No longer on the fringe
Everything you ever wanted to know about 'techelet,' the dye created from the Murex trunculus to color ritual garments.
Murex trunculus Photo: Courtesy
Acord of sky blue thread – called “techelet” in the Bible – must be tied among
the ritual fringes worn by observant Jews (Numbers 15:37- 40). Despite the
frequency with which this command is repeated – it’s part of the paragraphs
following the twice daily obligatory recitation of the Shema – the secret of
creating the required specific blue was lost for more than a
Rather than use the wrong color, plain white fringes were
substituted for blue ones.
Techelet had additional uses in ancient
Israel, but it always connoted status, prestige and wealth. According to the
Talmud, the sole legitimate source of the techelet dye is the marine hilazon,
identified by most as Murex trunculus or banded rock murex, a kind of snail. But
despite intense research and experimentation, until recently the ancient
technology couldn’t be achieved by contemporary scientists.
Blue tells you everything you ever wanted to know and more about this elusive
color and the odyssey of its rediscovery. Enlivening this scholarly,
encyclopedic description of the color are the vicissitudes of the drama of the
Author Baruch Sterman is a physicist who helped develop the
modern blue dying techniques, and a cofounder of the Ptil Techelet Association.
He and his wife Judy Taubes Sterman, whose kitchen was an early laboratory for
the experiments, are a talented and knowledgeable writing team.
example, they raise the question of the discovery of the Murex trunculus shells
amid the excavation on Mount Zion, the westernmost section of Jerusalem in the
Second Temple period.
Jerusalem is, of course, landlocked.
were a few dozen shells doing amid first-century artifacts from the time when
the Temple of Herod stood? Archeologist Shimon Gibson, one of the many experts
consulted in this story, suggested that the shells were brought to Jerusalem for
Blue dye was in demand in the Temple because priests needed
to color wool and the same retailers would be selling ritual fringes to the
“Perhaps, as a striped barbershop pole advertises
haircutting services, a snail shell outside a door declared to the public,
‘techelet sold here,’” said Gibson.
The shells would have provided
authorization that genuine blue was for sale, and not fake blue strings, known
as kala idan. The Talmud issued ominous threats to unprincipled dealers who
might sell counterfeit blue dye.
The imitation, created from plantderived
indigo, looked identical to the snail-derived blue. Something like slipping a
zirconium instead of a diamond into a royal tiara. But unlike the stones,
techelet couldn’t be tested. Today there is a test.
Half a century after
Yigael Yadin excavated Masada, a scrap of cloth from the dig was examined by
chemist Zvi Koren of the Shenkar College of Engineering and Design, now in Ramat
Gan. In 2011, Koren confirmed that the dark blue embroidered stripe on the cloth
had been colored with dye from murex trunculus.
DYE MASTERS of ancient
times were held in great esteem. The Jerusalem Talmud reports that they walked
around with a wool tuft behind their ears to advertise membership in their elite
guild. Rightly so. Dyeing in ancient times was a complex
Color had to last through washing and sunshine. The dyer had
to find a chemical ploy that would allow dye to enter the fabric, adhere and
The dyes were harsh and stank, particularly with dye from
snails. Dyeing with murex secretions meant working very fast before the color
changed and using large qualities of snails; 7,000 for a single pound of
After the destruction of the Temple, there was no more priestly
service, and the manufacture of blue cloth needed by the priests ended. Jews in
Palestine and the rest of the Roman Empire continued to follow biblical
commandments to wear techelet strings on the fringes of their garments. But soon
the special blue fell under the category of “purple cloth,” restricted to royal
production, forbidden to be sold by commoners. Even if they could get techelet,
it was prohibitively expensive. Plant-derived indigo became the common source of
blue. Hence, the tradition of wearing the blue strings as well as the knowledge
of producing it disappeared almost completely in the seventh
Until modern times. Numerous learned aficionados have devoted
themselves to the revival. The most famous of them was Rabbi Isaac Halevi
Herzog, who earned his doctorate investigating what he called
His thesis was called The Dyeing of Purple in Ancient
Israel. In it, he debunked the conclusions of Rabbi Gershon Henokh Leiner of
Poland, the Radzyner rebbe, who had researched the subject in the 19th century.
But Rabbi Herzog himself erred in his refusal to accept the Murex trunculus as
the source of biblical blue because it seemed to produce only purple, and not
The conundrum was resolved by Otto Elsner, a dye chemist from
the Shenkar College. To cope with the rancid smell of the snails, Elsner set up
his lab bench near an open window. Serendipitously, on bright sunny days, when
the dye was bathed in Israeli sunshine, it turned sky-blue.
challenge was to make blue ritual fringes, creating first a cottage industry and
then a more commercial production line. For the first time in 1,300 years,
techelet fringes were once again available, allowing persons to fulfill the
On one hand The Rarest Blue indulges the reader in
lofty reveries about the nature and philosophy of blueness.
mere coincidence that the techelet string hangs specifically from the edge at
the corners of a garment.
The blue thread emphasizes the importance of
man’s acceptance of his mission in life and his commitment to moral and
On the other hand, the book provides intriguing
descriptions of the hands-on process of making the dye and fringes, from the
gathering of the marine snail to the intricacy of fringe-tying. There’s even a
suggestion for a home science experiment.
The Stermans are themselves
among the knights on this noble quest. The Rarest Blue has been written with the
same energy, erudition and delight in Judaism that characterizes the
You’ll want a copy in your personal library. ■