Lemon liqueur proof neutral spirits to extract from it the lemon oil (an essential oil). The extraction is then diluted with simple syrup. Different varieties of lemon are used to produce different flavors. The variety of lemon used is usually dictated by region. Various alcohols can be used to give distinct flavors. A higher proof alcohol maximizes extraction of the lemon flavor, whereas darker alcohols add complexity of flavor. Many commercial brands of lemon liqueur are produced in Italy, in several styles (see Italian liqueur). In Italy, especially in Campania, lemon liqueur is consumed as a chaser ("ammazzacaffè") to coffee. Lemon liqueur
Chocolate liqueur cacao"). An early 19th-century American cookbook, published in 1825 and preserved in an historical archive in South Carolina, includes a similar recipe. Throughout the 19th century and into the early 20th century, manuals and encyclopedias in French, English, and Spanish give similar recipes. A late 19th century food science manual gives a recipe that includes techniques for clarifying and coloring the liqueur. A similar early 20th century manual gives four recipes. There are several brands of chocolate liqueur on the market; this is attributed to a 1990s "chocolate craze". Early 19th century recipes for chocolate liqueur featured whole cocoa beans.