May One Sell Sourdough Starter Over Pesach?

Rav Ariel Ovadia

Question: To make sourdough, you need a “starter”. Some people have a specific starter they use for years. They want to sell it with their chometz but they want that specific starter back after Pesach. Is the sale valid considering that the seller really wants his starter back after yomtov?

Answer:  A sourdough starter is not a new thing. It is, in fact, the “se’or” that is mentioned in the pasuk as real chometz.

In the late 18th century, Rav Meshulam Igra wrote that he was makpid not to sell sourdough starters because it might not be a fully committed mechirah because the seller is relying on the non-Jew to give it back to him. 

Another issue the Poskim raise is the problem of rotzeh b’kiyumo. The Shulchan Aruch writes that one shouldn’t rent his pots to a non-Jew over Pesach if the gentile will use it for chometz because the owner is glad the pots are being used because this keeps it strong. This means that it is forbidden to want chometz to be around over Pesach. In this case, the seller wants the starter to stay around, which might be an issue. 

Both issues are dealt with by contemporary Poskim, who say they are not a real problem. Rav Forcheimer writes about a case where someone is making a simcha after Pesach and bakes challah and cakes beforehand and sells it to a non-Jew over Pesach. Even though he wants the chometz to be around, Rav Forcheimer says that this is not a problem because the issue of rotzeh b’kiyumo is only when one is deriving benefit from the existence of the chometz on Pesach. Getting enjoyment after Pesach from chometz that was sold over Pesach would not have this issue. 

As far as it not being a resolute mechiras chometz, I discussed this with Rav Shlomo Miller, and he told me that it is not a problem. He explained that every mechiras chometz is a resolute mechirah even though we know the seller wants it back right after Pesach, as he wouldn’t be selling it altogether if he didn’t want it back.

Bottom line, one may sell sourdough starter over Pesach.