From East to West: Where Do Sephardic and Ashkenazic Poskim Differ When It Comes to Kashering?

Rabbi Eli Gersten

In the last millennium, Jewish life flourished in two distinct and separate parts of the world: Sephardic Jewry in the Iberian Peninsula, North Africa and the Mideast, and Ashkenazic Jewry in Germany, Eastern Europe and France. Not surprisingly, both communities developed distinctive customs relating to dress, language, cuisine, professions, etc… In the area of Torah study and halacha as well, there emerged two separate styles and approaches of learning, though scholars in both communities communicated with each other and were aware of each other’s written works.

The Sephardic and halachic positions were most significantly recorded in two monumental works written in the sixteenth century. The Shulchan Aruch, composed by Rav Yosef Karo zt”l, who resided in Tzfat, Israel, is the main source of halachic practice for Sephardim.

The gloss on the Shulchan Aruch, known as the Rema, was composed by Rav Moshe Isserles zt”l, from Krakow, Poland (Rema is an acronym for the author’s name), and is the main source of Ashkenazic tradition. Though there are some significant points of conflict, amazingly, they are relatively few, which underscores the unity of Klal Yisrael and halacha. Even until the present time, Ashkenazim and Sephardim continue to adhere to their respective mesorot (traditions) of halacha.

In this article, we’ll highlight some of the major halachic differences between Sephardic and Ashkenazic traditions as related to chametz utensils and kashering for Pesach. As with all areas of halacha, it is advised to consult one’s rabbi for guidance.

Aino Ben Yomo

The Shulchan Aruch writes that if a chametz utensil was accidentally used on Pesach, the food may be eaten if the utensil was not previously used for chametz for 24 hours (referred to in halacha as “aino ben yomo”). This is because the ta’am (taste) of chametz that is absorbed in the utensil becomes stale after 24 hours have elapsed and the ta’am loses its halachic significance. The pan may not be used l’chatchila (intentionally) on Pesach unless kashered, because of a rabbinic decree, but if used b’dieved, (accidentally) the food remains kosher.

On the other hand, the Rema rules that even if the chametz utensil was not used for 24 hours (aino ben yomo), the food is forbidden and may not be eaten on Pesach. The Rema agrees that during year-round use, if a utensil was used for non-kosher food and kosher food was then prepared with that utensil, the food is kosher (b’dieved), but the rules that govern Pesach are more stringent.

Example: On Pesach, I accidentally stirred my kosher for Pesach pot of soup with a clean chametz spoon. The spoon had not been used with chametz for more than 24 hours. Can I eat the soup?

• A Sephardi may eat the soup and may continue using the pot.

• An Ashkenazi must throw away the soup and put away the pot until after Pesach.

Rov Tashmisho – Primary Use

A chametz utensil that is commonly used with heat cannot be used on Pesach unless kashered beforehand. If it is only used with cold chametz, it can be scrubbed clean and then used for Pesach.

What if the primary use is cold, but occasionally it is used with heat? The Shulchan Aruch (451:6) rules that the halachic status is determined by the primary use (known as rov tashmisho). Thus, a chametz utensil that is ordinarily used for cold food, but on rare occasions is used for hot, can be used on Pesach (without kashering) if it is properly cleaned. There is one caveat; the utensil must not have been used with chametz in the past 24 hours. Why should rov tashmisho obviate the need for kashering despite the occasional hot chametz use? The answer is that, as previously explained, once 24 hours have elapsed, food cooked in a chametz pot is always kosher according to Sephardic tradition. The requirement to kasher a vessel after 24 hours is only rabbinic. As such, the rabbis instituted a leniency, that the halachic status of a utensil is based on primary use.

The Rema disagrees. According to the Rema, one must kasher a utensil used for chametz even if only one time. Moreover, the Rema is strict even if one is unsure if the utensil was used for chametz.

Example: A kiddush cup is usually used cold, but occasionally it is washed with hot water together with chametz dishes. How should one prepare a silver kiddush cup for Pesach?

• A Sephardi may prepare the cup for Pesach by scrubbing it clean, so long as the cup had not been used with chametz in the past 24 hours.

• An Ashkenazi must kasher the cup by pouring boiling water on the cup. (The cup is kashered the same way it absorbed chametz. Since it absorbed with irui (pouring), it is kashered the same way.)

Kashering a Ceramic Sink

The Shulchan Aruch (451:1) writes that cheres (earthenware) utensils cannot be kashered for Pesach or year-round if used with heat. It is generally accepted that porcelain, China and modern-day ceramics are included in this category as well. Ashkenazim cannot kasher a ceramic sink since the temperature is occasionally very hot.

On the other hand, Rav Ovadia Yosef zt”l writes that Sephardim can use a ceramic sink for Pesach because Sephardim are lenient with rov tashmisho. If the primary use of a utensil is cold, it can be used after 24 hours without kashering. The rov tashmisho (primary use) of water in a sink is below yad soledet (too hot to hold), which is treated as cold in halacha. Still, Rav Ovadia Yosef zt”l writes that boiling water must be poured on all the surfaces of the sink three times. Presumably, this is because when dealing with Pesach, there is some absorption of chametz even on cold ceramic or earthenware surfaces.

Kashering Glass

The Shulchan Aruch (451:26) writes that glass utensils need not be kashered for Pesach, even if they were used with hot chametz. This is because glass does not absorb, and it is therefore sufficient to scrub them clean. Contemporary Sephardic poskim, including Rav Ovadia Yosef zt”l, write that the same applies to Pyrex, even though it is used directly on the fire.

The Rema disagrees and holds that glass does absorb. Moreover, since glass is made from sand, it is viewed like ceramic and cannot be kashered.

Example: How should a glass stovetop be kashered?

• A Sephardi may use a glass stovetop after scrubbing it clean. No kashering is necessary.

• An Ashkenazi must clean the stovetop surface well and not use it for 24 hours. During Pesach, pots should not be placed directly on the stove surface since glass cannot be kashered. Rather, an aluminum or copper disk (or other metals) should be placed directly under the pots.

Example: I have a chametz set of glass plates and bowls. Can they be used for Pesach?

• A Sephardi may use these utensils after scrubbing them clean. No kashering is necessary.

• An Ashkenazi may not use these utensils. There is no way to kasher them for Pesach.

Kashering Chametz Utensils When They Are Still Ben Yomo

Shulchan Aruch (452:1) writes that one may kasher chametz utensils (provided this is done before the fifth hour on erev Pesach when chametz can still be eaten), even if the utensils were used with chametz within the past 24 hours (ben yomo).

Although the Rema agrees in principle with the Shulchan Aruch that this is acceptable, still he writes that the custom of Ashkenazim is not to kasher any utensil without first waiting 24 hours. Sephardim, however, do not have this custom. Though there are other reasons why it is proper to wait before kashering until the utensils have not been used for 24 hours, strictly speaking there is no need for a Sephardi to do so.

Example: I cooked chametz in a pot on erev Pesach in the morning. Can I still kasher the pot for Pesach?

• A Sephardi may kasher the pot with hagalah before the fifth hour on erev Pesach.

• The custom of Ashkenazim is not to kasher the pot, and it should be put away for the duration of Pesach.


Rabbi Eli Gersten
Rabbi Eli Gersten serves as OU rabbinic coordinator and recorder of OU policy.

Get the OU Kosher App

Search all OU Products for Passover and year-round. Get Kosher alerts, new product updates and just click to ask a question.