This question is partly hypothetical. A new kosher pizzeria owned by non-observant Jews opens a few weeks after Pesach.
- Would the kashrut agency check to see that the ingredients were purchased after Pesach, therefore not being chometz sheavar alav pesach?
- If someone is unsure, can they be lenient?
- It is something that should be done, the same way the kashrus agency should check the distributors of existing stores to make sure that they are not selling the store chametz sheavar alav hapesach. If all kashrus agencies do this I don’t know. It is not hard to call the agency and ask them specifically.
- If you are unsure you may be lenient. See sources.
Lilkot Shoshanim 4 pg. 105. The reason is because there are numerous sfaikos here and safek d’rabonon lkula. First of all it could be that the chometz was by the company during pesach, and the kashrus agency sold it. Secondly, it is possible that the wholesaler sold is chometz, ( id he is dealing with religious Jews, they may not want to buy from him after pesach id he didn’t sell it). Even if he indeed didn’t sell his chometz there ae opinns that a mumar that didn’t sell his chometz that it isn’t assur after pesach, (see Magen Haelef O:CH 447-7 D:H V’od), and others that saythat the chometz of a tinok shenishba is not forbidden, ( Pri Megadim 448 M:Z-4, Haelef Lcho Shlomo -261). This is aside from other lenient factors, therefore we are not going to be stringent when it is only a safek of a knas of a d’rabobnon. Also see Aliba D’hilchoso vpl. 85- pg. 62 ftnt. 94. This is also the ruling of R’ Y. Cahen shlit”a.