The color in these three classes of wine may be red or white, depending on whether or not the color is extracted from the skins in the process of fermentation. To make red wine, of course, the grapes to be fermented must have red coloring matter in skin or juice or both. Each of these groups of wine includes a very large number of kinds distinguished by the name of the region, the locality or the name of the vineyard in which a wine is made. Wines are still further distinguished according to the year of the vintage. _Wine-making._ There are four distinct stages in the making of wine after the grapes are grown. The first is the harvesting of the grapes when they have reached the proper stage of maturity, which is known as "wine-making ripeness." This stage of ripeness is determined by means of a must-scale or saccharometer. The wine-maker squeezes the juice from a number of bunches of grapes into a receptacle into which he drops the must-scale, whereupon the sugar-content of the juice is indicated on the scale, determining whether the proper stage of ripeness has been reached. Suitable varieties of grapes having been grown, it is necessary that they be permitted to hang on the vine until the proper degree of ripeness is developed, after which they are delivered at the winery as free as possible from injury or decay. The second stage is the preparation of the grapes for fermentation. The grapes are weighed on arriving at the winery and are then conveyed either by hand or more often by a mechanical conveyor to the hopper or crusher. The ancient method of crushing, which still prevails in some parts of Europe, was to tramp the grapes with bare feet or wooden shoes. Tramping has been superseded by mechanical crushers which break the skin but do not crush the seeds. The best mechanical crushers consist of two-grooved revolving cylinders. As the grapes pass through the crusher, they fall into the stemmer, a machine which tears off the stems, discharging them at one end, while the seeds, skins, pulp and juice pass through the bottom to the presses usually on the floor below. There are several types of wine-presses, all of which, however, are modifications of screw, hydraulic or knuckle-joint power. In large wineries, the hydraulic press has almost driven out the other two forms of power and when great quantities of grapes must be handled a number of hydraulic presses are usually in operation. The grape pomace is built up into a "cheese" by the use of cloths and racks variously arranged. The "cheese" is then put under heavy pressure from which the juice or "must" is quickly extracted.