Working with masa

How to tell it is going right

• Pinch a small piece and roll it closed between finger and thumb: hydrated correctly the edge stays smooth and seals over on itself; a fringe of fine cracks opening along the pinched edge is under hydration, and every piece off that batch will split at the rim. In the hand it feels soft and yielding and leaves a matt film on the palm, never a wet skin that strings when the hand lifts away.
• After the rest it is damp and matt right through, and it has been kept covered the whole time: a pale dried skin over the mass, or grit that grinds under the thumb when a ball is squashed flat, means it stood open to the air or was shaped before the moisture had reached the centre of the ground grain.
• It lifts off the press as one clean piece, the rim unbroken and the thickness even from side to side at roughly 2 mm, and a hand shaped piece is judged the same way, with no thin translucent windows worn through the middle. A lacy scalloped rim, or a piece that stretches and tears as it is lifted, fails the mark.
• Held to the face it smells of toasted sweet corn, faintly mineral and clean. A sharp chalky or soapy smell of raw lime, or a bitterness sitting at the back of the tongue when a raw pinch is tasted, means it was under rinsed and no amount of heat afterwards will drive it off.
• On a surface holding 190 to 200 C (375 to 390 F) it lifts and balloons across most of its face on the last turn, then settles soft and pliable as it cools. Rested a minute and folded in half, it creases without splitting: a piece that never lifts, or that cracks white along the fold, is failed however good its colour.

Where it goes wrong Too little moisture worked in, and no rest to let what there is reach the centre of the ground grain: it handles well while it is being mixed, then tightens as it stands, so the pieces come off the press with cracked scalloped rims, sit flat and pale on the heat and never lift, and go stiff within a minute of coming off, breaking along the crease instead of folding.