OUr Woman in the Lab

In the almost exclusively male domains of chemistry and kashrus, Dr. Judith Leff a”h laid the foundation to certify high-tech kosher ingredients

Kosher grocery shopping 2024. We pull a package of candy off the shelf, glance at it to check it has a kashrus symbol, and casually toss it into our cart.

What we don’t think much about is that somebody had to make sure the unpronounceable additives, preservatives, and colorants in the ingredients list are kosher. And as over the years, food became more high tech, kashrus supervision needed to turn high tech as well. Most of us are unaware that the person who pioneered the kosher certification of all those mysterious chemicals was an unassuming and brilliant woman with a short sheitel, glasses, and a warm smile, named Dr. Judith Leff (née Weisz) a”h.

A mother of three and grandmother of many, Dr. Judith Leff was nifteres this past November. And while she wasn’t a household name — that’s how she preferred things to be — she’s one of the unsung heroes of the male-dominated kashrus certification industry.

Wandering Jew

Judith Leff’s life literally took her around the world.