To make tortillas the traditional way, first you have to cook the maize with something alkaline (cement, for instance), and then grind the wet grains by hand, kneeling on the floor with your metate. It takes about an hour to grind enough to feed one person for one day. Until fifty years ago, there was no effective widespread way to automate this process: every Mexican household would have one woman in the back room, grinding wet corn for five hours a day. Since then, things have changed—bringing great benefits, widespread social change, and some losses too
Of course, there are trade-offs. Bimbo is not as good as a bolillo. A machine-made tortilla is not anything like a homemade tortilla – it’s not even in the same universe.Mexican women that I have talked to are very explicit about this trade-off. They know it doesn’t taste as good; they don’t care. Because if they want to have time, if they want to work, if they want to send their kids to school, then taste is less important than having that bit of extra money, and moving into the middle class. They have very self-consciously made this decision. In the last ten years, the number of women working in Mexico has gone up from about thirty-three percent to nearly fifty percent. One reason for that—it’s not the only reason, but it is a very important reason—is that we’ve had a revolution in the processing of maize for tortillas
from “Fueling Mexico City: A Grain Revolution,” by Rachel Laudan, edible geography, 14 June 2010