Liquors and liqueurs are "kissing cousins" with the same core ingredient: alcohol. The terms are not interchangeable because each has its own distinct characteristics. Although they can have the same range of alcohol content, liqueurs are much sweeter and are sometimes thickened with cream.
Basic liquors, including whiskey, vodka, rum, bourbon and brandy are made from various types of grains and plants. In turn, these liquors are used in creating the sweetened drinks known as liqueurs. Brandy is used more often than others. Although sugar is involved in the process of creating the original liquor, it dissipates after the fermentation process. On the other hand, liqueurs are specifically created by adding back in various sugars, as well as oils, herbs, nuts, fruits, flowers, chocolates or flavors. Alcohol content is usually lower for liqueurs, but not always. Liqueurs have an average range of about 15 percent to 30 percent alcohol by volume, but some reach as high as 60 percent alcohol by volume.
Confusion often occurs when basic liquor manufacturers release a flavored version of a classic alcoholic drink, often called infused liquors. Examples of this are spiced rum, honey tequila and fruit-flavored vodkas. Though these offshoots can be sweeter than their original versions, they are still far from the sweet and thick characteristics of a typical liqueur.