Stewart C. Feinberg

Stewart C. Feinberg, 78, of Exton, PA passed away peacefully on April 3, 2026, after a months-long illness.

Stewart, lovingly referred to as Stew or Stewie, was born in 1947, in Brooklyn, NY. He was the second son to Clara and Louis Feinberg, arriving one minute before his twin brother, Melvin. Stew grew up in Brooklyn and attended Yeshiva University Boys High School, where he was on the swim team, debate team, and a literary editor.

After graduating from high school, Stew attended Brooklyn College, where he studied chemistry. Stew moved on to obtain his Ph.D. in polymer chemistry at Brooklyn Polytechnic Institute, but, when his advisor unexpectedly died, Stew transferred to the University of Akron to finish his studies. On his first day in Akron, he was looking to rent a room in a kosher home and went to the Jewish Community Center where Beverly Kopelson happened to be working at a children's camp. The receptionist asked her to show him around. The rest is history. Stew and Bev were married in 1972. They welcomed their first son, Jonathan, in 1975, and their second son, Daniel, in 1979. After living in Columbia, MD and Pittsburgh, in 1980, the family settled in Exton, PA, where they found a wonderful community and lived for the next 46 years.

Following the completion of his Ph.D., Stew had a long and productive career as a research chemist, starting at W.R. Grace and then ARCO Chemical Co, before moving on to DuPont where he spent the majority of his professional life. He is listed as an inventor on 22 patents! His family members have even read some of those patents, but they have yet to understand them.

Stew had the mind and the mannerisms of a scientist. He was known to label every item he owned with the date and location of where he bought it. Stew’s family, especially his grandchildren, found great amusement in locating his labels on everything, from his phone charger, to his travel-size baby powder container, to his treasured jar of crushed red pepper. 

Stew was a medical miracle. Diagnosed with Type 1 Diabetes at the age of 19, he knew he was at risk for many health complications and a reduced life expectancy. Applying his usual intellectual rigor and love for data, he managed his condition meticulously for close to 60 years. His treating physicians told him he was the most obsessive of any person with diabetes they had ever encountered. That made him proud.

Outside of his work, Stew devoted boundless energy to serving his community. Much of his free time was spent at his synagogue, Kesher Israel Congregation in West Chester, PA. He began serving as a board member in the 1980s, eventually rising to the position of President. Following his presidency, he was a leader or member of too many Congregation committees to count. 

Beyond the synagogue, Stew’s commitment to volunteering and service spanned his entire adult life. He coached his sons’ baseball teams with the Exton Little League and was a member of that organization’s board of directors. He promoted the education and development of the next generation of scientists as a judge for the Delaware Valley Science Fairs. He provided food to homebound seniors through Meals on Wheels. He drove people with disabilities to medical appointments for Community Volunteers in Medicine. He donated blood as often as he was allowed. And he was always politically engaged, working as a poll watcher for the Chester County Democratic Committee.

In his retirement, when he was not serving his community, Stew found joy in traveling with his wife, Bev; cheering (and occasionally booing) his beloved Philadelphia Eagles; enrolling in online courses; studying genealogy and collecting data on his family’s history dating to the late 19th century; running in local 5k races and striving to win his 60+ and 70+ age groups; getting coffee from Wawa; and bird watching via the birdfeeder camera installed on his backyard patio.

Stew could never have too much time with his family. He was a loving husband, devoted father and father-in-law, and, most of all, a doting grandfather. Stew could often be found wearing a T-shirt boldly advertising his favorite name, “Grandpa.” He never missed a soccer game, school play, or birthday. He insisted on having a family photo at every gathering or meal. He told everyone who would listen about the accomplishments of his children and grandchildren.

Stew is survived by his wife, Beverly Feinberg; sons Daniel Feinberg and Jonathan Feinberg; daughter-in-law, Julie Feinberg; grandchildren, Zoe, Marley, and Leo Feinberg; twin brother, Melvin Feinberg; as well as many nieces, nephews, cousins, and friends. He was predeceased by his older brother, Norman Feinberg. Stew will be missed dearly and remembered fondly. 

Friends and family who wish to honor Stew are encouraged to make a donation to a charity of their choice that does the work of tikkun olam, a core Jewish concept that means “repairing the world.” Some of Stew’s favorite organizations include Breakthrough T1D (formerly Juvenile Diabetes Research Foundation), Delaware Valley Science Fairs, and the National Police Accountability Project

Arrangements by DellaVecchia, Reilly, Smith & Boyd Funeral Home, Inc. of West Chester, PA 610-696-1181; www.DellaFH.com