There are substantive discussions by Rabbi Asher Weiss, for example:

הרב אשר וייס – תכלת החדש

That is simple. Like Rabbi Shlomo Zalman and Rabbi Shlomo Fischer, he too is one of the substantive ones (those who are not influenced by politics and are willing to engage in a serious and scientific inquiry).

Rabbi Shlomo Fischer opposed wearing techelet, and he would refer people to his son, who investigated the matter.

Maybe the report I heard was mistaken, or maybe I do not remember well.

With God’s help, 27 Kislev 5782 (the eve of the 133rd birthday of Rabbi Isaac Herzog)

On the occasion of the eve of Rabbi Herzog’s birthday, since he dealt extensively with attempts to identify techelet, I came across the article by Dr. Baruch Sterman, “Rabbi Herzog and the Search for Techelet.” Rabbi Herzog leaned toward the banded dye-murex, but this did not fit with the fact that the color of the murex is purple and not blue.

According to the author, this problem was solved by Professor Elsner’s discovery that if the dye solution from the murex is exposed during a certain stage of processing, it turns a “sky-blue” color.

But what I do not understand is the author’s statement that “on the chemical level, the snail produces a mixture of pure techelet (sky-blue), which is the indigo molecule.”

And here I ask: if the substance produced from the snail is “indigo,” what is the difference between it and the “indigo” produced from kala ilan? After all, the Talmud describes a chemical test that distinguishes between techelet and kala ilan, yet they are both “indigo”?

Best regards, Elieam Fishel Workheimer

What is the test that the Talmud suggests? I thought the color of kala ilan was supposed to be identical, and that this is one of the proofs.

Rabbi Shlomo Zalman Auerbach actually did express himself on the matter, and both members of the Ptil Tekhelet association and Rabbi Menachem Burstein, who dealt with the issue, approached him and showed him the snails and the findings. In principle he agreed with what they were saying, but he told those who approached him that “you need to be younger to issue a ruling on this,” and that he did not want “to be a second Radzyner,” and that in his youth “they would throw out of the mikveh anyone who went around with the techelet of Radzyn.”

Therefore he did not issue a public ruling on the matter, even though it seemed that he agreed that this was indeed the genuine techelet.

His son-in-law Rabbi Zalman Nechemia wore techelet, and his son Rabbi Shmuel was the teacher of Rabbi Eliyahu Tavger of the Ptil Tekhelet association.

Rabbi Tavger related that he asked his teacher Rabbi Shmuel Auerbach for a letter of recommendation so that he could go with it to the leading halakhic authorities and show that he had backing. Rabbi Shmuel told him that there was no point in going to the leading halakhic authorities to convince them on this issue, because they would not want to hear about it, since they do not deal with innovations at all, only with things that have an established tradition.

He suggested that he turn to mid-level halakhic authorities and promote the matter from there.

With God’s help, the third day of Hanukkah 5782

Yishai — greetings,

The test for techelet is described in Babylonian Talmud Menachot 42b–43a:

“…And does techelet have no test? But Rav Yitzhak son of Rav Yehuda tested it: one brings alum, fenugreek juice, and urine that is forty days old, and soaks it in them from evening until morning. If its appearance changed, it is invalid; if its appearance did not change, it is valid. And Rav Adda, before Rava, said in the name of Rav Avira: one brings leaven made from barley flour and bakes it into it. If it improved, it is valid; if it worsened, it is invalid…”

With bright Hanukkah blessings, Elieam Fishel Workheimer

Rabbi Shlomo Moshe Sheinman tried to reconstruct the methods of testing techelet, both according to Rashi and according to Maimonides. His experiments are described in his article “Solving Fundamental Problems in Techelet,” chapter 15: “The Techelet Tests That I Performed.” His remarks are cited in the article by Dr. Moshe Raanan, “The granary weevil ‘shevlilta’ (Menachot 42b),” on the Daf Yomi Portal.

With bright Hanukkah blessings, Elieam Fishel Workheimer

In the article “The Messiah’s Snail” (on the Calcalist website), the remarks of a marine biologist, Dr. Shaul Kaplan, are mentioned. He says that all the signs mentioned by the Sages fit the janthina (which was also Rabbi Herzog’s view). The problem with janthina is that no way has been found to produce blue dye from it, and because of this Dr. Kaplan gave up and began raising a “conspiracy theory” according to which the Jews who produced techelet deliberately misled people in describing their snail, so that their monopoly would not be harmed.

In my humble opinion, since janthina is the only snail that fits the Sages’ description very well, we should wait patiently until the chemist is found who succeeds in producing techelet from it. Ancient technologies that were lost can be reconstructed as science advances, and in my opinion it is worth continuing to wait.

Best regards, Elieam Fishel Workheimer

In the article “Real Blue Is Red” (on the Davidson Institute website), the difficulty of producing a stable, non-toxic blue dye is described, and it reports that researchers in Brazil succeeded in producing a stable blue dye from beets.

It is worth noting that from Maimonides’ wording it seems that the definition of techelet is a colorfast dye. It may therefore be that according to Maimonides the need for the snail was because that was the only dye that was colorfast, and perhaps if a stable non-toxic blue dye from beets were found, then according to Maimonides even techelet from beets might work. Indeed, there would even be a good omen in it: “that our enemies, those who hate us, and all who seek our harm should depart.” 🙂

A reinforcement for the doubts about identifying techelet with the porphyra produced from the banded dye-murex (though not a total rejection of this identification) appears in the article by Rabbi Yehoshua Enbal, “The Thorns of the Murex” (from HaOtzar 11), with a link to the Wikipedia article under “Banded Dye-Murex.”

Best regards, Elieam Fishel Workheimer

Today someone who studied with Rabbi Michael Abraham told me that he remembers that Rabbi Michael Abraham wears techelet. Is that true? And did the Rabbi study the topic and the findings and rule that way, or is it more of a general impression?

For whoever asked about the difference from “kala ilan”: both are indigo, and as far as I know the shade is completely identical. The difference is in the chemical bond that is formed, which is much stronger in the indigo produced from the murex. The chemical explanation is in the book “A Taste of the Heavens”; I assume it can also be found online.

Absolutely true. See my first reply. I checked it, and it seems convincing. In any case, there is at least a Torah-level doubt here.