4.The Definition of Leavening Dough
As we have learned, the difference between bread and matza is that the dough used for making bread has undergone a leavening process resulting from the fermentation of ingredients within the flour that have come into contact with water. In order to augment the leavening process, bakers customarily mix se’or into the dough, causing the dough to ferment more thoroughly and quickly. However, even without the leavening agent, if dough were left without kneading, it would ferment and rise. Therefore, when preparing matzot one must work quickly to ensure that the leavening process within the dough does not begin.
As long as the dough is in motion, being kneaded, it does not become ĥametz. Even if the kneading were to continue an entire day, the dough would not become ĥametz, since kneading inhibits the leavening process. However, if the dough sat motionless for eighteen minutes, the leavening process has begun and all the prohibitions concerning ĥametz apply to it. This applies to normal conditions, but where it is hotter, the leavening process is accelerated, and the dough becomes ĥametz in even less than eighteen minutes.
Cracks appearing in the dough are a physical indication that the dough has become ĥametz. Even if eighteen minutes without kneading had not yet passed, since there are cracks in the dough, it has certainly become ĥametz; apparently conditions were warm and so it took less time to become ĥametz. Moreover, the kneading may have been inadequate, so that certain parts of the dough were neglected, causing those areas to become ĥametz. Even if there are only a few cracks, and they appeared only in part of the dough, the entire dough is ĥametz. If no cracks appeared but the dough blanched, it is ĥametz nuksheh (hardened ĥametz; see next section), which is rabbinically forbidden (SA 459:2). 3 5.Ĥametz Nuksheh (Hardened Ĥametz)
The ĥametz that the Torah forbade is ĥametz gamur (absolute ĥametz), meaning that the leavening process has been completed, and the food has become edible. But if fermentation had begun but not concluded, and from the outset the food was barely edible, then it is called "ĥametz nuksheh." According to most poskim, ĥametz nuksheh is not forbidden by Torah law, but the Sages prohibited it so that people would not err and come to eat or keep real ĥametz.
An example of ĥametz nuksheh is the glue that scribes used to prepare from flour and water for gluing paper. Since its leavening process was never completed, and it is barely edible, it is ĥametz nuksheh, and the Sages forbade eating it or keeping it on Pesaĥ (MB 442:2). If its form was changed, as when the glue is used to stick papers together, then one is allowed to keep it. Others are more stringent and maintain that if the glue protrudes from between the pages, then it is considered as if it has maintained its same form, and it is forbidden to keep it on Pesaĥ (SA and Rema 242:3).
Similarly, dough that began to ferment to the point that its surface blanched, but the surface was not cracked as with true leavening, is considered ĥametz nuksheh, and it is forbidden by rabbinic law to eat or keep it on Pesaĥ (SA 459:2). 4 6. Ĥametz So Spoiled That a Dog Would Not Eat It
Ĥametz that was originally fit for eating, but that became moldy or spoiled to the point that it is not fit for human consumption, is still considered ĥametz gamur, since it can still be used as a leavening agent. In other words, even though, in general, all forbidden foods become no longer forbidden once they are no longer fit for human consumption, ĥametz is different. Since it can still help in the preparation of food, it is like se’or, which serves as a leavening agent and is therefore considered ĥametz. However, if it became so spoiled that it is not fit for consumption by a dog, then it is not considered food at all. Therefore, the law of ĥametz does not apply to it and it is permissible to keep it during Pesaĥ and to gain benefit from it (SA 442:2; MB ad loc. 10). By rabbinic decree, however, it is still forbidden to eat it on its own, for one who eats it – even though he is doing something very unusual – demonstrates that he still considers this ĥametz to be food (MB 442, 43).
The yardstick of being fit for a dog’s consumption is relevant only for measuring the spoilage of ĥametz or se’or. But if se’or was not spoiled, but only became so sour that it is not fit even for a dog, since it is good se’or (that functions as a leavening agent and is usable like regular yeast), all the laws of ĥametz apply to it, and one is required by Torah law to destroy it (BHL 442:9).
This law – that one does not have to burn ĥametz that was spoiled to the point of not being fit for a dog’s consumption – applies only if it became spoiled before the time that ĥametz becomes prohibited. But if it was fit to be eaten by a dog when the prohibition of ĥametz began, then even if it became spoiled later, to the point of not being fit for a dog’s consumption, one must burn it. Once the mitzva of eliminating the ĥametz is in effect, one does not discharge his obligation until he has destroyed the ĥametz completely (MB 442:9; see below, ch. 5, n. 5). 5
Note that all of these laws are conditional on the ĥametz having initially been fit for human consumption, or for preparing food for humans as se’or. If, however, it was not fit for human consumption at all from the beginning, then even if it was fit to be eaten by a dog, no prohibition applies to it. If from the beginning it was not intended for consumption, but it was in fact barely fit for human consumption, then it is ĥametz nuksheh, as described above. 7.Ways in Which There Is No Leavening
As noted, there are five types of grain that can become ĥametz after touching water. However, if they are roasted in fire, they can no longer become ĥametz, and in principle they may be mixed with water. Nevertheless, the Sages were concerned lest the roasting not be thorough, and thus the grain would become ĥametz when coming into contact with water. Therefore, one must treat them just as one treats regular cereal grains. If they became wet and eighteen minutes passed, we suspect they may have become ĥametz, and it is forbidden to gain any benefit from them, and one must destroy them (SA 463:3; MB ad loc 7).
The above concerns kernels of grain that were roasted in fire, but if it was flour that was roasted, there are Rishonim who are lenient, maintaining that one need not suspect that the flour was not roasted well. Thus, it is permissible to mix such flour with water or in a cooked food without concern for ĥametz (Rashi, Rambam). However, many Rishonim hold that in the case of flour, as well, one must be concerned that it may have not been roasted thoroughly (Rabbeinu Yeruĥam, Hagahot Sefer Mitzvot Katan, Hagahot Maimoniyot, and others). The Aĥaronim rule that one must not mix roasted flour with water or in a cooked food, lest it become ĥametz. Nevertheless, if one did make such a mixture, even though it is forbidden to eat it, it is permissible to keep it until after Pesaĥ and to eat it then (MB 463:8; Kaf Ha-ĥayim ad loc. 13).
However, concerning matza that was properly baked, it is agreed that it cannot become leavened again. Accordingly, it is permissible to soak matza and matza meal in water, and, indeed, this is what most people do. Ĥasidim, however, customarily do not eat soaked matza (see below 8:2).
Scalding the grains or the flour in boiling water also destroys the capacity for becoming ĥametz. However, the Ge’onim prohibited doing so, for today no one knows how to do this scalding, and if the boiling does not destroy the potential for becoming ĥametz, an opposite process of rapid fermentation may be generated, as heat may hasten fermentation. Therefore, scalded grains or flour are treated just like ĥametz: it is forbidden to gain any benefit from them and one must burn them (SA 454:3; MB 13).
Flour on which water dripped, drop by drop, continuously, even all day long, does not become ĥametz, since the falling of the drops disturbs the flour and shakes it, and does not allow the leavening process to develop. Immediately upon cessation of the dripping, one should knead the dough and bake it. If there is doubt that some of the dripping may not have been continuous, then this is a doubt concerning a law of Torah, and one must relate to that flour as ĥametz and burn it (Pesaĥim 39b; SA 466:6).
Another way to prevent the dough from fermenting is by soaking it in cold water (Pesaĥim 46a; SA 457:2). Preferably, one should not do so, lest the water not be cold enough, allowing the dough to ferment (Rosh, MB 454:18). 6
Flour that was kneaded with fruit juice does not become leavened at all, but if even a little water was added to the mixture, then it will become leavened (matza ashira will be explained below [8:1]).