How cotton candy is made

Cotton candy is sugar melted and flung through a spinning screen, where it freezes into hair-thin strands in midair.

stations: 9
things upstream: 57
raw sources: 17
steps from the ground: 11

The short version

Floss sugar, treated to form fibers and blended with dye and flavor, falls from a hopper into a spinning heated cylinder with holes in its side. Molten threads fly out and harden in a surrounding pan. A carnival operator twirls them onto a cone, while a factory machine rolls them into a block, slices it and seals the pieces in bags.

Tint the floss sugar

The sugar is specially treated to form fibers. Federally regulated dyes and natural or artificial flavors go in, because plain sugar spins out white.

Goes in
Sugar
Load the hopper

Sugar goes into a large stainless steel hopper. Its tapered bottom funnels the granules down into the extruder, a metal cylinder with holes along its sides.
Melt in the cylinder

A heating element inside the extruder turns the granules into a thick, sticky liquid. Crystal size matters, since very fine sugar can fly out unmelted.
Fling through holes

The cylinder spins and throws liquid sugar out through its holes in every direction. It leaves as threads many times thinner than a hair.

3,450 revolutions per minute
Catch the cooling strands

Threads turn solid as they leave and land in a wide circular pan. Air trapped between them gives the fluff. Plants keep moisture low here, or the strands clump together.
Gather onto cone or belt

At a carnival, the operator circles a cardboard cone around the pan and the sticky strands cling to it. Automated machines pull them onto a conveyor instead.
Roll into a block

Non-stick rollers above and beside the belt shape the bundle into a continuous block of fixed height and width. They press gently, because too much force changes the texture.
Slice into segments

A vertical knife slides down through the moving block at set intervals, then retracts. Another roller presses each segment back into shape.
Bag against moisture

Each piece is sealed in a plastic bag, since water vapor turns the candy rubbery and sticky. Bags get a date and batch code, then go into boxes. Sealed well, it lasts about six months.

Goes in
Plastic bag Cardboard box

End of the lineCotton candy

Worth repeating

The machine was invented in 1897 by a dentist, William Morrison, and a confectioner, John C. Wharton.
At the 1904 World's Fair the candy, then called Fairy Floss, sold 68,655 boxes.
Mass production waited until 1972, when an automatic machine that could also package the candy was patented.