Sparkling Grape Wine

From 1922:

Take the grapes before they are fully ripe, put stalks and fruit in a convenient sized tub, delicately clean, bruise them until every berry is broken, and to every pound of fruit add a quart of cold water. Leave them for 3 days, stirring them twice or three times a day. Strain and add three and a quarter pounds of loaf sugar to every gallon of liquid. When this is dissolved put the wine at once into a cask, which should be kept full to the bung. It is best to reserve half a gallon for the purpose of filling it up as the fermentation subsides. In ten days add 1 pint of brandy and a quarter ounce of isinglass to every five gallons of wine. Keep the cask in a cool place. The wine should be bottled when the vines are in bloom the following summer, and the corks must be wired down.