Re – question 2162 Q. The standard practice for commercially available flour is that, following mechanical cleaning of the grain, the wheat is moistened and allowed to rest while damp – this makes the bran tougher which allows it to be more completely separated from the endosperm when milled. Thus, the presumption should be that all flour purchased for home use is chometz gamur.
A. On question 2162 regarding common dry flour available in stores, that did not come in contact with water, Poskim are lenient and permit its inclusion in the chometz sale, we wrote “The above refers to the common unsupervised flour readily and ordinarily available in the market place. Although sold as always being dry, those source grains could have been made wet after harvesting by the rain in the field, or the condensation, leaking, washing etc. during storage and grinding. Therefore, the leniency for sale is required.
You are correct, normally common flour in contemporary areas is made wet when being manufactured, as is mentioned repeatedly online. To quote one source of many:
“The wheat is then conditioned to a suitable moisture content by tempering it with water and leaving it in conditioning bins for up to 24 hours. This conditioning softens the bran and enhances the release of the inner white endosperm during milling. (from flabflour.com).”
However, it is not universal. In Third World countries, from where we get shailos too, the grain may not necessarily be soaked before grinding.
Historically, when in great need, in some forlorn, remote communities without access to markets, commercial flour was used for baking matzos.
Horav Shlomo Miller’s Shlit’a opinion is that even if the wheat grains were soaked a significant time in water, they are still not necessarily chometz gomur until you actually see them ferment. The same may apply to wet flour or dough that for some reason failed to ferment and rise, (even with fermenting additives), as many a housewife or baker can attest.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller Shlit’a