from the October 24, 2010 Newsletter issued from
Hacienda Chichen Resort beside Chichén Itzá Ruins, central Yucatán, MÉXICO
When Luis, one of the waiters, mentioned the possibility of brewing a decent coffee concocted from roasted, ground tortillas, Marcela, a visitor from Argentina, wanted to try it. I was the only one around with an appropriate campfire, so we tried it in my hut.
I built a fire, let it burn until chunky, glowing embers formed, and atop two logs put a wire mesh with some tortillas atop it. It looked like what's shown above. Notice that flames aren't lapping at the tortillas; heat from glowing embers is baking them.
Maya folk who do this in their homes roast their tortillas on a traditional comal, which is a flat, thin, metal disk suspended over flames on three rocks. We didn't have that, but our wire-mesh-over-coals technique seemed to work OK.
We made three tries at it. One attempt produced almost totally black tortillas. The black dust scraped from them made a flavorless brew tasting the way you'd expect charcoal and water to taste.
Another try with tortillas that turned out hard but only slightly browned produced a drink tasting like roasted tortillas, which wasn't bad, but there was no coffee flavor.
The best result was by slowly roasting tortillas until they were hard and brown, with only a little black charring. You can see part of such a tortilla below:
Such a tortilla crumbles easily into the bottom of a cup, then you can use something blunt to smash the crumbles into powder. The resulting powder can be used as if it were instant coffee. Add hot water, sweeten and add milk if you wish, and, by golly, if you get it right it actually has a robust coffee taste and you just sit there sipping, amazed that you've produced decent coffee from tortillas.
I've parched corn kernels in a similar fashion, with similar results, so if you don't have tortillas but do have loose corn kernel, try browning them over embers, then grinding them into a powder. Up North most tortillas sold in stores are wheat tortillas, not corn tortillas like ours. I don't know whether wheat tortillas would do or not. I suspect that roasted wheat tortillas might make a flavorful drink, but I doubt it'd taste as much like coffee as a properly roasted, corn-based brew.