Can I substitute pickling lime, slaked lime, or quicklime for Cal?

Pickling lime sold for canning in the U.S. is the same compound (calcium hydroxide) as Cal, and it works for nixtamalization at the 1 percent ratio. Slaked lime is another name for the same compound and is also fine. Quicklime (calcium oxide) is a different chemical, exothermic when added to water, and not safe for home nixtamalization. If your bag does not say food grade or pickling lime, do not use it.

How much Cal per pound of corn, in different units?

The 1 percent ratio works out to roughly 1 tablespoon (4 to 5 g) of food grade Cal per 1 lb (454 g) of dried corn, dissolved in 2 quarts of water. Scale linearly. For a 5 lb starter kit, use 5 tablespoons (about 22 g) in 10 quarts of water.

How long does the overnight rest actually need to be?

8 to 12 hours is the standard window. 6 hours can work for newer corn at higher Cal, but the flavor will not develop fully. Past 14 hours in warm weather (above 75 F) the rest can drift into mild fermentation, which gives a sour edge that some home cooks accept and some reject. Overnight in a covered pot at room temperature is the easy default.

Can I nixtamalize in a pressure cooker or Instant Pot?

You can, and many tortilleria operators do. The principle is the same. The Cal cook compresses to about 15 minutes at high pressure, after which you still let the corn rest overnight at room temperature. The rest cannot be rushed because the chemistry happens at the molecular scale across many hours, not at the heat level. Pressure cooking saves stovetop time, not total clock time.

Can I nixtamalize with masa harina instead?

No. Masa harina is the dry powder made by industrial nixtamalization, drying, and grinding. It is the finished product, not the raw ingredient. If you have masa harina you can rehydrate it for tortillas, but you will not get fresher nixtamal flavor from it because the alkaline cook already happened upstream.

Is the nixtamal water (nejayote) reusable or compostable?

Nejayote is mildly alkaline and rich in dissolved pericarp pigments. It is not directly reusable for a second batch because the Cal has been spent. It can be poured down the kitchen drain in normal home volumes. Some traditional Mexican cooks use a small amount of nejayote to season black beans, where the alkalinity helps soften the bean skin. Composting in small amounts is fine, but do not pour it on plants you care about because the pH can run as high as 11.

Why does my masa from fresh nixtamal taste better than masa harina?

Fresh nixtamal retains volatile aromatic compounds that vanish during the industrial drying step that turns nixtamal into masa harina. Side by side, fresh nixtamal masa tastes more vegetal, slightly sweeter, and more deeply of corn. The trade is shelf life. Fresh masa keeps a few days in the refrigerator. Masa harina keeps a year on the shelf.

Can I scale this up for a tortilleria or restaurant?

Yes. The ratios scale linearly to commercial volumes. Tortillaworld sells food grade Cal for individual home use and supplies tortillerias and tortilla manufacturers in larger quantities. If you need bulk corn or bulk Cal for a commercial operation, contact us and we will quote 25 lb wholesale corn and larger Cal portions. Tortillaworld has been supplying authentic dried Mexican corn to commercial kitchens Since 2012.

A hand holding a wooden spoon piled with freshly nixtamalized yellow corn kernels above a deep stainless steel pot of milky calcium hydroxide cooking water, soft steam rising in a warm sunlit kitchen

How to Nixtamalize Corn at Home

Name: How to Nixtamalize Corn at Home
Prep time: 15 min
Cook time: 2 h 30 min
Total time: 12 h 45 min
Yield: About 3 lb cooked nixtamal (7 cups) per 1 lb dried corn
Cuisine: Mexican
Ingredients: 1 lb dried whole corn (white, yellow, blue, red, or cacahuacintle); 1 tablespoon food grade Cal (calcium hydroxide), about 4 to 5 g, the 1 percent by weight ratio; 2 quarts water for the alkaline cook; Additional fresh water for the rinse and the optional final cook

May 6, 2026

Nixtamalization is the ancient Mesoamerican process of cooking dried whole corn with an alkaline solution, traditionally calcium hydroxide (called Cal in Spanish, also sold as food grade lime). The alkaline cook softens the pericarp, releases bound niacin, develops the deep corn flavor that defines real masa, and is the step that turns a hard kernel into the soft, flowered hominy you spoon into a pozole or grind into tortilla dough.

If you want the longer history and chemistry, our companion guide on what is nixtamalization covers the full theory. This guide is the recipe form. By the end you will have a pot of fresh nixtamal at your stove and a clear sense of what to do with it next.

In This Guide

What You Need
The Two Ratios You Should Not Improvise
Step by Step Nixtamalization
What Success Actually Looks Like
What Can Go Wrong, and How to Fix It
How to Store Fresh Nixtamal
From Fresh Nixtamal to Your Dish
What Corn to Start With

What You Need

The recipe is shorter than people expect. Three ingredients, one pot, and patience.

Dried whole corn. Pick a variety that fits your dish. White and yellow corn for tortillas and tamales. Blue or red corn for color and flavor in tortillas. Cacahuacintle (giant kernel heirloom) for pozole. Tortillaworld stocks all four colors plus the heirloom in non GMO and USDA organic forms.
Food grade Cal (calcium hydroxide). Also labeled pickling lime in some U.S. supply chains, though food grade Cal sold for nixtamalization is the safest pick. Tortillaworld food grade Cal is sold in a 6 oz bag, enough to nixtamalize about 12 lb of corn at the standard ratio.
Water. Filtered or tap, your call.
Equipment. A stainless steel or enameled pot large enough to hold the corn submerged in twice its volume of water. Avoid raw aluminum, which reacts with Cal. A wooden spoon, a fine mesh sieve, and a pair of cooking gloves for the rinse step are all helpful but not strictly required.

First time? The starter kit format we sell for the organic white corn nixtamal starter kit bundles 5 lb of corn plus a measured Cal portion in one box, which removes the math entirely.

The Two Ratios You Should Not Improvise

Two ratios decide whether your nixtamal turns out properly. They are short, well documented, and worth memorizing.

1 percent Cal by weight of corn. For every 1 lb (454 g) of dried corn, dissolve about 1 tablespoon (roughly 4 to 5 g) of food grade Cal. This is the long standing industry and home cook standard, used in commercial tortillerias and cited in Diana Kennedy's "The Cuisines of Mexico" (Harper and Row, 1972) and Rick Bayless's "Authentic Mexican" (William Morrow, 1987). Push above 1.5 percent and the corn turns soapy and faintly bitter. Push below 0.5 percent and the pericarp does not slip cleanly.
2 quarts of water per pound of corn. The corn needs to stay fully submerged through both the alkaline cook and the overnight rest. If your pot is shallow and the corn floats, add another quart.
Yield. 1 lb of dried corn produces roughly 3 lb of cooked nixtamal, which is about 7 cups by volume. That is enough for 4 to 6 servings of pozole or about 24 to 30 corn tortillas at the small Mexican size.

If you want to scale up, the ratios hold. 5 lb of dried corn takes about 5 tablespoons (about 70 g) of Cal in 10 quarts of water.

Step by Step Nixtamalization

Corn simmering in milky cal water on a stainless steel pot

Corn simmering in cal water. The water turns milky white as the alkaline activates.

Active hands on time is under 30 minutes total. The clock time is 12 to 14 hours because of the overnight rest. Plan the cook for an evening if you want fresh nixtamal by lunch the next day.

Rinse the corn. Pour the dried kernels into a large bowl or directly into the cook pot. Cover with cold water, swish with your hand, and pour off any floating chaff or debris. Repeat once. Pick out any stones or split kernels. The water should run mostly clear before you move on.
Dissolve the Cal. Measure your Cal into a small bowl. Add a few tablespoons of warm water and stir until the powder dissolves into a milky slurry. Pour the slurry into your cook pot. This step prevents the Cal from clumping at the bottom of the pot and scorching when the heat comes on.
Cook with Cal for 30 to 60 minutes. Add the corn and the rest of the water to the pot. Bring to a low simmer, never a hard boil. Stir every 10 minutes or so. After 30 minutes, lift one kernel out with a spoon and rub it between your fingers. The pericarp (the outer skin) should slip off cleanly. If it does not yet, simmer another 10 to 15 minutes and test again. Older corn takes a touch longer. White and yellow dent corn typically slip at 30 to 45 minutes. Blue and red landrace varieties can take closer to an hour. Cacahuacintle for pozole is similar to dent.
Rest overnight, 8 to 12 hours. Pull the pot off the heat the moment the pericarp slips reliably. Cover with a lid and let the corn rest in the alkaline water at room temperature for 8 to 12 hours. This is when the chemistry actually finishes. The kernel hydrates, the niacin liberates, and the corn flavor deepens. Do not skip this rest. A 30 minute boil with no rest produces undercooked, bitter nixtamal.
Rinse thoroughly. The next morning, drain the corn into a fine mesh sieve or colander. Run cold water over the kernels and rub them between your hands. The pericarp will slough off as a thin yellow cream and float away with the rinse water. Rinse until the water runs clear and the kernels feel firm and clean. This is the most physical step. A pair of cheap food gloves saves your fingertips. The cooking water you pour off, called nejayote in Spanish, is mildly alkaline. Pour it into the sink, not onto plants you care about.
Final cook (only if you are eating it whole, as in pozole). If your destination is pozole, return the rinsed corn to a clean pot, cover with fresh water, and simmer until the kernels flower and become tender, about 1 to 2 hours depending on the age of the corn. The kernels burst open like little popped popcorn, the visual signature of a proper pozole. If your destination is masa for tortillas or tamales, skip the final cook. Rinsed nixtamal goes straight to the molino or the food processor for grinding.

What Success Actually Looks Like

You can read about nixtamalization for an hour and still not know whether your batch is right. Three checks are reliable.

The pericarp slips. Rub a kernel between your fingers under cold water. The thin yellow skin should peel back cleanly. If it clings, the corn needs more cook time or a longer rest.
The kernel is hydrated, not raw. Bite a rinsed kernel in half. The interior should be uniformly white or matching the corn color, soft enough to bite through with mild pressure, with no chalky core in the center. A chalky core means under cooked. Return it to the pot for another 30 minutes of rest in fresh warm water and check again.
The smell is clean and slightly sweet. Fresh nixtamal smells like wet corn and a faint hint of lime, not soap and not sour. A soapy smell points to too much Cal. A sour smell points to a rest that ran past 14 hours in warm weather. Both are recoverable in small batches by extending the rinse, but they are signs to adjust next time.

What Can Go Wrong, and How to Fix It

Pericarp will not slip after 90 minutes of cooking. Either the corn is older than expected or your Cal is past its useful life. Cal that has absorbed humidity loses alkalinity. Open a fresh bag and try again. If the corn is the issue, rest it overnight as planned, then re cook in fresh water with another 0.5 percent Cal the next morning.
Kernels are mushy. Over cooked, usually because the simmer turned into a boil. Drain immediately, rinse, and use it for posole or for tamale masa where soft texture is welcome.
Soapy taste. Too much Cal. Rinse the corn 3 or 4 times instead of once. The taste mostly washes out.
Sour smell after the rest. Rest ran too long in warm weather, or pot temperature dropped slowly enough that fermentation started. Rinse aggressively, then proceed. The fermented note will fade in the final cook for pozole, or in the masa cook for tortillas.
Yellow water that will not run clear. Normal. The yellow color is the dissolved pericarp pigment. Once the kernels feel clean to your hand and the water has lightened, you are done rinsing.

How to Store Fresh Nixtamal

Fresh nixtamal is a perishable product. Treat it like cooked rice or cooked beans.

Refrigerator: 4 to 5 days in an airtight container, fully drained. The kernels will firm up slightly. Refresh with a 5 minute warm water bath before grinding into masa or simmering into pozole.
Freezer: up to 6 months. Drain, spread on a sheet pan to flash freeze for an hour, then transfer to a zip top freezer bag. Frozen nixtamal grinds into masa straight from the bag with no thaw step. For pozole, thaw in the refrigerator overnight before the final simmer.
Do not store in the alkaline rest water. Once the rest is done, rinse fully. Storing in nejayote leaves a soapy taste that grows over time.

From Fresh Nixtamal to Your Dish

Once you have fresh nixtamal, the next step depends on the recipe.

Corn tortillas: grind the rinsed nixtamal into masa, press, and griddle. Our step by step guide on how to make corn tortillas from scratch with real corn walks through the press and griddle method.
Tamales: grind into a slightly coarser masa, beat with lard or shortening until light, fill, and steam. See how to make tamale masa from real corn.
Pupusas: grind into masa, form into thick rounds, stuff, and griddle. See how to make pupusas with real corn masa.
Pozole: simmer the rinsed nixtamal in fresh water until the kernels flower, then build the broth around them. The full method for cacahuacintle pozole rojo is in our cacahuacintle corn for pozole guide.

What Corn to Start With

Five varieties of dried corn: white, yellow, blue, red, and cacahuacintle

Five corn varieties Tortillaworld stocks. The right corn depends on the dish, not the price.

Tortillaworld has been supplying authentic dried Mexican corn to home cooks, restaurants, and tortilla manufacturers Since 2012. The right corn for your first batch depends on the dish, not on price.

Tortillas (everyday use). Start with 5 lb of non GMO white corn or non GMO yellow corn. White produces the pale, pliable tortilla you see at most Mexican tables. Yellow gives a richer color and a fuller corn flavor.
Tortillas (color and depth). Non GMO blue corn for the deep blue gray tortilla with a slightly nuttier flavor. Ruby Red heirloom corn for a deep brick red tortilla with floral notes.
Pozole. Cacahuacintle giant heirloom corn is the traditional pick. The flowered kernel is the visual signature of pozole. Read our cacahuacintle guide for the full pozole rojo method.
Tamales. White or yellow corn is traditional. See how to make tamale masa from real corn for the whipped masa preparada method.

Yield Reference

1 lb of dried corn produces about 3 lb of fresh nixtamal, which is enough for roughly 24 to 30 corn tortillas at the small Mexican size, or 4 to 6 servings of pozole, or about 12 to 16 small pupusas.