It never ceases to amaze me how few people read the Torah, as opposed to glancing through it. We’ve seen a great squabble in the Knesset over the sale of leavened bread on Pesach. Everyone firmly believes that leaven is prohibited on Pesach. Really?

Then how comes that wine is allowed? Wine is the ultimate hametz (leaven) as it is made through the process of leavening: fermentation. The ancients used wine and beer as fermenting agents. There is a commandment to eat unleavened bread, but no commandment to drink wine. All leaven must be removed from the houses.

Is leaven prohibited on Pesach?

The matzot are as leavening as any other bread. In antiquity, the crumbs of old bread were used for leavening, as housewives empirically discovered them to contain yeast. But matzot contain the very same yeast after a few days in the open air with any degree of humidity. Just like any other bread, crumbs of old matzot can be used in dough to jump-start leavening.

During Passover in Egypt, Jews prepared dough in the regular way. There is not a hint of it being any different from any other day’s dough. It was prepared in the regular dishes—not the sterile-for-Pesach utensils. The dough was prepared as usual—that is, with crumbs of old bread. The dough was there the next day (Exodus 12:41) when we left our houses; therefore it was prepared the previous evening, as is customary in the Middle East to this day. From the time of kneading until taking the dough out of houses, many hours have passed; compare with the modern eighteen-minute cutoff for the matzot dough.

Jews took the dough on the march, and carried it in overcoats upon our shoulders (Exodus 12:34). Now imagine those clothes: damp from sweat, heated by sun, infested with fungi. That was the perfect medium for leavening. How ridiculous it is to emulate that with sterile utensils cleansed of the microscopic traces of leaven.

We baked this dough on the way from Raamses to Sukkot. Even though Mechilta is adamant that the trip was miraculously fast, it still took a considerable time, as Jews had enough time to bake bread during the march. So the dough was leavened by then.

So, what is the prohibited hametz? The word “hametz” is commonly interpreted as “leaven” or “leavened product.” The first reading is nonsense: the concept of leaven only appeared two centuries ago. Before then, there was no specific leaven: bakers commonly used old crumbs to achieve leavening. The second reading is also impossible, as other leavened products such as wine were allowed.

Reading “hametz” as “leaven” makes no sense in Exodus 12:39: “They roasted dough because it was not leavened.” And if it were leavened, shouldn’t we roast it?

The etymological meaning of “hametz” is straightforward: hm for “hot” and mtz for “pressed.” There is no connotation of leavening: hametz is just any baked bread. Contrast matzah, “pressed” bread, which was afh, roasted. So matzot are flat sun- or coal-roasted bread.

The traditional interpretation of hametz as leaven developed from the fact that baked bread was normally leavened. Sun-roasted bread was made quickly, thus unleavened. Eventually, however, Jews developed a habit of baking non-leavened dough on Pesach, which is contrary to the Torah’s injunction. At Pesach, we imitate the hurry of the Exodus, and therefore symbolically roast matzot quickly rather than slowly baking bread.

The three major festivals include dramatic reenactment of the relevant events. On Sukkoth, Jews lived in ad hoc houses, the tents (they did not just eat there as the custom has it). On Shavuot, they had ad hoc festive meals prepared near the Temple rather than at home. On Pesach, Jews eat ad hoc bread: sun-dried or made on the open fire rather than in an oven. Factory-made matzot or any other unleavened flour products such as spaghetti are unacceptable for Pesach. Moreover, the Torah bans bread as such without mentioning what it is made of; soy flour bread is also unacceptable. Just like every Jew has to make a tent on Sukkoth and an outdoor meal on Shavuot, so he must roast bread on Pesach.

To make matzot, take any dough and roast it in the sun or on an open fire. The prohibited hametz is not leavened bread, but any baked products.