Why Tyrian Purple Dye Is So Expensive
Narrator: Making authentic Tyrian purple dye starts here, with extracting a murex snail gland. It takes nearly 45 kilograms of these snails to produce a single gram of pure Tyrian purple extract. It’s a painstaking and pungent process. And the result? This single gram of dye that can fetch nearly $3,000. By comparison, 5 grams of a synthetic version sells for under $4.
Tyrian purple can be used to dye clothes or create paints. In the ancient world, it was so rare that only royalty could afford to wear clothes dyed with it. Even today, at such an astronomical price, Tyrian purple pigment is mostly a collector’s item. So, what makes real Tyrian purple so hard to make? And why is it so expensive?
This is Mohamed Ghassen Nouira. He’s been making Tyrian purple dye in his home in Tunisia for 15 years. Today, Ghassen is one of a handful of producers in the world bringing this ancient dye back to life. Ghassen learned how to make this dye through an excruciating process of trial and error. Because there’s no instruction manual, he reconstructed the techniques he uses from first-century texts.
Mohamed Ghassen Nouira: Oh, my God, I must say that I…I have gone through a lot of failures. The historical texts about the process of making Tyrian purple are very rare and are quite vague, so you have to start everything from scratch and learn everything on your own.
Narrator: To make the extract, Ghassen must navigate a complex process, and it’s this extensive labor that accounts for much of the final price. The part of the murex snail that contains the pigment is called the hypobranchial gland.
Mohamed Ghassen Nouira: The good thing is that the gland is located right under the shell, which helps a little bit in the extraction.
Narrator: It’s the only part of the snail used to make Tyrian purple, and each gland contains only a few drops of pigment. But before he can extract the gland, Ghassen has to wash, scrub, and sort the snails by size.
Mohamed Ghassen Nouira: You don’t really want all of this mud and scent to interfere with the dye when you crush the shell and expose the gland. So, this is the first step, and it’s a very important step. You really have to clean your snails very, very well.
Narrator: Ghassen can now extract the gland from the clean snails. If he hammers each shell too lightly, it’ll take too long. But if he hits it too hard, he’ll crush the gland. It took Ghassen two years to learn how to do this efficiently.
Mohamed Ghassen Nouira: And, of course, the snail is not wasted. Then it will be cooked for dinner. Everything is basically recycled.
Narrator: To make the extract, Ghassen first macerates the fresh glands in cold water and lets them ferment in an airtight container. Once the glands release their colorant, Ghassen gently washes and filters the mixture to separate the dye from the flesh. This is the first of six separate rounds of purification necessary to make a pure Tyrian purple extract.
Now Ghassen can dry the pigment mixture. He applies it to a sheet of glass and lets it dry under the sun. He uses glass because it won’t absorb any of the valuable pigment.
Mohamed Ghassen Nouira: So these glands have been drying for three days. They are half dry now. They’re still malleable, as you can say. This is the pure colorant, or, more or less pure.
Narrator: Once the pure colorant mixture is dried, he scrapes it off the glass with a razor, making sure to get every last bit.
Mohamed Ghassen Nouira: And the whole process, from the liquid colorant up until the dried pure powder, the whole mass will have lost at least 98% of its weight.
Narrator: The dried pigment is now purified five more times in a grinding-and-sieving process to remove any detritus. The nearly 100 pounds of murex snails are finally transformed into 1 gram of pure Tyrian purple extract. And acquiring enough snails is another challenge – an expensive one. Ghassen can spend hundreds of dollars sourcing the snails he needs for his dye. That’s because finding these snails requires experienced fishers.
One of the fishers Ghassen works with is Slim Ben Miled. He harvests murex snails from Soliman Beach. Like Ghassen, Slim and his team have perfected their technique over time.
Slim Ben Miled: It’s very hard to pinpoint a snail’s location underwater. Even though the sea is huge, we took the risks and learned how to find the location of snails. The snail likes rocks, a very specific type of rock found underwater.
Narrator: It can take Slim four hours to find the right snails, or he can dive for a whole day to no avail.
Slim Ben Miled: The most important thing for a good catch is good weather and a calm sea. Then the water will be clear for us to see snails. Otherwise, we will go home empty-handed.
Narrator: The blood-mouth snail is particularly difficult to catch and requires Slim to dive 15 meters deep, which makes it more expensive. And if the weather is consistently bad, the price goes up even more. Sometimes, conditions force Slim and his team to go a whole month without fishing. But it’s out of their control.
Slim Ben Miled: As sailors, we learned to be patient with bad weather conditions, because we can’t put ourselves in danger.
Narrator: It’s dangerous for the snails too, which are highly sensitive to climate change. Since the early 1970s, the population of murex snails has steeply declined due to temperature changes in the water and overharvesting.
Mohamed Ghassen Nouira: We have to be very cautious not to be engaged in overharvesting, to make sure that the small specimens are put back into the sea to preserve the species. So this is why it takes a lot of time.
Narrator: And careful management of the snail population is vital as Ghassen and his divers attempt to revive Tunisia’s thousands-year-old dye-making tradition.
Ghassen doesn’t use all the fresh snails to make extract. He reserves some to dye fabric directly. This time, he mixes the snail glands with water and a reducing agent and lets them ferment. The mixture goes from a colorless liquid to green before it turns purple. Finding the right pH balance in this step is crucial. If it’s too acidic, the wool may burn, and if it’s too basic, it may cause the wool to felt.
Mohamed Ghassen Nouira: So now we’re just monitoring the pH. It’s about 8, which is perfect.
Narrator: This is also the moment when the soluble dye is the most light-sensitive. Ghassen must cover the dye vat immediately to avoid too much exposure to light. Too much light can turn the dye from purple to blue, destroying a week’s worth of work.
When the material has soaked for the appropriate amount of time, Ghassen lifts the vat lid, exposing the mixture to light and air. This allows the mixture to oxidize.
Mohamed Ghassen Nouira: And this is how the color will gradually start to develop.
Narrator: But one round of vat dyeing won’t always do the trick, like with this silk scarf.
Mohamed Ghassen Nouira: It took me, like, eight months to produce, and it required, like, 800 pounds of fresh snails. And this is still not completed.
Narrator: And it’s not always guaranteed that the color will come out the same shade.
Mohamed Ghassen Nouira: Historically speaking, there isn’t a single hue or shade of Tyrian purple. It’s a range of shades that ranges from the color of clotted blood to the color of red-purple.
Narrator: This range is the result of mixing three different subspecies of murex snails: Hexaplex trunculus, which produces a violet blue color; Bolinus brandaris, which secretes the color of clotted blood; and the blood-mouth, or Stramonita haemastoma, which releases a rich red-purple color.
Tyrian purple dye dates back to the Bronze Age and is named after the Phoenician city of Tyre. Some historians believe it was produced as early as the 21st century BC. Ancient civilizations from Phoenicia to the Carthaginian and Roman empires prospered by producing and trading this dye. One of the production sites was Meninx, on the island of Djerba, which is now an archeological site.
Ali Drine: This dye is very precious and because it’s so precious Roman emperors ordered in the beginning of the Roman Empire that this color would be only used by the upper class in order to distinguish the social ranks.
Narrator: A text from the fourth century states that a single pound of Tyrian purple dye costs 3 pounds of gold. But production of this dye came to a screeching halt in the 15th century after the fall of the Byzantine Empire.
Ali Drine: The question is, why did it fade away? Because we don’t know how the dye was extracted and used, since the people who mastered the production passed away and the secret of the dye died with them.
Narrator: Ali says he’s grateful that Ghassen is reviving this culturally valuable dye, so Tunisians can reconnect with their ancestry. Ghassen learned about the dye at the age of 14 and was enthralled by its history in Carthage. Over a decade later, he found a murex snail on the shore oozing purple.
Mohamed Ghassen Nouira: My old passion for red-purple came rushing from its deep slumber, and I really had this revelation, and this is how my adventure for reviving this legendary dye started.
Narrator: Now, he hopes to ramp up his production, offering more shades of pigment.
Mohamed Ghassen Nouira: Well, of course, my dream is to enlarge this project and to, like, to create an old-fashioned dye factory and to produce more. But as I said, the main concern should always be to preserve the species, because if there is no murex, there is no dye.