Mummification is a multi-stage preservation process that removes moisture from a body before bacteria can break down soft tissue. The ancient Egyptian method, the most well-documented version, took exactly 70 days from start to finish and involved organ removal, chemical drying, and meticulous wrapping with hundreds of yards of linen.
Removing the Brain
The process began with the brain. Embalmers inserted long hooked instruments up through the nostrils to pull out brain tissue in small pieces. The approach went through the thin bone of the nasal cavity, typically on the left side. Early practitioners broke through the ethmoid bone (the sieve-like plate between the nasal cavity and the skull), while later embalmers shifted to a route through the sphenoid bone deeper in the skull base. This is essentially the same anatomical pathway that modern neurosurgeons use to reach pituitary tumors, making it one of the oldest known surgical techniques still in use today.
Removing the Organs
Next, embalmers made an incision on the left side of the abdomen and removed the organs of the chest and abdominal cavity. The lungs, liver, stomach, and intestines were each cleaned and stored in their own canopic jar, protected by a specific deity: a human-headed god guarded the liver, a baboon-headed god watched over the lungs, a jackal-headed god protected the stomach, and a falcon-headed god kept the intestines.
The heart stayed in the body. Egyptians considered it the seat of intelligence and identity, essential for the afterlife. Everything else that could rot quickly was taken out.
Drying the Body With Natron
This was the critical step. Embalmers packed the body inside and out with natron, a naturally occurring mineral salt collected from dry lake beds. Natron is primarily sodium carbonate and sodium bicarbonate, with traces of chloride and sulfate salts. It works by aggressively pulling water out of tissue, essentially the same chemistry as table salt curing meat, but far more effective.
The drying phase consumed roughly the first 35 days of the 70-day process. Natron packets were stuffed inside the body cavity, and the exterior was buried in mounds of the mineral. The goal was total desiccation: removing enough water that bacteria and fungi couldn’t survive to decompose the flesh. Without this step, the body’s fat would convert into a waxy white substance called adipocere, a common outcome in moist burial environments. Natron prevented that by creating conditions too dry for the chemical reactions that produce it.
Once drying was complete, embalmers removed the internal natron packets and gently washed the salt residue off the skin.
Restoring a Lifelike Appearance
A dried body is shrunken and hollow. Embalmers packed the sunken areas with linen, sawdust, and other stuffing materials to restore a more natural shape. False eyes were inserted. The intent was to make the mummy recognizable as the person it had been, since Egyptians believed the soul needed to identify its own body in the afterlife.
Anointing With Oils and Resins
Before wrapping, the body was anointed with a mix of fragrant oils, animal fats, and tree resins in a religious ceremony. Frankincense, myrrh, cedar oil, ox fat, and pine resin all appear in the archaeological record. A 2023 analysis published in Nature identified specific mixtures of antiseptic oils, tars, and coniferous resins used at the burial site of Saqqara, revealing that substances ancient texts called “antiu” and “sefet” were actually complex blends of pine or fir tar mixed with plant-based unguents.
These resins weren’t just ceremonial. Pine and fir resins have genuine antimicrobial properties, creating a chemical barrier against the microorganisms that cause decay. The true resins came from trees in the eastern Mediterranean: Lebanese cedar, Cilician fir, and Aleppo pine. The gum-resins, likely myrrh, were imported from further afield.
The Wrapping Process
The second half of the 70-day period was devoted to wrapping and final rites. Each mummy required hundreds of yards of linen strips. Priests wound the bandages carefully, sometimes wrapping individual fingers and toes separately before covering the entire hand or foot.
The wrapping wasn’t a single continuous layer. Protective amulets were tucked between the strips, and prayers or magical spells were written directly on some of the linen. A portrait mask of the deceased was often placed over the face between layers of head bandages. At several points during the process, priests coated the partially wrapped form with warm liquid resin, let it set, and then continued wrapping over it. This created alternating layers of sealed resin and linen, essentially laminating the mummy against moisture and air.
After wrapping was complete, a second resinous liquid was poured over the finished mummy, and sometimes over the coffin and the canopic jars as well. A final linen shroud was placed over everything and secured with more strips. The mummy was done.
How Natural Mummification Works
Egypt’s embalmers were imitating a process that nature performs on its own under the right conditions. Natural mummification happens when a body dries out faster than bacteria can decompose it. The key environmental thresholds: daytime temperatures above 30°C (86°F), solar radiation above 600 watts per square meter, humidity below 50%, and steady wind between 32 and 48 kilometers per hour. Hot deserts, high mountain passes, and sun-exposed rocky terrain all meet these criteria.
Bog bodies represent a completely different preservation pathway. In waterlogged, oxygen-free, acidic peat bogs, the chemistry preserves skin and soft tissue while dissolving bone. This is essentially the opposite of desert mummification, where bone survives easily but soft tissue needs intervention.
Modern Mummification
Mummification isn’t exclusively ancient. Summum, an organization based in Salt Lake City, has performed modern mummification since the late 1970s. Their process echoes the Egyptian framework but uses contemporary chemistry.
The body is bathed and cleansed, and an incision is made to remove the organs. Unlike the Egyptian method, the organs are cleaned and placed back inside the body. The body is then submerged in a preservation solution for an extended period, allowing the chemicals to fully penetrate the tissue. After removal from the tank, the body is cleansed again, coated with a lotion, and wrapped in layers of cotton gauze.
From there, the process diverges sharply from ancient practice. A polyurethane membrane is sealed over the gauze, followed by a layer of fiberglass and resin. The finished mummy is placed inside a welded metal or bronze sarcophagus, which is then filled with amber resin that completely surrounds the body. The result is a permanent, airtight encasement designed to last indefinitely.