"It's like wine-tasting. We draw it into our mouths and spit it out into a coffee spittoon," explained Kestenbaum, 58, president and CEO of Philadelphia-based Ellis Coffee Company. "We consider ourselves beverage specialists."
As part of the cupping process, Kestenbaum and his staff refuse to purchase coffee beans that they believe are either dirty, bitter, old or have mistakenly gone through fermentation.
"It's like if you eat pistachio nuts and you get one that is off, you can tell right away," said Kestenbaum. He noted that Ellis coffee is a blend of beans from different countries, and that all those characteristics mixed together create the Ellis taste.
The coffee that he samples ends up going to between 3,000 and 5,000 places in the northeastern United States, mostly to institutions like hotels, hospitals, universities, small companies and convenience stores.
Ellis has been a Philadelphia fixture since 1854, when it started as a coffee-roasting business and a grocery store. Kestenbaum considers it a high priority to keep the outfit, now located in the Bridesburg section of the city, in Philly proper.
"I believe in the city," he stated. "I want to see it flourish. It wasn't always a business-friendly environment, but I think it's doing better."
He went on to say that in the past, the state of Pennsylvania taxed businesses hard, but now things are starting to improve, in Philadelphia especially.
The mayor "understands that they have to help the businesses flourish to create tax dollars," said Kestenbaum.
In addition to his love of coffee, Kestenbaum has always had a strong sense of Jewish identity. As a child attending Temple Beth-El in the Long Island town of Great Neck, N.Y., he loved listening to Rabbi Jacob Phillip Rudin.
"He sounded like Moses on the mountain," recalled Kestenbaum, who now lives with his wife in Huntingdon Valley; his two sons are grown. "His final prayer at my Bar Mitzvah left an impression on me." The rabbi, quoting the priestly benediction recorded in the Torah, told the young Kestenbaum, "May the Lord bless you and keep you."
Continuing his Jewish involvement all these years later, Kestenbaum attends services with Rabbi Robert Leib at Old York Road Temple-Beth Am in Abington, who often reminds him of his old spiritual leader.
Kestenbaum didn't start at the top of the heap. Back in 1976, he worked for his father-in-law, which for some might seem like a burden. But not for him.
"He was a great teacher. We had a good relationship."
In the late 1980s, he took over as president and CEO, and he sees keeping his family involved as another top priority.
"In Judaism, it's important - and it's important in my life," said Kestenbaum, who currently works with several members of his family, including his son. "My father-in-law always impressed that on me, and I'm following in his footsteps."
Kestenbaum, whose son battles Crohn's disease, is also active with the Crohn's and Colitis Foundation of America, rising recently to the title of chair of the board of trustees.
"I just believe in giving back to the community," said the coffee maven. "It may have come from my father-in-law. He was always very philanthropic and very giving."