He started with some of the blandest foods he could find, corn meal and oatmeal. He made that into a dough and then added nuts. He then baked the dough into biscuits which he then crumpled into small pieces that he called granula. The name was already taken by another product so he changed it to granola.
Dr. John Kellogg worked with his brother to find more foods that he could use as part of a pure diet. They worked with different kinds of bread and even rolled a whole-grain dough into very thin sheets of toasted crackers. It was during the process for making their toasted crackers that they had cooked some wheat to put through the rollers. They were called away and did not get back to the cooked wheat until it had cooled. They ran this cooled wheat through the rollers and found that each individual grain became flattened into a very thin flake. The bland, crisp flake was heralded by the brothers as a wonderful new health food. In 1898, they repeated the process with corn and found that it worked the same way and created “corn flakes.”
Dr. John Kellogg loved the new bland food and began serving it immediately to patients at his facility. His brother Will Keith Kellogg had a different idea for the flakes. He believed that by adding sugar the flakes would eliminate the cardboard taste and would then make an excellent breakfast cereal. Dr. John Kellogg was horrified at the idea and refused. The pair argued but eventually they patented their flake cereals (wheat and corn) and created the Sanitas Food Company. The original plan was for the cereal to be mail order with the majority of the customers being former patients at the sanitarium. Wheat flakes proved to be very unpopular and were dropped but even corn flake sales remained low. Will Keith Kellogg continued arguing for the addition of sugar but Dr. John Kellogg adamantly refused.
In 1906, Will Keith Kellogg purchased the rights to make “corn flakes” and changed the recipe to include sugar. He then created the Battle Creek Toasted Corn Flake Company. He wanted to use the Kellogg name for his company but his brother refused and the pair fought over the issue. Will Keith Kellogg won out in the end and the Battle Creek Toasted Corn Flake Company became the Kellogg Cereal Company. In 1915, Bran Flakes were added and Rice Krispies in 1927. By 1930 they were the largest breakfast cereal maker in the world. The closest competitor to Kellogg was the Post Cereal Company which was founded by CW Post who had once been a patient at the sanitarium. Will Keith Kellogg always believed that CW Post had stolen the corn flakes recipe out of the safe at the sanitarium.