Now the ice cream needs to be reduced to a very low temperature, zero degrees Fahrenheit or below. Factories make it even colder since they need the ice cream to stay frozen while it is packaged and loaded onto trucks. It needs to be very cold to freeze the ice cream quickly and prevent the formation of large ice crystals. This process is known as hardening. "Soft-serve" is often simply ice cream that has not gone through this process.

　　We'll learn about the ice cream industry in the next section.

　　Ice Cream Industry

　　In 1999, retail sales of ice cream in the U.S., the worldwide leader in ice cream production, topped $4 billion. In 2002, more that $20 billion was spent on frozen desserts. The leading states in ice cream consumption are California, Indiana, Pennsylvania, Texas and New York . Americans ate an average of 21.5 quarts of ice cream per person in 2004.

　　With that much money to be made, the ice cream industry can be secretive and underhanded(秘密的). Deborah Hanny, owner of Sweet Jenny's Ice cream in Williamsville, NY, protects her recipes carefully. Her shop has been photographed by men in suits and she once caught someone in he upstairs office hurriedly trying to copy down her recipes.

　　Ice cream making secrets are seldom passed down from generation to generation these days. So where do people in the ice cream industry learn their craft? At ice cream school. Pennsylvania State University offers a week-long "Ice Cream Short Course" intended for industry professionals. The course teaches the science and technology used to make ice cream. The also offer Ice Cream 101 for ice cream hobbyists who just want to learn more about their favorite frozen treat. The University of Guelph, Ontario's Dairy Science and Technology school, also has a long history of teaching ice cream science.

　　1. Eight percent of all the milk produced in the U.S. ends up in a frozen dairy product.

　　2. Any frozen treat can be called ice cream.

　　3. In addition to milk fat, non-fat milk solids, sugar, and air, ice cream also contains stabilizers and emulsifiers.

　　4. The process of making ice cream at home is different from that in a factory.

　　5. Once the ice cream has come out of the ice cream maker, the process is finished.

　　6. Ice cream making secrets are passed down from generation to generation these days.

　　7. Many universities in U.S.A. offer courses of ice cream science.

　　8. The range of milk fat used in ice cream can go ________.

　　9. In 1999, retail sales of ice cream in the U.S. topped ________.

　　10. With that much money to be made, the ice cream industry can be ________.