Masa

Instructions

1. Tip 120 g of dried corn onto a tray and pick out any grit, broken kernels or chaff. Rinse under cold running water and drain.
2. Bring 1.2 l of water to the boil in a tall stainless steel or clay pot (never aluminium, which the lime attacks). Slide the heat to low and whisk in 1.5 g of cal until it dissolves and the water turns milky and slippery between the fingers.
3. Add the drained corn, bring back to a bare simmer and cook uncovered for 45 minutes, stirring now and then and skimming the loose skins that float up. It is ready when a kernel lifted out and rubbed between thumb and finger sheds its transparent skin easily but the centre is still firm and chalky, not soft.
4. Take the pot off the heat, cover it and leave the corn to steep in its lime water for 8-14 hours, or overnight. The kernels will swell, deepen in colour and take on the unmistakable nixtamal smell.