Not quite azure, more of a midnight blue. That is apparently the actual color of
the biblical techelet, according to Prof. Zvi Koren, who spoke this week at the
Shenkar College’s International Edelstein Color Symposium.
the color that was used to dye the coat of the high priests in the time of the
temples, as well as the strings attached to the corners of men’s garments “so
that they may be seen and remind you of God’s commands,” as the Torah states. In
modern Hebrew usage, techelet is the color of a clear sky in the
The Masada of the North
Masada - A mountain of history
But the analysis of a small piece of dyed fabric that
archeologist Yigal Yadin found at Masada in the 1960s, dated to the first
century BCE, was what Koren recently used to determine not only the true hue of
techelet, but also the chemical breakdown that allowed him to establish
irrevocably that the source of this ancient dye was indeed the murex trunculus
However, Koren stressed that there were different types of murex
The type used for techelet, he told The Jerusalem Post on
Thursday, must be one that “not only has indigo, but is rich in it.”
professor at the department of chemical engineering at the Shenkar College of
Engineering and Design in Ramat Gan and director of its Edelstein Center for the
Analysis of Ancient Artifacts, Koren revealed over 15 years ago the origins of
the biblical purplish color argaman. The techelet discovery thus completes the
historic and archeological picture of the origins of the three ancient colors
most important in Judaism – the crimson shani, extracted from bugs, being the
Even as far back as the late 19th century, scholars “have supposed
and theorized that the source is murex trunculus,” Koren said. “But this never
had been proven to be true.
Only now we have authenticated that the
source is murex trunculus.”
The Talmud states the techelet is from a
hilazon – a sea snail – and does not elaborate.
“We know most of the
Jewish authorities call it bluish, lets say even with some green” – as in the
case of 11th-century commentator Rashi – “but most say some kind of shade of
blue,” Koren noted.
For over 20 years now, the Ptil Tekhelet association
for the promotion and distribution of techelet-dyed fringes has been producing
its color from the same snail. But the chemical process necessary for mass
production results in a slightly lighter hue, with fewer purple
According to Assaf Stein, who is in charge of dyeing and
mechanical development for the association, the difference in shade is more a
matter of taste than anything else, and certainly not a halachic setback for the
validity of the group’s dye.
“We try to reach a dark shade of blue, but
not too dark,” he said. “It is hard to determine what the Torah meant, and seems
that a singular shade of techelet wasn’t specified.
One can strive for
any kind of blue that is beautiful and durable,” produced from the correct
“Most people prefer the lighter blue fringes,” he added. “I
myself like the darker ones.”
And since both the dye and the fabric are
from natural products, and the dyeing process influenced by the temperature,
quality of materials and concentration of snails, no two batches will be
identical, Stein noted.
“You can actually go into a store and choose a
shade of techelet you like from a variety,” he said.
Koren, who made
aliya from New York 20 years ago and wears a colorful knitted kippa, stressed
that he didn’t pursue this enigma from the halachic perspective. “I’m a chemist,
a scientist interested in archeology, trying to find the original product,” he
said. “But of course, if it has halachic applications, all the
Koren, who reconstructed the ancient process of producing the
dye, said his find needn’t cast tekhelet production methods in a problematic
light. “I’m not a rabbi,” he said.
“But I believe that because it is so
difficult and time-consuming to do a dyeing using [the technique of] natural
reduction, it can be compared to the etrog citron fruit, where there are
different degrees of glorifying the command, but they are all
Koren’s take on techelet does not change the original Hebrew
concept of it being a color of the sky – just what time you look
“This is the color of the sky, but not in daytime, rather midnight,”
he said at the conference. “A midnight blue, a blue-purple. Because that’s when
you reach out and feel powerless. All your senses are defenseless. That is when
you see and hear the music of the night.”