Making masa harina from flint corn (nixtamalisation with wood ashes)

After meaning to for a number of years, I've finally made masa harina out of some flint corn that I grew--it is delicious! There are a few threads on making nixtamal, but I thought this would be a good new thread (plus I have pictures!)

I wanted to make masa using wood ashes rather than lime, given the relatively high energy intensity of lime (and the fact that I cannot, at present, make it myself). However, procuring wood ashes has been a perennial challenge, as I have been flatting, and many flats don't have fire places, and it has been more difficult than I anticipated getting clean ash from untreated wood. Having a South African flatmate saw us building a braai (a sort of wood-fired barbecue), which meant I could finally make some masa harina, which is otherwise difficult to procure locally as well as expensive.

A number of scientific studies exist comparing wood ashes and slaked lime for making nixtamal--these provided a range of traditional ratios of dried corn to wood ash. By weight, a common figure was 1 part corn to 0.8 parts ash. By volume, this is closer to 1 part corn to 0.5-2 parts ash. The right value likely depends on the types of hardwood comprising the ashes, as well as how long the ashes are stored. Ashes are good at binding CO2 from the atmosphere, making them less caustic over time (and why they are being used in all manner of CO2 scrubbers being devised for coal and oil plants). As my ashes were half fresh, and half a month old, I used a 1:1 ratio by volume.

I started by sifting the ashes through a fine sieve, to avoid hunks of charcoal getting stuck in the corn. To reduce cooking time, I soaked the corn in ash water overnight to hydrate it. I only had to boil it for ~20 minutes before the corn was fully cooked and smelled of delicious tortillas. After it cooled, I returned the corn and ash water to its original jar and let it sit overnight. I had heard a lot of bad things about washing the ashes out of the corn, but it was pretty easy--put it all in a bowl of water and just pull out the kernels with a slotted spoon, or even your hands. Do this a couple times--use a sieve or colander or whatever is to hand to help out. My end result had virtually no grit from the ash. As a bonus, the wash liquid can be applied (sparingly) to brassicas, tomatoes, and root vegetables, which need lots of phosphorous, potassium, and calcium.

The kernels were very tasty as-is at this point, but I wanted to make masa harina so I could make tortillas later. As I was concerned that the kernels might not dry very quickly whole, I ran the lot through my mincer, then spread it on the dehydrator's trays. Worked a treat, and was easy to grind afterward! I really like this methodology, as it circumvents the use of industrially produced lime and significantly decreases the cook time of the corn. The wash water, being reduced significantly of its caustic power is useful afterward in the garden rather than as a weed killer--what's not to love?

Here's the short version--low-energy masa harina

Place 2c of flint corn into a jar with 2c finely sifted wood ash

Fill with water and soak overnight

Boil corn-ash mixture until corn is fully cooked (20 min in this case)

Return to jar and let sit for 24 hours

Wash corn 2-4x in water, using a sieve or slotted spoon to retrieve corn from the ash-laden water. No need to remove the skins for making masa harina.

Run the masa through a meat grinder to crush it and prepare it for drying

Dry pellets in a solar dehydrator

Once dry, run through a flour mill

Enjoy your masa!

Have you tried using wood ash to nixtamalise corn? How do you like it compared to using lime? Do you make dried masa or use it fresh? Pictures of nixtamal, masa harina and home-made tortillas very welcome!

What a great process!! I just did this a week or two ago, but I used lime, not ashes. I also used a red corn and was amazed to find that it took many hours more than the usual yellow (feed) corn generally takes me. It could be that this corn was older, I suppose, I got it from a different supplier than usual.
I'm curious about the choice to grind it dry rather than wet; do you typically use small amounts? Or is it easier to get a finer grind when it's dry?
Dry grinding is an interesting option I hadn't thought of-- I generally do a kg of corn at a time, which is enough for two LARGE meals (like, hosting a dinner meals, or dinner for 4 with leftovers for two more meals), so I process it all at one and freeze half.
Thanks for the food for thought!!!

Update! Successfully used the masa to make tortillas. They came out an interesting colour, but the dough worked just as I remember, and they were very tasty!

Tereza Okava wrote:What a great process!! I just did this a week or two ago, but I used lime, not ashes. I also used a red corn and was amazed to find that it took many hours more than the usual yellow (feed) corn generally takes me. It could be that this corn was older, I suppose, I got it from a different supplier than usual.
I'm curious about the choice to grind it dry rather than wet; do you typically use small amounts? Or is it easier to get a finer grind when it's dry?
Dry grinding is an interesting option I hadn't thought of-- I generally do a kg of corn at a time, which is enough for two LARGE meals (like, hosting a dinner meals, or dinner for 4 with leftovers for two more meals), so I process it all at one and freeze half.
Thanks for the food for thought!!!

It might be age, but this corn was something I harvested from my garden 4-5 years ago, and it cooked up very quickly with the pre-soak step. I had delayed so long as I wasn't sure I'd do it properly, so it sat in a jar for all those years and 5 house shifts. We nixtamalised two cups of corn, and used one cup here; there's just two of us, so we don't use a massive amount at any given time (unless I'm making tamales, then all bets are off!).

Drying it has the following benefits:

Shelf-stable storage (not taking up valuable freezer space--a real consideration when flatting with other people as I am)

I can use my existing grain mill to grind the masa (I don't have a metate, and haven't even seen one in this country yet)

The grind is finer than grinding wet in a mortar and pestle or blender. I found it to be a similar grind to the imported masa I can purchase

Dry masa allows fine control of how hydrated the corn is, making it easier to make tricky things like tortillas (not as necessary for tamales)

Well done. Those tacos look awesome!

I have done a couple of batches using wood ash, and although it worked well the flavour just didn't push the same buttons that I grew up with in the borderlands, so I do all my nixtamalising with hydrated lime now. Since I get a 20kg bag of lime about two or three times a year to make mortar, plaster and other things, we always have it (or lime putty) on hand.

We also don't go to the trouble of the drying and secondary grinding, but that sure does turn out a nice looking product. Our tortillas have a very "handmade" look when I just press them from wet-ground masa.

Now that I have got a good line of 8-row corn going, I want to do more of my ancestral Haudenosaunee foodways, like corn soup. That would take me back to using wood ash in the interest of tradition. But for tortillas and arepas, I'm on Team Lime.