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Kashrus Awareness Staff

The Rise of a New Dough

Updated: Jun 2, 2022

Episode 3 - The Rising Issue with Sourdough Bread


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According to a US News & World Report survey, 85% of people reported a change to eating and food preparation due to COVID – and some healthy habits seem to be staying. The rising popularity of sourdough, whether baked at home or commercially, is one of the prominent new diet changes.

How does a kashrus issue finish off your starter after Pesach?


Rabbi Hisiger:

Chometz she'avar alav HaPesach is very relevant with regards to sourdough breads. They’ve become very, very popular nowadays.

Today, wherever you go, it's sourdough this and sourdough that. People are making sourdough in their houses and selling it, which is another topic for another day. There's the starter of the sourdough, which is mamish se'or; it's real chometz.


Rabbi Fishbane:

When we were growing up, sourdough bread was something that they made in the bakery once a week, and they barely sold half of it. You’re right - it is mamish se'or.

I think it definitely gained popularity during COVID. In general, the way we eat and prepare food has changed drastically during COVID, because people were home a lot and they started tinkering with various ideas. Our “inner chef” emerged and this fad took off.


Rabbi Hisiger:

Is sourdough an issue after Pesach? Is it something that people could sell

and still use after Yom Tov?


Rabbi Fishbane:

It's an interesting shailah, and this might make for a geshmake Shabbos Hagadol drasha.

Starter, as you know, takes weeks to ferment in order for it to get to that desired state of se'or. Since it's so time-consuming to create, so valuable, and the conditions have to be so right in order to produce it, when you sell it, there’s something called rotzeh b'kiyumo. You don't want the purchaser to come and say, "Okay, thank you very much. Here's $500 for that sourdough and I'll see you next year."

It's not so simple. Here is one of those times when you, as a consumer, need to know the shailah in order to ask the rav before. Rotzeh b'kiyumo - does the person really want to sell the item?


Rabbi Hisiger:

You're saying that the answer is too complicated for this forum, but it's definitely something that people have to keep in mind when they sell their chometz.


Rabbi Fishbane:

Yes, it is a shailah that has become more relevant to our generation, and consumers should consult with their rabbanim as to their opinions on selling sourdough starter over Pesach. (This shailah is only concerning the sale of personal sourdough starters. Rotzeh b’kiyumo would essentially leave you in possession of chometz on Pesach, and therefore even after Pesach it would still be assur b’hana’ah. Regarding buying from a store after Pesach, however, there is no concern, because even if the sale is rotzeh b’kiyumo, that is only a personal issur hana’ah for the person who sold it.

I’m not here to pasken l’halacha. I’m just raising the issues that an educated consumer would want to know more about. After all, she’ailas chacham is chatzi teshuvah.


The Takeaway:

From Start to Finish

Sourdough starters are a work of heart. Even if sold over Pesach, it’s questionable if the seller was truly willing to part with it, and if they are anxious for it to be returned. Ask your rav before you get started. Is the mechirah of sourdough considered legitimate?

This shailah is only concerning the sale of personal sourdough starters. Rotzeh b’kiyumo would essentially leave you in possession of chometz on Pesach, and therefore even after Pesach it would still be assur b’hana’ah. Regarding buying from a store after Pesach, however, there is no concern, because even if the sale is rotzeh b’kiyumo, that is only a personal issur hana’ah for the person who sold it.


Terms Defined:

"Rotzeh B’kiyumo

The term rotzeh b’kiyumooriginates in Maseches Avodah Zarah. If you desire an object's existence, then it is as if you are deriving hana'ah (benefit) from it. Regarding most chometz that people sell, if the gentile would eat it and pay them fair market value, they would be more than happy. In this case, people would not want the gentile to eat it and pay them for it, because of all the hard work involved in the starter. Thus, it would present a problem of rotzeh b’kiyumo - wanting its existence.




The Kashrus Awareness Campaign receives guidance from AKO, an umbrella association of kashrus organizations. We do not intend to render halachic decisions, nor do we affiliate with, nor endorse the contents of linked material. The project's mission is to inform and educate the kosher consumer to know what to look out for and what to inquire about., after all, sh’alas chochom is chatzi teshuvah. For all questions you have regarding halachah, please ask you local Rav for guidance.



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