A milkshake is:

• in New England, a beverage which is made from milk and flavorings.
• in the rest of the United States, a beverage which is made from milk, ice cream, and possibly other flavorings. In much of New England, this is known as a frappe (pronounced to rhyme with "cap"), and in Rhode Island this beverage is known as a cabinet.
• in fast food restaurants, usually known only as a "shake", made from ice milk, flavorings and thickening ingredients, or other similar recipes.

An important factor that distinguishes a milk shake from simply being flavored milk is that it is usually prepared in some sort of blender rather than being simply stirred. There are machines which are specifically designed for the blending of milk shakes. Often, these machines mix ingredients and insert air into the milkshake mix, causing the consistency to smooth out and the shake to thicken up as the shake is blended. Some outlets use machines where milk and mix are frozen and mixed together inside a container within the machine - while others prepare and mix the shake "by hand" within a special stainless steel cup, often called a malt cup or mixing can.

The most common flavors of milkshake are vanilla, chocolate, and strawberry, though other ingredients such as bananas or Oreos may be used. A common additive is malt, which make a malted milkshake. Fast food restaurants and soda fountains often sell milkshakes. Some milkshake recipes call for ice cream in the flavor of the milkshake while others call for vanilla ice cream plus a flavor additive, such as a syrup or fruit. These different methodologies often result in a surprisingly large difference in taste and many people have a distinct preference for one method over the other. Recipes which rely heavily on fresh fruit and made without ice cream are called smoothies.

Milkshakes can be made from ordinary milk mixed with powder or concentrate although these drinks would simply be considered "flavored milks" in most places. Common brands include Nesquik and Crusha. Bottled milkshake is also common, commonly being sold in 330 mL, 500 mL or 1 liter bottles. Gulp! , Frijj , Yazoo and Mars are well known brands of bottled milkshake.

While there are many different drinks called "milkshakes" now, the original milkshake is reputed to have been invented in 1922 by a Walgreens employee, Ivar "Pop" Coulson in Chicago, who took an old-fashioned malted milk (milk, chocolate, and malt) and added two scoops of ice cream, creating a drink which became popular at a surprising rate, soon becoming a high-demand drink for young adults around the country. This lends credence to the premise that the ice cream version is the original, and pivotal, ingredient...as well as the reason for the "shake" component of the name.

See also

• Foodshake
• Hot chocolate
• Kelis - Known for singing the lyrics "My milkshake brings all the boys to the yard"