Rabbi Leizer Teitelbaum was born in Germany to Rabbi Michoel and Rebbetzin Esther Teitelbaum in 5708 (1948). He and his parents immigrated to the United States by boat when he was 3 ½ years old. It was a long journey and Rabbi Teitelbaum shared a cabin with his mother, while his father stayed in a communal men’s barracks! After coming to America, Rabbi Teitelbaum lived with his family in the Bronx, East Flatbush, and Brownsville before moving to Crown Heights. In 5731 (1971), Rabbi Teitelbaum married his wife, Brocha, and they lived in Crown Heights while he learned in kollel.

After kollel, Rabbi Teitelbaum and his wife moved first to Miami and then to Seattle where he was part of the Hanhola of the yeshivas there. Rabbi Teitelbaum looked after the bochurim, ensuring that they came to seder on time, and was available to answer all of their questions. While living in Seattle, Rabbi Teitelbaum also served as a shochet (ritual slaughterer) for the Jewish community for many years and worked for Vancouver Kosher (now known as BC Kosher). In addition, Rabbi Teitelbaum worked as a mashgiach for the OK while he lived in Seattle, visiting various facilities, including a grape juice plant, an ice-cream factory, and a dried fruit plant.

After a fourteen year hiatus from Brooklyn, in 1987 Rabbi Teitelbaum and his wife moved back to Crown Heights and he began working for OK Kosher Certification full-time. When Rabbi Teitelbaum started working for the OK, the world headquarters was still located in Rabbi Bernard Levy’s house in Boro Park. After spending a few months learning the ropes, Rabbi Teitelbaum began traveling extensively on behalf of the OK. At the time, Rabbi Teitelbaum’s travel itinerary for Annual Visits (yearly executive inspections) was arranged so that he would return to the same area many times during the same trip. During each return trip to an area, Rabbi Teitelbaum would make surprise visits to facilities in the area and check up on their compliance with OK policies.

One of Rabbi Teitelbaum’s early memories of working full-time at the OK was his first trip on behalf of the OK – supervising a new fish production in Korea. “In Korea, they work an 11 hour day, including Shabbos. I was late (due to flight problems) on my first day at the factory, and I discovered the workers already packing fish with a kosher symbol. I had to tell the workers to remove the kosher symbol from those packages. I also realized that if the workers packed the kosher fish before I got there, they must have also packed the kosher fish without a mashgiach every Shabbos!” Since that first trip, Rabbi Teitelbaum has traveled all over the United States and Canada, as well as to India, Japan, Australia, China, Chile, Russia, Ukraine, and many countries in Europe. Our computer system has over 3,000 inspection and set-up visits logged in for Rabbi Teitelbaum!

Rabbi Teitelbaum is the kind of rabbi who does not leave anything for the last minute. He is punctual and makes sure to take care of important matters immediately. One of the rabbis once passed by the fax machine on a Tuesday afternoon and noticed a fax (with his visit report) coming in from Rabbi Teitelbaum that was dated the next day, Wednesday morning – Rabbi Teitelbaum had sent the fax from Australia where it was already a day later – and the fax was in New York a day earlier than it was sent! The office staff had to wait a day to enter the visit into our computer system because Wednesday had not yet arrived in the U.S.!

In addition to his vast expertise in the field of kashrus, Rabbi Teitelbaum is also trained in shechita (as mentioned earlier) and safrus (scribe), enabling him to write and check mezuzos, tefillin and Sefer Torahs.

According to Rabbi Don Yoel Levy, Kashrus Administrator of OK Kosher Certification, “Rabbi Teitelbaum is one of the biggest experts in kashrus today. He has the unique combination of deep understanding of both the halachic and technical aspects of kashrus.”

What Other People Say About Rabbi Teitelbaum


“Rabbi Teitelbaum has an incredible breadth and depth of knowledge on almost every subject, from obscure chemical processes to a clear, precise understanding of complicated Halachic topics. This, coupled with his ability to think outside of the box, makes it a pleasure to work with him.”
– Rabbi Chaim Cohn
Rabbinic Coordinator, OK Kosher Certification


“I dormed with him and learned with him in yeshiva for many years. Rabbi Teitelbaum learned Shas and poskim with great hasmoda and finished the entire Talmud while still in yeshiva. Rabbi Teitelbaum held prominent positions in many yeshivos, but he was not able to utilize his great knowledge and understanding of halacha. When he came to the OK, I saw right away that Rabbi Teitelbaum found his place and he was very successful, deciding complex questions of halacha and handling all of the technical aspects of kashrus as well. Rabbi Teitelbaum has a very unique and outstanding combination of deep knowledge and devotion to the subject of kashrus, coupled with an understanding of technology and its place in kashrus.”
– Rabbi S.B. Levin
Head Librarian of Chabad Library
Rabbi Teitelbaum has an incredible breadth and depth of knowledge on almost every subject, from obscure chemical processes to a clear, precise understanding of complicated Halachic topics. This, coupled with his ability to think outside of the box, makes it a pleasure to work with him.