Tortillas on the comal

How to tell it is going right

• It puffs. On the second turn the tortilla lifts into a dome as the trapped water flashes to steam and splits the two faces apart; a tortilla that never puffs was pressed too thick, cooked too cool, or turned too often.
• Freckled, not blackened: small brown spots across a pale field. An evenly browned tortilla has been on too long and will be a cracker by the time it reaches the table.
• It folds without cracking while warm, and still folds after five minutes under a cloth. A tortilla that splits along the fold has lost too much water on the comal.
• The edges are unbroken and roughly round, with no ragged fringe: a fringed edge means the masa was too dry when it was pressed, and no amount of heat will fix it afterwards.
• It smells of toasted corn rather than of scorch or of raw lime. Raw lime means the nixtamal was under-rinsed; scorch means the comal was above the working heat.

Where it goes wrong The masa was too dry or the comal too cool. A dry masa cracks at the edge on pressing and cannot generate the steam that puffs it; a cool comal dries the tortilla through before the water can flash, so it leaves the heat stiff, pale and already stale.