The patent number for the Artificial Freezer is US3254A. It was patented on September 9, 1843, and antedated on July 29, 1848. The Artificial Freezer contained a hand crank, which, when cranked, would spin and rotate two adjacent broad, flat slates containing an array of holes, which would assist in churning the ice cream, making the ice cream more uniform, while also making it easier to remove the ice crystals in the interior walls of the cylindrical container in which the spatulas were fit in.[8] These metal spatulas were attached to this pipe called the “dasher”, which was attached to the handle crank protruding out from the Artificial Freezer. Harnessing the principles of thermodynamics and endothermic reactions, Johnson’s Artificial Freezer was very effective in making ice cream. The wooden tub contained a mixture of salt and crushed ice, thus melting the crushed ice, but dropping the temperature of the solution below freezing point as a result of salt lowering the melting point of liquids. This, in conjunction with the ice cream solution, extracts heat energy from the ice cream, in turn freezing it. Johnson also was able to create the Artificial Freezer so that when using a border to split the machine down the middle, two different flavors of ice cream could be cranked and made at the same time.

In the "artificial freezer", which was the name of the original patent, it was possible to make either ice cream or sorbet, that would last about 30 minutes. There were no electric solutions to keep things cool, as the refrigerator had not been invented and not everybody had an icebox.

With these elements combined, it made it much easier, more efficient, and less labor-intensive for ice cream parlors to produce ice cream. Thus, a more efficient solution made it cheaper to produce ice cream, which in turn, made the ice cream cheaper. This granted accessibility to this dessert across all economic classes, which previously was too expensive for middle and lower classes as the production of the ice cream made it too expensive.

Johnson received US$1,500 during the course of her life for her patent. She made her final changes to her patent on September 9, 1843.[16] Despite Johnson's success and future impact she had with the Artificial Freezer, she sold the rights of the patent to William G. Young, a Baltimore native, who then improved on the ice cream freezer on May 30, 1848. Johnson sold the rights of the patent to Young for US$200. Some of the improvements included a similar internal spatula covered with holes, however, the mechanics of the handle were changed make the ice cream much cooler, also simultaneously speeded up the process of freezing.

Today, ice cream is one of the most popular desserts in the world. In 2019, about 6.4 billion pounds of ice cream and frozen yogurt were made in the U.S. Also, the ice cream industry has a major impact on the U.S. economy as it generates about 28,800 jobs and about $1.8 billion dollars in direct wages.

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