There is a Rabbinic prohibition on benefiting from chametz that was owned by a Jew over Passover. In recent years, an issue was raised in the New York area that a major distributor of grocery items in the northeastern United States was suspected of being owned by Jews and not selling its chametz before Passover. This would mean that one could not buy chametz even from Gentile-owned stores that likely purchased their own stock of chametz from (erev) Pesach onward from these Jewish distributors.
Nonetheless, I'm aware of at least one Orthodox community that publishes lists of chain-stores that one can acquire chametz from immediately after Pesach (e.g. Costco). Is this because they are not concerned about the Jewish-distributor issue or could they have ascertained that these chains don't acquire chametz from this suspectedly Jewish distributor. Keeping in mind that chametz she'avar alav hapesach is only forbidden at a Rabbinic level and we do have a general (albeit seemingly limited in its actual customary application?) rule that rabbinic uncertainties are resolved toward leniency, could this be the deciding factor?
I'm curious to know if people have reliable sources or hearsay regarding different observant community's practice regarding this issue. Is it an issue split along modern orthodox (e.g. the aforementioned community I mentioned is affiliated with Yeshiva University's medical school) vs. Charedi communities (e.g. I originally heard of the issue at a "black-hat" synagogue in Monsey)? Are there available rulings/halachik discussions e.g. online? Could the lenient view be one limited to a shaat hadechak (hardship) type of exemption? Below are excerpts of emails from 2 synagogues about the same merchants.
From the Einstein Shul in the Bronx:
Below are details about the chametz sold in stores in our area. Please be aware that this list is not exhaustive and feel free to call or email regarding any questions.
The stores below are either owned by non-Jews or sold their chametz during Pesach.
One can purchase all chametz from stores under the Va'ad of Riverdale
All food in Big Deal Supermarket is fine.
Purchasing food from Fairway is fine as well.
Supermarket Chains/Drug Stores/etc.:
A&P Costco CVS Dunkin Donuts The Food Emporium Garden Gourmet Pathmark Shoprite- in New Rochelle Stop and Shop Superfresh Trader Joe’s Walgreen’s Waldbaum's Stores
Key Food- It is absolutely permitted to purchase any product from Key Food. However, there is some question regarding this store since despite being non-Jewish owned its main distributor is Jewish owned. If one wishes to be strict regarding this matter, this "concern" only exists until all the chametz owned over Pesach was sold. This appears to certainly occur by Shavuot and possibly earlier.
Fresh Direct- It is absolutely permitted to purchase any product from Fresh Direct. However, there is some question regarding this store since, despite selling its chametz it remains open throughout Pesach. If one wishes to be strict regarding this matter, this "concern" only exists until all the chametz owned over Pesach was sold. This appears to certainly occur by Shavuot and possibly earlier.
From a shul in Monsey:
The following stores are acceptable for purchasing chometz: BJ’s, CVS, Duane Read, Rite Aid, Sam’s Club, 7-Eleven, Trader Joe’s, Walgreen’s, Walmart and Wegman’s.
Shoprite is judged on an individual store basis. The Shoprite in Tallman is assumed to be a problem. Pathmark, Target, Stop and Shop, Costco, and Fairway are assumed to be a problem. At these stores, one should not purchase overt chometz, which includes wheat and oat based cereal, cookies, crackers, pretzels, grains, and flour. Products which contain vinegar such as mayonnaise, ketchup, and mustard may be purchased since most domestic vinegar is not chometz, and the alcohol is corn based. We recommend waiting until Lag Bo’omer, to purchase Chometz.
This list will be updated as new information becomes known.