Come sundown on Monday night, Jews all over the country will start their eight-day Passover matzo diet, and many of them will be getting their fix from the Sreit's blue box.
To meet the demand, Streit's started baking kosher for Passover matzo last September right after Rosh Hashanah. Between then and now they've produced about 2.5 million one-pound boxes, enough to meet a week's demand that nearly outpaces the non-kosher-for-Passover matzo that Jews eat during the rest of the year.
According to Rabbi Mayer Kirshner, who oversees Streit's kosher operations on a full-time basis, there are two major differences between Passover and non-Passover matzo. First, Passover matzo must be mixed and baked completely within 18 minutes in order to prevent any potential leavening. (Non-Passover matzo dough, on the other hand, can sit around indefinitely.) Second, Passover matzo dough can only contain flour and water, while non-Passover dough can include additional spices and flavorings, as well as some canola oil and malt.* Both restrictions ensure the austerity of Passover matzo and mimic the hastiness of its original mythic manufacture.
* A notable exception is egg matzo, which according to Rabbi Kirshner, is acceptable for elderly and infirm people who would have trouble digesting the standard matzo.
It all happens on Rivington Street, where the Streit's factory has been baking matzo since 1925. Take a tour of the whole operation in the slideshow.