Some people think freeze-drying is a new way to keep food, but it isn’t. It actually dates back to ancient times when the Incas did it in the cold night air of the Andes Mountains. Today, a machine is used to remove all the water from the food, leaving its shape, color, and other features unchanged. In addition to making it possible to keep food longer, freeze-drying makes food weigh less. Less weight makes the food easier to carry, which is important in many situations, like camping or on trips into space. Freeze-drying is still done today because, over time, it has proven to be a very good thing to do.
What is the author’s purpose for writing the passage?
A.
to persuade readers against freeze-drying to preserve food
B.
to explain the history and process for freeze-drying food
C.
to entertain readers with a story about freeze-drying food long ago
D.
to compare freeze-drying to other ways of preserving food