Secrets of Egyptian mummy making: A major breakthrough

Scientists have uncovered an ancient embalming facility in Egypt, an unprecedented discovery offering deep insight into the complicated process of how mummies were made and into Egyptian hieroglyphs.

Located around 30 kilometers (18.6 miles) south of Cairo, the facility dates to around 664-525 BC and consists of an aboveground structure and several underground rooms up to 30 meters (98.4 feet) below ground.

The substances found inside were sourced from as far away as Southeast Asia, highlighting an extensive trade network required for the embalming process.

A hidden recipe

Until now, scientists have gotten the bulk of their information about the mummification process from old papyri texts, Greek historians and the Egyptian mummies themselves. 

These sources indicated embalming was a complex process involving different mixtures of special oils, resins and tars.

However, although scientists were able to loosely pinpoint why and where some of these substances were used for embalming, they couldn't make these distinctions for all the ingredients. The old texts offered names of ingredients, yes, but translating ancient substance-related terms is challenging. So there's still debate on which exact substances some names refer to.

And although they could analyze the substances found in ancient mummies, researchers often couldn't pinpoint where, why or how they were used.

In a new study published on Wednesday in the journal Nature, authors found and analyzed exactly what researchers have needed to fill these knowledge gaps — 31 labeled ceramic containers, still full of residue, from a 600 BC embalming workshop. Some even contained instructions on how and where to use the specific substances.

For example: One container noted that the substance should be used for embalming of the head. Another instructed the embalmers to use the substance for a "pleasant" odor.

"Before this [study] we had, you know, names of things, but we never really knew what they were and we assumed they were something or the other," Salima Ikram, a professor of Egyptology at the American University in Cairo, told DW. She was not involved in the research that led to the results published in Nature.

More information about Egyptian language

Conducted in Saqqara, a massive ancient necropolis, the study brought archeologists, ancient language experts and chemists together.

"We [classified the ingredients] by identifying the chemical substances inside the vessel and correlating it with the label outside," co-author Philipp Stockhammer, a professor of archeology at the Ludwig Maximilian University of Munich, Germany, said in a press briefing.

These correlations allowed the researchers to challenge previous understandings of ancient Egyptian terms like "antiu", which is traditionally associated with myrrh, and "sefet”, traditionally described as an unidentified oil.

Here researchers found that "antiu" was not myrrh but rather a mixture of coniferous oils mixed with animal fat — an unguent — and that "sefet" was also a scented unguent containing plant additives like cypress oil or elemi.

The scientists also found tropical resins like elemi, which could come from as far as Southeast Asia or the African rainforests, and dammar, also from Southeast Asia. Both are known for their pleasant scents and antibacterial and antifungal properties.

"That shows us that basically the industry of embalming was a momentum driving early globalization forward, because it meant that you really needed to transport these resins over large distances from across Southeast Asia," said Stockhammer.

An Egypt-Europe collaboration

The recovered ceramic containers needed to be prepared and analyzed, but Egyptian law doesn't allow researchers to remove ancient samples from the country.

So the scientists collaborated with the National Research Center in Cairo, a local research and development center, to analyze the samples in Egypt. A lack of this sort of collaboration is the reason why previous research of this kind hasn't been possible until now, co-author Susan Beck said in a press conference.

Analyzing the substances

To analyze the samples, researchers powdered the ceramic vessels and extracted the embalming ingredients with solvents. Then, they analyzed them with a process called gas chromatography-mass spectrometry. 

"Think of it in terms of a chemical fingerprint of the recipe and then each ingredient also having its own chemical fingerprint," said co-author Stephen Buckley, an archaeology professor at York University and Eberhard Karls University in Tübingen.

Basically, the process separates the compounds and then finds the molecular fingerprint of the individual elements — which ultimately, Buckley said, allowed the researchers to identify the original embalming recipe.

Edited by: Clare Roth