The term "fortified" is used in connection with a wine not fermented exclusively from grape juice but from grape juice to which sugar has been added. This addition of sugar produces a larger quantity of alcohol than naturally would be found in the fermented juice. Wines fortified in this way are very commonly made in all countries where the climatic conditions are such as to produce grapes rather poor in sugar. Even in countries where ordinarily the grape contains a sufficient quantity of sugar to make a good wine there are occasionally wet seasons and cold seasons, or lack of sunshine, in which the grapes have a low content of sugar, and usually a corresponding high content of acidity. When the sugar content of the grapes is less than 14 percent it is quite the custom in many countries, including the United States, to add sufficient sugar to produce a wine of an alcoholic content of from 9 to 12 percent. In these cases it is seen that part of the alcohol in the wine is derived from sugar and the beverage is not much more of a wine than it is an undistilled rum.

A more common method of fortifying wine is to add the alcohol directly to the wine after fermentation. Presumably the alcohol which is added is brandy, but this presumption is not always verified by the actual facts of the case. Very frequently neutral spirits made from other sources, as for instance, Indian corn, the potato, or beet root and molasses, are employed for fortification. In the United States the spirit which is used for the fortification of wine is required by law to be distilled from grapes or the residues of the winery. This admits to fermentation pomace from which the grape juice is expressed, and in this way produces a variety of brandy which to most persons is wholly unpalatable. A brandy of this kind has an excessively high content of higher alcohols and ethers, and has a taste and flavor which are quite unpalatable to those not accustomed to its consumption.

Brandy which is used for the fortification of wines in the United States is usually freshly distilled in a rectifying column, and does not have the properties of a real brandy, due to the distillation of sound wines and proper ageing in wood.