How to make ice cream
A design from more than a century and a half ago, is the still alive and well in modern-day ice cream makers.
To make the ice cream, you will need some sort of ice cream maker. The one pictured to the right was patented by Nancy M. Johnson in 1843. This basic concept is still use today.
An inner metal cylinder that contains a rotating paddle, operated by hand or a motor, is placed in an outer bucket with room for crushed ice and rock salt to be added. The ice and water undergoes an endothermic reaction which creates a super cool surface on the inside of the metal cylinder helping to form a thin layer of ice cream. As this happens, the rotating paddle sweeps around and scrapes off the thin layer in order to let a new layer form.
A word of caution: Add the custard to the ice cream cylinder and start rotating the cylinder, either with a rotor or by hand, BEFORE adding crushed ice and rock salt to the external section of a ice cream machine. If you don’t start rotating the cylinder first, the mixture will start freezing on the inside of the container and soon the blade will not be able to move. For more details, follow the ice cream maker directions–remembering they were probably written by someone who has never made ice cream before.
Jeffersonian ice cream–Click the link for Thomas Jefferson’s wonderful ice cream recipe.