Apple butter is essentially a thicker and spicier version of applesauce, traditionally made by slow-cooking sliced or pureed apples in copper kettles for up to 12 hours or more. The apples are constantly stirred with long paddles. The heat causes the fruit's natural sugars to caramelize, thus giving apple butter its distinctive deep brown color.

Apple butter is also known for its spicy flavor, which comes from the addition of traditional apple pie spices such as nutmeg, cloves and especially cinnamon. Commercially produced apple butter is generally available in grocery stores, but the traditional homemade apple butter is usually canned in jars for personal consumption or sold at local farmers' markets, craft shows and festivals.

Apple butter does not contain any dairy products, but derives its name from the buttery texture of the finished apple preserves. In fact, some people use apple butter as a condiment or spread for sandwiches, in the same way others might use mayonnaise or mustard. Apple butter is said to be especially good on ham or pork sandwiches, since many traditional Pennsylvania Dutch or German recipes combine apples and pork-based meats. Even if apple butter is not used specifically as a sandwich spread, it is also popular as a topping for pancakes, biscuits and buttered toast.

The tradition of apple butter is thought to have been brought to the United States by Germans who settled in Pennsylvania. The so-called "Pennsylvania Dutch", a corruption of Deutsch, or German, were very pragmatic by nature, and realized they needed a way to preserve their food during the winter months. Since apples were in abundance during the fall season, they first began preserving the fruit as apple jam or applesauce. The canned applesauce did not have the shelf life they had hoped for, however, so a slow-cooking process was developed. The extra cooking time turned the applesauce into a more stable "apple butter," and the added spices also aided in the preservation process.

Duplicating the traditional apple butter making process in modern times has proven to be a challenge, however. Some historical societies and other traditionalists still hold apple butter making sessions, using volunteers to stir the pots in shifts and also maintain the fires which provide the heat. Decent apple butter can also be made in an electric slow cooker at home, as well. Applesauce blended to a very fine consistency can be placed in a slow cooker along with the traditional cinnamon, nutmeg, allspice and cloves. This mixture should be allowed to reduce for at least 12 hours, with a slight gap in the lid to allow steam to escape. Specific recipes for converting applesauce into apple butter are available in a number of cookbooks and cooking websites.