Rabbi Moshe Zywica

An Eruv Tavshilin Q&A for Shavuos 5783

Q:  What is the reason for Eruv Tavshilin? A: When the second or eighth day of yom tov falls on Shabbat, or if Shabbat falls immediately after yom tov, it is rabbinically forbidden to cook or prepare on yom tov for Shabbat. When executed properly, an Eruv Tavshilin allows one to prepare food for Shabbat on yom tov. This year, the second day of Shavuot […]

Pruzbul: Ask the Rabbi

I have a friend who owes me 1,000 dollars.  He told me that once Rosh Hashanah comes, he will not have to pay me back.  Is that true? To answer we have to start from the beginning.  The Torah says in Devarim (Chapter 15, verses 1-2) “at the end of seven years…every creditor should release […]

Summer’s here! OU Kosher answers your questions on park BBQ grills, keeping kosher on a cruise and more…

 OU Kosher presents questions frequently asked  by consumers on the OU Kosher Hotline (212-613-8241) for the summer. Questions may also be submitted to kosherq@ou.org or chat with us by clicking on the chat bubble on the right bottom of the screen.       * * * 1.    Q: Is it possible to cook on a BBQ that was […]

In Remembrance of Our Loved Ones

It is customary on Yom Kippur when Yizkor (the memorial service) is recited, as well as on the Shalosh Regalim (Passover, Sukkot and Shavuot), to light a candle in memory of loved ones who have passed away.  This practice was referenced as far back as the Talmudic times when it was recorded in Tractate Ketubot […]

Getting the Flavor of Certifying Flavors: A Primer

The balance is a delicate one in an era when brand loyalty has diminished and tastes are ever more fickle.

The flavor industry has grown from rather humble origins in the mid-nineteenth century, when processed foods first came to prominence, into a $1.5 billion dollar industry that churns out 10,000 new flavors a year. For purposes of kosher certification, chemicals and natural ingredients the raw components of a flavor are divided into three categories: natural, non-kosher, and “in between.” The natural category includes tea, cocoa powder, honey, lemon oil and other inherently kosher materials, as well as chemicals derived entirely from natural sources, such as heliotropin, a transmutation of petroleum.


A history of the fat substitute Olestra and its Kosher status.