Ice cream, which can be traced back to sixteenth century France, enjoys greater popularity in America than in other countries of the world. At its simplest, ice cream includes cream, milk, sweeteners and flavorings. Sometimes pasteurized eggs and small pieces of food, such as nuts, fruit or chocolate bits, are added. The majority of ice cream eaten in America is commercially produced, although homemade ice cream is easy to make with just a few ingredients and an ice cream maker.

Commercial ice creams usually include emulsifiers and stabilizers to prevent the formation of large ice crystals, ensure smooth texture, extend shelf life and control melting. Flavorings (both natural and artificial) are also added. Air is pumped into the ice cream during the freezing process to soften it. The industry term for the amount of air incorporated in ice cream is "overrun," which is given as a percentage. The less overrun the harder the ice cream and the more a given amount will weigh.

Ice cream is categorized as premium, regular, low-fat and nonfat. Premium products are more expensive than regular ice cream. They have higher levels of butterfat (sometimes as much as 20 percent) and generally less overrun. Regular ice cream has less butterfat and more overrun than premium ice cream. Low-fat ice cream must contain 3 grams of fat or less per serving. Nonfat ice cream has less than one-half gram of fat per serving.

Store commercial ice cream in airtight containers at 0°F for up to two months. Ice cream in opened containers will develop large ice crystals. Covering the surface of the ice cream will delay this process and help prevent the ice cream from absorbing odors from the freezer.

Homemade ice cream when properly made is smooth and creamy with fine ice crystals. For best results, carefully read the manufacturer's directions for the ice cream maker. Homemade ice cream develops large ice crystals after two or three days, resulting in a coarse texture, so try to eat it within a day or two of making it. The following tips will help produce smooth, creamy homemade ice cream:

• Thoroughly chill the ice cream mixture before freezing it to ensure a smooth texture. Chilling also cuts freezing time.
• Do not use egg yolks in ice cream unless they have been heated to 160°F. The heating destroys harmful bacteria.
• Fill the canister no more than two-thirds full to allow the mixture to expand.
• Layer the crushed ice and rock salt around the canister, replenishing as needed. Use 6 cups ice to 1 cup salt.
• The ice cream mixture must be constantly stirred during the freezing process.
• After freezing, the ice cream needs to stand for at least four hours to develop flavor. This can be done in the ice cream maker by packing it with additional ice and salt (4 cups ice to 1 cup salt--the higher proportion of salt lowers the temperature of the ice cream). The alternative method is to transfer the ice cream to a covered freezer container and place it in a 0°F freezer.