Sean Sherman, The Sioux Chef, Makes Nixtamal with Wood Ash

So you want to nixtamalize your own corn for fresh masa, pozole, hominy stew, and other delicious applications? There are few better ways to witness the miracle of science firsthand. Without nixtamalization — or the process of cooking field corn in an alkaline solution — there is no masa, one of the foundations of Mesoamerican civilization and a bedrock of Mexican cooking. Dried corn that has not been nixtamalized lacks nutritional value, but once it has been cooked and steeped in an alkaline solution, magic happens: the corn is softened, unlocking essential amino acids and vitamins naturally found in each kernel, and creating an unparalleled flavor, aroma and texture. 

Corn before and after ash nixtamalization

Today, calcium hydroxide—also referred to as cal, slaked lime, or pickling lime—is the most commonly used form of alkali for the nixtamalization process. However, in his forthcoming book, MASA: Techniques, Recipes, and Reflections on a Timeless Staple, Masienda founder Jorge Gaviria delves deep into the history of nixtamalization, describing how wood ash has long been favored by the Indigenous tribes from the territories north of the current US-Mexico border to create the alkaline solution that can be a catalyst for nixtamalization.

“Historically, the alkali used in nixtamalization has been derived from many substances. The peoples of Mesoamerica primarily used (and continue to use) slaked lime, ash, and tequesquite, whereas those north of Mexico chiefly nixtamalized with lye made from wood ash. The Creek and Seminole, for example, employed hickory ash; the Navajo used juniper, and the Hopi fourwing saltbush, or chamiso. Ash was also used for other important purposes beyond nixtamalizaton, including teeth cleaning; slaked lime is a key ingredient in industrial building mortar and cement pastes—which, as we’ll learn later in the kernel-to-masa process, is a key binding agent in masa itself."

We were lucky enough to film a wood ash nixtamalization tutorial with Sean Sherman, also known as The Sioux Chef, the mind behind Owamni, the full-service Indigenous restaurant in Minneapolis, Minnesota, that was named winner of the Best New Restaurant of 2022 Award by the James Beard Foundation. In this video, he shows us one of the oldest methods for nixtamalizing corn, using ash from hardwood trees like birch or oak. 

Happy nixtamalizing! 

More on The History of Nixtamalization from MASA

As with corn itself, much of masa’s beginnings are a mystery. For masa, specifically, we don’t know just how long ago the beginning was, and, to date, we don’t have records of exactly how Mesoamericans conceived of such a phenomenal, brilliant food.

So far, the earliest evidence of equipment used specifically for masa making was discovered in Guatemala and dates back to 1500 to 1200 BCE. Archaeologists have additionally found earthenware colanders used to strain alkaline chemicals that date back to circa 1000 BCE. Through such archaeological evidence, we know that the Maya, Aztecs, and others incorporated alkali, a basic chemical compound, into their corn’s preparation. They would boil the alkali materials—usually in the form of slaked lime or ash derived from crushed mussel and snail shells or wood—along with the corn in a pot of water. The alkali would help loosen the hulls, or pericarp, of the maize and break down the kernels’ cell walls. This process would render the corn’s naturally occurring niacin (vitamin B3) content bioavailable, which is otherwise inaccessible to the human body. Translation: The alkali releases pretty major nutritional goodness.

This alkaline cooking process ultimately came to be called nixtamalization. This word is derived from nixtamal, a word in the Aztec language Nahuatl, which itself is a conjoining of nextli, or “ashes,” and tamalli, or “unformed corn dough.” Nixtamal is what the corn becomes and what it is called once it has undergone nixtamalization. You may also know it as hominy.” 

Does corn nixtamalized with ash taste different than corn nixtamalized with cal?

"The flavor of the finished nixtamal and masa has a distinctly smoky, campfire essence, which I find especially complements roasted vegetables and grilled fish, though any pairing works, really. There’s also something rustic, elemental, and primordial to me about this method that I find quite romantic."

How is nixtamalizing corn with wood ash different than nixtamalizing with cal?

"Clocking in at a pH of about 11.3, wood ash is more than ten times less caustic than cal, which is approximately 12.4 pH. The pH scale is logarithmic, which means that a difference of one integer value (e.g., 12 to 11) changes the concentration by a factor of 10. This means that it takes a bit more ash to get the job done than cal.

For this reason, we’ll use a ratio of 1 part ash to 1 part corn, by volume. For example, one cup of corn will require one cup of ash to get the job done. (By weight, this ratio works out to be about 1 part ash to 2 parts corn, depending on the size and density of the corn kernels used.)

Where to find ash for nixtamalizing corn:

"Because ash has common applications beyond nixtamalization, including soap making and as a soil amendment, it is easy to find sifted wood ash online, if you don’t happen to have any on hand. Alternatively, you can hit up your nearest wood-fired restaurant for some, as it’s usually thrown out at the end of an evening’s service. (Special thanks to chef Juan and Max at Gjelina restaurant for Masienda’s local ash hookup.)"

For more on masa and nixtamalization, shop the MASA book.

Cover of MASA Book by Jorge Gaviria

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