We have seen that we do our utmost to ensure that the dough does not become chametz. This starts with the water being drawn at a specific time of the day to ascertain that the water is not warmed, known as ma’im shelanu. Similarly, we do not use freshly ground flour, which can still be warm, and the sacks of flour are kept in a cool place. Once the flour is mixed with the water, we keep it away from the sun.
And even after the dough finally makes it safely into the oven, the concerns are not yet over. If during the baking, the matzah develops bubbles (known as nefuchos) or becomes doubled over (known as kefulos), there is a concern that it was not fully baked on the inside, and it may become chametz.
If someone pulls out the matzah and is not sure if it is baked through and through, the rule of thumb is that if the matzah is pulled apart and there are no strings, or if it is brown (karmu panehah), we can be sure that it is entirely baked. However, if the matzah was pulled out too early, and it was not fully baked, putting it back in the oven can still be a problem. Since it already became hot, if it was not fully baked, it can become chametz very quickly.
“BISCUIT” MATZOS
There is a fascinating innovation that was the subject of a major discussion a number of years ago among the poskim, including the Eidah Hachareidis of Yerushalayim.
It is interesting to note that many great rabbis in Yerushalayim, including the Eidah Hachareidis, would use machine matzos that they considered to be top quality in taste, preparation, and kashrus.
There were certain machine matzos that were being manufactured in a way that copied the system used for baking biscuits. In order to bake biscuits properly, many varied heat levels are used, starting with low heat and then gradually using stronger heat. The question was: Can this process be used for matzos? On the one hand, it seems to help bake the matzos much more efficiently. But on the other hand, due to the way the heat is applied, there may be an issue of causing the dough to become chametz more quickly, before it is actually considered halachically baked in the oven.
IN SUMMARY
If during the baking, the matzah develops bubbles or becomes doubled over, it may not be fully baked on the inside, and it may become chametz.
If we are not sure if the matzah was fully baked, the rule of thumb is that if the matzah is pulled apart and there are no strings, or if it is brown, we can be sure that it is entirely baked.
If the matzah was pulled out too early before it was fully baked, putting it back in the oven can be a problem.
RABBI NACHUM SCHEINER
