Tonight on Channel 4 viewers can see former Torquay taxi driver Alan Billis become the 21st-century’s first human mummy.

Billis donated his body to the rather unusual project after discovering he had terminal cancer. It's an intriguing human story - and the science behind it is equally fascinating.

Mummifying Alan: Egypt’s Last Secret follows a team led by archaeological chemist Dr Stephen Buckley as they attempt to re-create the unique practices of the Ancient Egyptians of the 18th dynasty, the most highly skilled mummy-makers in history.

Dr Buckley gave us his step-by-step guide to making a modern-day mummy...

Prior to mummification

In Ancient Egypt the mummification process did not begin until four days after the subject had died. A short-term embalming process using palm wine (or, in the case of Alan, a 12 per cent alcohol solution) helped preserve the body while the deceased – most likely a member of the royal family – lay in state.

Organ removal

On the fourth day, Alan’s internal organs were removed, extracted by hand [by forensic scientist Prof Peter Vanezis] via a single four-inch incision. The heart, believed by the Ancient Egyptians to be the repository of intelligence, was left intact, a requirement for a soul to enter the afterlife.

Traditionally, the person responsible for making the incision was seen as having defiled the body and was symbolically chased away, with stones hurled after him. But Buckley was quick to point out that the team working on Alan had stopped short of this level of accuracy: “We didn’t throw stones at Peter - that would have been a bit harsh…”

Along with his heart, Alan's brain was also left intact, in line with the practices of the 18th dynasty. In earlier periods, where dry salt treatments were used, the brain would have been removed, but the salt water solution was able to preserve it intact, meaning removal was not necessary.

A mystery still surrounds the practice, however. “During the later part of the 18th dynasty, the males had their brains removed but the females did not,” says Dr Buckley. “That is a gender difference that is absolute – but we are still perplexed as to why. For some reason the females need their brains [in the afterlife] and the men don’t…”

Sterilising and packing the body

The body cavity was washed out with the antibacterial solution of alcohol and pine resin. Linen packets filled with sawdust, myrrh and spices were placed inside the body to maintain the shape of the abdomen. The incision was then sewn back up.

The protective coating

Next, the body would be given a protective coating – sometimes of beeswax, sometimes of gold. TV budgets being limited, Alan got beeswax. 

In the time of the Egyptians, the warmed wax would have been painted on with brushes by highly skilled practitioners. The only way Buckley and his novice mummy-makers could match the finish achieved by their ancient counterparts was to spray the wax on. The coating was then left to set. As well as protecting the body, it served to disguise the incision through which the organs had been extracted.

The natron bath

The Ancient Egyptian mummification process used the naturally occurring salt compound natron to preserve the body. But where previous generations of mummy-makers had used dry salts, 18th-dynasty practitioners dissolved the natron in water and submerged their subjects in the resulting solution. This was the stage of the process Dr Buckley was most keen to re-create.

Alan’s body was carefully lowered into a container filled with the natron salt water solution. Through osmosis, the salts would enter the soft tissue and slowly transform it into a substance more resistant to decay.

The Egyptians believed the stomach, intestines, liver and lungs were also needed after death. In those days they were preserved separately in their own “canopic jars”, each watched over by a different god. Alan’s extracted organs were treated in a similar way, placed in separate containers filled with the natron solution.

Alan’s body remained submerged in the solution for 35 days - but not without a struggle. “If you think about the Dead Sea, where you can float while reading a book…” says Buckley, “Well, the body wants to get to the surface.”  Alan’s was no exception.

“It was key that his body remain submerged. As soon as any part of it rose above the surface, you would immediately begin to get oxidation, which causes darkening of the skin.”

Initially, the body was tied down with linen cords. However, the pressure from the ties began to bleach the areas of skin where they were attached to the wrists and ankles. Finally, Buckley and co hit upon the idea of using sandbags to hold the body down - and in so doing Buckley believes they may have solved one of the mysteries of the Egyptian pyramids.

“In Tutankhamun’s tomb they found these sausage-shaped linen structures, but we’ve never been sure what they were for. It now seems likely that they were used for a similar purpose to our sandbags. They were the best way to keep the body submerged with minimal damage to the skin.”

Drying and wrapping

Once removed from the natron bath, Alan’s body was stored in a sealed environment that matched the dry heat of the Egyptian climate. After two weeks, the body had lost much of the residual water and was ready to be wrapped in the linen bandages most of us associate with the mummies of Hammer Horror and Halloween costumes.

Linen strips were cut to fit the various parts of the body and each layer sealed with softened beeswax and pine resin. The body was then left to dry for a further six weeks, during which time Dr Buckley and his team made various x-rays and scans that revealed that the preservation was going according to plan.

The wrapping stage would have been the last time the Ancient Egyptian embalmers laid eyes on their subject. But, three months after beginning the painstaking process of mummifying Alan, Buckley and co removed the bandages from his face to see how successful they had been.

“The idea of mummification for the Egyptians was that the soul would be able to recognise the body when it visited it from the afterlife," says Buckley. "When we looked at Alan after 90 days, it was definitely him.”

Tonight, that’s something viewers will be able to judge for themselves - tune in to Channel 4 at 9pm.