My housemates saw the hechsher on a box of matzoh, and posed a question that I think I know the answer to, but I don't know why. They asked: could Wondra flour ('precooked' flour) be kosher for passover? There are a handful of reasons that could end up with Wondra flour being non-KLP, and most of them I can explain, but there are a few steps that I cannot explain, and I think the question mostly hinges on: what is the spec for what causes wheat to become matzoh (and, therefore, eligible to become gebrochts, rather than chametz, in the future)?
To be clear, Wondra flour is, apparently, "pregelatinized wheat flour" -- flour that has been pre-cooked (what is 'cooked' here?), and then ground up. I believe that the cooking process involves giving the wheat a steam bath. The result of Wondra flour is that it cannot clump (its protein content is low, and so therefore it cannot meaningfully create gluten structures).
Here are the halachic questions that I have associated with this, and where my understanding ends.
- The flour could fail to be KLP due to a lack of rabbinical supervision to begin with. Let's assume that the input flour to this process is KLP, and has not touched water from harvest to the beginning of this process.
- The next question is: is steam water? How much steam is water? If steam is not water, then it doesn't matter: the flour is still flour -- neither chametz nor matzoh, for our purposes.
- Let's assume that steam is water. The 'cooking' process could take more than 18 minutes from the time the steam first touches it. If so, then this Wondra product is clearly sunk: it's chametz.
- But what if the cooking process takes less than 18 minutes? Is the the Wondra considered to be matzah in such a case? If so, it can then be ground up and freely re-added as gebrochts. I think this is the core halachic question I have: what is necessary for wheat and water to be considered matzah?
My interpolation from my understanding of halacha is probably that this is the point at which the intent and results would come in to play. The fact that Wondra cannot be used to make cakes is an indication that Wondra probably could be made in a KLP fashion, if it could be made in 18 minutes.