteria such as Lactobacillus spp. and Clostridium sporogenes may contribute to mild proteolysis and deamination. This can lead to localised ammonia production, which may help shift pH and further inhibit spoilage organisms, a mechanism observed in ancient urinal or lime based curing as well (van Tonder, 2023).
5. Formation of Natural Protective Rinds Repeated burial, rinsing, and re-burial as observed in my curing experiments with clay (van Tonder, 2023) resulted in the formation of surface layers that hardened over time, similar to the ‘rind’ in traditional long cured hams. This rind both physically protects the meat and alters the local environment to limit microbial infiltration.

Historical and Cultural Parallels: Hallstatt and Beyond

At Hallstatt, archaeological evidence indicates long-term storage and curing of meat in salt-rich alpine caves. The similarity to Venetian wood preservation is striking, a stable, salt-saturated, low-oxygen, mineral-rich environment maintaining organic material for centuries. In our recent experiments in Cape Town, we noted that ammonia levels rose in buried meat under clay-lime matrices only after a threshold period, suggesting that slow microbial and chemical transformation played a key role (van Tonder, 2023).

These findings echo practices not only in Austria but in parts of Africa, China, and Central Asia, where meat or hides were buried in pits to control fermentation, odour, texture, and safety. The underlying principles, anaerobiosis, salt, mineral interaction, and microbial ecology, are ancient but strikingly coherent with the mechanisms that preserved Venice.

Venice, then, is more than a marvel of urban engineering. It serves as a living laboratory of preservation science, one that, when read carefully, helps us interpret the rationality behind seemingly rudimentary ancient food preservation practices.

References

Parker, M. (2025). Venice was not built on solid ground. [Facebook post]. Retrieved from https://www.facebook.com/share/12Gzakw9MRb/

van Tonder, E. (2023). Fermentation Trials in Clay: Ancient Curing Techniques Revisited. EarthwormExpress. Retrieved from https://www.earthwormexpress.com/

van Tonder, E. (2023). Reconstructing the Hallstatt Method: Ammonia, Clay and the Role of Microbial Ecology in Ancient Meat Curing. EarthwormExpress.

Zhou, G. H., Xu, X. L., & Liu, Y. (2010). Preservation technologies for fresh meat – A review. Meat Science, 86(1), 119–128.

Toldrá, F., & Reig, M. (2011). Innovations for healthier processed meats. Trends in Food Science & Technology, 22(9), 517–522.

Lücke, F. K. (2000). Utilisation of microbes to process and preserve meat. Meat Science, 56(2), 105–115.

Pikul, J., & Kummerow, F. A. (1990). Antioxidative activity of calcium and magnesium ions in meat. Journal of Food Science, 55(5), 1391–1393.

Schweizerisches Nationalmuseum. (2021). Hallstatt: Salzkammergut und das prähistorische Fleisch. Zurich: SNM Publications.