Invention blasts off our cereal business

Cheerios, as well as several other beloved cereals, wouldn’t be possible without one key invention.
puffing gun

The puffing gun

Although our founding company began in flour milling in the 1860s, General Mills is now known for many different foods, especially cereal.

And one invention was crucial to our early success.

“The puffing gun is essential for our cereal group. It really changed everything that we did,” says Corporate Archivist Susan Wakefield. She explains, that before the puffing gun, General Mills only offered flaked cereal – Wheaties was introduced in 1924.

But in the 1930s, developers had a formula for the first-ever puffed corn cereal, Kix.

There was a problem, however.

General Mills needed a cost-effective way to produce the new cereal. Developers turned to Thomas James, an engineer in the Mechanical Experimental Department, for help.

He concocted our puffing gun and other special processing machinery.

An excerpt from Fortune magazine in the 1940s describes how the invention worked.


Going into the forty guns which look like heavy steel barrels, the cereals are damp and soggy. The barrels are clamped shut and revolved as the heat and pressure in them slowly rise. When the pressure has reached about 100 pounds, a workman flips the gun over, aims it at a wire screen and pulls a trigger. The gun goes boom! and a shower of Kix or Cheerioats hits the screen like hail.

Trix, Cocoa Puffs and Lucky Charms are just a few of the other General Mills cereals that depend on the puffing gun for their inflated, consistent shapes.

Wakefield explains more about the early history of the puffing gun in this video.

Our puffing gun has evolved somewhat over the years. The original invention produced cereal in batches.

In the 1960s, a continuous puffing gun was created to increase output and produce a more uniform shape. The C-gun, as it was called, used a gas flame. In the 1980s an electrically heated puffing gun, or E-gun, was introduced.

Phil Zeitlow began his career developing new cereal products and processes at General Mills in 1964. At that time, the C-gun was replacing the batch gun.

“This new gun produced a much more uniform product with less burned pieces … The product puffing rates through the C-Gun were originally 20-30 pounds per minute. Through many improvements the rates are now well over 100 pounds per minute,” says Phil.

Phil admits that he plugged and burned up guns too many times to count trying to puff new grains and products!

The puffing gun, despite being 75 years old, never fails to fascinate.

In fact, the Museum of Food and Drink (MOFAD) in New York City recently debuted a puffing gun exhibition, appropriately titled Boom!

Emma Boast, research coordinator for MOFAD, says the museum knew it wanted its first exhibit to be on breakfast cereal because Americans are so familiar with it.

“We sort of stumbled across this puffing gun not really realizing that it was so integral to the history of cereal and discovered there’s a company in Nebraska that actually still produces these machines based on designs from 1939.”

MOFAD hopes to bring the traveling exhibit to streets, parks, plazas and schools in New York and beyond.

Everyone who sees their puffing gun exhibit gets to sample the rice, corn or pasta that is blasted out – small puffs of cereal history.