Nixtamalization: how to make a proper tortilla

It’s surprising how much you have to do to corn (essentially the same as sweetcorn but more mature and dried) before it can be ground down and eaten. And with the amount of chemistry behind the process, it’s even more surprising that there’s evidence of it being used as far back as 1500BC in Mexico. The kernels need to be cooked and then steeped in an alkaline solution, which was traditionally made from mixing water and ash together but now comes in the form of slaked lime, or calcium hydroxide. This dissolves the tough, indigestible husk, paving the way to nutrients and goodness within – a process known as nixtamalization.

‘There are four different variables to keep in mind,’ says Chris. ‘The amount of water, the amount of corn, the amount of calcium hydroxide and the amount of time you cook it for. You can cook it for a long time and then just let it steep for a little bit, or cook it briefly and then let it steep for ages. What you’re after is the perfect texture for making masa, which is the dough that gets turned into tortillas.’

Once the kernels have lost their outer husk and have been given a good wash, they’re technically known as hominy, which is used in cooking throughout Latin America and places like the West Indies. But the kernels at Breddos are destined for tortillas – and there’s much more to it than just blitzing them up in a blender.

‘In Mexico they use something called a metate, which is a long flat pestle and mortar made from volcanic stone,’ explains Nud. ‘You see these ladies just sitting there for hours rolling the corn back and forth until it’s completely ground down. Obviously, we don’t have time to do that in the restaurant, so we looked at other options. We tried using a meat grinder, a Thermomix, but nothing worked. The only thing left to do was get a proper Mexican corn grinder.’

The grinder is a sort of mechanised metate – the nixtamalized corn is fed into the path of two wheels made from volcanic stone, which pulverise the kernels into finely ground masa. There’s a tap which allows more water to be added if the mixture is getting dry, and the dough collects in the bottom, ready to be shaped into tortillas.

The process sounds simple enough, but getting your hands on one of these machines outside of Mexico isn’t easy. ‘Chris drove all the way to Hamburg to collect the grinder, and we had to rewire it when we got it back to the restaurant,’ says Nud. ‘Then when we turned it on we realised the stones were rotating in the wrong direction, so we had to take it all apart and figure that out, with absolutely no instructions. But when we finally got it right and produced our first proper masa, it was a joyous moment.’

Chris and Nud found a second machine which then takes the masa and feeds it through a press, cutting perfectly round tortillas ready to be cooked on a plancha or flat griddle. This was the end of their quest to find a way of making their own homemade tortillas from scratch in the UK – one of only four or five restaurants in the whole of Europe to do so. But one question remains: why? The pair reckon it costs them about 8p to make every tortilla, but they could buy them in for 6p, eliminating the hassle working with temperamental Mexican machinery can bring. Why go to all the effort for an ingredient that most people see as secondary to the taco filling?

‘The ones we could buy just aren’t the same,’ says Nud. ‘It’s like restaurants that bake their own bread – it always tastes better. But we’re going one step further and essentially milling our own flour. It is hard, and we have to buy the corn in bulk so we have about two tonnes of it stored away in Dalston, but it is all worth it in the end.’

‘There’s always a bit of faffing about when you set up the machine, and you have to keep an eye on how wet or dry your mixture is while it’s working,’ adds Chris. ‘But there’s just no substitute – you can’t even buy in frozen masa because the ice crystals build up and make the tortillas brittle.’ And if you ever go to eat at Breddos Tacos and taste the tortilla for yourself, the proof is in the eating – the intense, corny taste and rough, pliable texture really does put it in another league compared to pretty much every other taco around. And as Chris continues to tinker with his grinder, he can – at the very least – be safe in the knowledge that the round-trip to Hamburg was definitely worth it.