When Bel Kaufman sits you down on her sofa and asks, “Are you comfortable?” the right answer, she reminds you, requires a Yiddish inflection, a shrug and the words, “I make a living.”

At 100 years old, Ms. Kaufman is still shpritzing jokes, Jewish and otherwise, which is in her genes. Her grandfather was the great Yiddish storyteller Sholem Aleichem, a writer who was able to squeeze heartbreaking humor out of the most threadbare deprivation and wove the bittersweet Tevye stories that became the source for “Fiddler on the Roof.”

This year, Ms. Kaufman did something more than tell jokes. She became one of the few adjunct professors in her age cohort and taught a course on Jewish humor at Hunter College, her alma mater. One of the jokes the class dissected:

“The Frenchman says: ‘I’m tired and thirsty. I must have wine.’ The German says: ‘I’m tired and thirsty. I must have beer.’ The Jew says: ‘I’m tired and thirsty. I must have diabetes.’ ”

“We were not just telling jokes,” Ms. Kaufman said in her book-lined Park Avenue study, her eyes glinting mischievously. “We were investigating why so many comedians are Jewish and so many Jewish jokes are so self-accusing.”