How tortillas are made
Corn tortillas start with corn cooked in limewater, a trick the Aztecs' ancestors worked out long ago.
- stations
- 7
- things upstream
- 30
- raw sources
- 12
- steps from the ground
- 9
The short version
For corn tortillas, whole kernels are cooked in limewater, a treatment called nixtamalization, then ground into masa dough. Factories press or sheet the masa into rounds and pass them through a long oven. Flour tortillas skip the limewater and are pressed from wheat dough with shortening. Both are cooled and bagged.
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Cook the corn in limewater
Whole kernels are heated in an alkaline solution of calcium hydroxide, then steeped overnight. The treatment loosens the hulls, softens the kernels and has the largest impact on the final product.
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Wash off the hulls
The cooking liquid is drained away and the swollen kernels, now called nixtamal, are rinsed. Hulls and excess lime wash away with the water.
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Grind to masa
Stone or rotating mills crush the nixtamal into a sticky dough called masa. Some factories dry and grind the nixtamal into masa harina flour, which can be rehydrated at any plant.
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Sheet and cut the rounds
Masa is pushed between rollers into a thin sheet, and a rotating cutter stamps out circles. Scrap dough is returned to the start of the line.
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Bake on stacked belts
Rounds ride through a gas-fired oven on stacked conveyor belts and drop from one belt to the next, which flips them so both sides cook. The rounds puff slightly and pick up their brown spots.
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Cool before sealing
Tortillas cool on a long conveyor so steam does not condense inside the bag and encourage mold. They are stacked, counted and bagged.
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Press the flour version
Flour tortillas are made from wheat flour, water and shortening. Most are hot pressed, which makes an irregular, strong disk. The rest are die-cut for a perfectly round, drier product.
Goes in
Worth repeating
- Nixtamalization was first done with wood ash before lime took over.
- Remnants of a comal and processed lime from around 700 BC have been found at Chalcatzingo.
- Tortillas lack the amino acids lysine and tryptophan, so they are often fortified.
Back to the ground
Follow every input upstream and tortilla starts as these 12 raw sources.
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Sources
Cite this page: "How tortillas are made." Assembly Line, 2026-11-03. https://assemblyline.org/make/tortilla