As thousands of Jewish families in the Midwest enjoyed fresh, chalav Yisrael milk over Passover, few knew that their dairy drink was due to the efforts of a humble CPA named Yitzchok Eliyahu (Irwin) Kosofsky, who passed away prior to the holiday at the age of 89.

Kosofsky was born in 1931 in Chicago to traditional Jewish immigrants from Lithuania and Ukraine, the oldest of three children. His lifelong connection to Chabad began when his parents, Louis and Bertha, sent him to the talmud Torah (after-school Judaic education program) at Congregation Bnei Ruven, then one of five Chabad synagogues in the city, and just a few blocks from their home on the then-predominantly Jewish West Side of Chicago.

In 1942, the sixth Chabad rebbe—Rabbi Yosef Yitzchak Schneersohn, of righteous memory—visited Chicago for the second time, having been there previously in 1929. For the rest of his life, Kosofsky would lovingly recall the moment the Rebbe spoke to him and his talmud Torah classmates.

Looking for a more rigorous experience, he joined a Talmud class taught by Rabbi Sholom Posner, then the shammash of the synagogue and the Rebbe’s emissary to the city.

In high school, he continued his afternoon Torah studies, first at a Chabad yeshivah directed by Rabbi Yosef Wineberg, and later at Hebrew Theological College-Beis HaMidrash LaTorah, known today as Skokie Yeshiva.

In 1951, he married Reitza Kushner. After earning a degree in accounting at Roosevelt College, he worked for many years as a CPA, and as comptroller for a company that refined precious metals.

They joined the small core of young families deeply committed to Judaism and the ideals of Chabad-Lubavitch.

After his retirement, Kosofsky devoted a significant part of his day to Torah study.
After his retirement, Kosofsky devoted a significant part of his day to Torah study.

Spreading Chabad Ideals in Chicago

Through the leading Chabad chassidim in Chicago, notably Rabbi Shlomo Zalman and Chaya Sarah Hecht, and Rabbi Herschel and Chava Schusterman, the Kosofskys developed a connection with the Rebbe—Rabbi Menachem M. Schneerson, of righteous memory.

In the summer of 1955, he met the Rebbe for the first time. During that meeting, the Rebbe encouraged him to study Tanya, the foundational work of Chabad Chassidism, something he did for decades with a series of study partners.

In the 1960s and ’70s, encouraged by the Rebbe, and under the direction of Rabbi Tzvi Hirsch Meisels (the Veitziner Rav), Kosofsky arranged the oversight and production of chalav Yisrael milk for Chicago. This involved sending a mashgiach to a farm and dairy in Wisconsin and trucking the milk into Chicago. At that time, only a handful of families were careful to drink the special milk, which was supervised to ensure that it contained no unkosher ingredients. There were many challenges over the years, but he received encouragement from the Rebbe and did not give up. The effort has since become fully independent and financially viable.

At Lubavitch World Headquarters at 770 Eastern Parkway with Rabbis Chaim B. Halberstam and Yonasan Hackner, who worked the phone lines on the New York end to bring the Rebbe's talks to communities all over the world, including the live hookup in the Kosofsky home.
At Lubavitch World Headquarters at 770 Eastern Parkway with Rabbis Chaim B. Halberstam and Yonasan Hackner, who worked the phone lines on the New York end to bring the Rebbe's talks to communities all over the world, including the live hookup in the Kosofsky home.

An Eager Volunteer for Many Projects

Despite the pressures of work and raising a large family, he found time to volunteer, assisting Rabbi Hecht in arranging shofar-blowers to visit area hospitals on Rosh Hashanah and other projects.

In the early 1970s, when the Rebbe’s farbrengens began to be broadcast over the phone lines, Kosofsky offered his home for the hook-up and experimented with different ways to attach wires from the old-fashioned phone box to a reel-to-reel tape recorder borrowed from Mr. Jacob (Yankel) Katz, a local philanthropist and Chassid.

When he and his wife heard the Rebbe encouraging his audience to reach out to the Jews then beginning to leave Russia, they decided to act. She founded the Chicago chapter of FREE, which assisted thousands of new immigrants to integrate into American and Jewish society. It now has several branches across Chicagoland.

The Rebbe took a keen interest in their work. In an interview with JEM’s “My Encounter Project,” he recalled receiving an urgent call from the Rebbe’s office on erev Yom Kippur (perhaps the busiest day on the Jewish calendar) with a message from the Rebbe: If a Jew was willing to undergo circumcision, they were to provide the procedure as soon as possible.

As the Chabad presence in Chicago flourished, Kosofsky provided expertise and advice to the burgeoning cluster of educational and social organizations, and served as a founding board member of Seymour J. Abrams Cheder Lubavitch Hebrew Day School and Lubavitch Girls High School.

With a fondness for cooking, he catered many communal celebrations, including the annual Rosh Chodesh Kislev farbrengens.

Outside Lubavitch World Headquarters at a family wedding.
Outside Lubavitch World Headquarters at a family wedding.

“He had an unassuming and straightforward way of getting things done,” attests Rabbi Boruch Hertz, spiritual leader of Bnei Ruven and rabbi of the Chabad community in Chicago. “He was at the center of the action but he never wanted the spotlight on himself. He was a warm and likable person who went out of his way to help others, a passionate Chassid who got things done with energy and warmth.”

An example was his participation in the congregation’s evening learning program. Not satisfied just to learn there after work, he made sure to bake a cake every day to share with the participants.

“He was a bridge who brought people together,” continues the rabbi. “He was an old-timer with a young heart, whom everyone looked up to and was drawn to.”

For decades, tzedakah collectors and visiting rabbis knew that they could find a warm meal and a freshly made bed at the Kosofsky residence, and young couples in the rapidly growing community turned to them for guidance and advice.

Together with his wife, he watched with pride as their children took up positions as shluchim in Australia, Argentina and across the United States.

In 2014, they moved in with their daughter in California, where he continued to attend minyan twice a day and study Talmud daily on his iPad.

In addition to his wife of 68 years, he leaves behind their children: Nechama Prus (Newton, Mass.); Mina Gordon (Melbourne, Australia); Rabbi Noach Kosofsky (Longmeadow, Mass.); Rabbi Chaim Kosofsky (Longmeadow, Mass.); Chany Mochkin (Rochester, N.Y.); Baila Chein (Buenos Aires); Rabbi Lipman Kosofsky (Brooklyn, N.Y.); Sori Levitansky (S. Monica, Calif.); Devori Baumgarten (Rockaway, N.J.); as well as hundreds of grandchildren and great-grandchildren.

He also leaves two sisters, Francine Brief (Morton Grove, Ill.) and Rochelle Baum (Chicago).

He was predeceased by a great-granddaughter, Miriam Baila Goldszweig.

Yitzchok and Raitza Kosofsky surrounded by some of their descendants.
Yitzchok and Raitza Kosofsky surrounded by some of their descendants.
Yitzchok Kosofsky
Yitzchok Kosofsky