Assembly Line

How peanut butter is made

Peanut butter is just roasted peanuts ground fine, and a small dose of hardened oil stops it separating.

stations
6
things upstream
18
raw sources
12
steps from the ground
4

The short version

Shelled peanuts are roasted in large ovens, cooled, and blanched to rub off their skins. They are then ground in mills, first coarsely and then to a smooth paste, with salt and sugar added. Many brands add a stabilizer so the oil stays mixed. The paste is cooled and filled into jars.

  1. Shell and sort the nuts

    Harvested peanuts are dried, shelled and screened. Machines and workers pull out moldy or damaged kernels, which can carry toxins.

    Goes in
    Peanuts

  2. Roast in the oven

    Dry roasting is done in a revolving batch oven or a continuous roaster. In one batch method the nuts are held at about 160 °C for roughly 40 to 60 minutes. Roasting makes the flavor and loosens the skins.

    about 160 °C for 40 to 60 minutes

  3. Cool and blanch

    Roasted nuts are cooled quickly by air so they stop cooking. Rollers and air blowers rub off the skins, and the nuts are split to remove the bitter heart.

  4. Grind the nuts

    Mills grind the nuts into a thick paste. The friction warms it, and the oil in the nuts liquefies and turns the crumbly grind into a flowing paste.

  5. Season and stabilize

    Salt and sweetener go in. Smooth conventional brands may also get hydrogenated or palm-based oil that sets and traps the peanut oil, while natural peanut butter is just peanuts and a little salt and will separate.

    Goes in
    Table saltSugarVegetable oil

  6. Cool and fill jars

    The warm paste is chilled and pumped into jars. Cooling the jar while it sits sets the stabilizer and keeps the oil in suspension.

End of the linePeanut butter

Worth repeating

  • The Aztecs and Incas ground roasted peanuts into a paste.
  • John Harvey Kellogg was issued a peanut butter patent on May 24, 1898, and he boiled the peanuts rather than roasting them.
  • In 1922 the chemist Joseph Rosefield invented a way to keep the oil from separating, using partially hydrogenated oil.

Back to the ground

Follow every input upstream and peanut butter starts as these 12 raw sources.

PeanutsRock saltSeawaterSugarcaneSugar beetWaterSoybeansRapeseedClayLimestoneCrude oilNatural gas

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Air freshener 5 stations · 21 raw sources Styrene 5 stations · 4 raw sources Vegetable oil 7 stations · 6 raw sources Dice 7 stations · 21 raw sources Prosecco 5 stations · 12 raw sources Peanuts 5 stations

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Sources

Cite this page: "How peanut butter is made." Assembly Line, 2026-11-03. https://assemblyline.org/make/peanut-butter

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