Berries should be ripe and plump. Put into a large wood or stone vessel with a tap; pour on sufficient boiling water to cover them; when cool enough to bear your hand, bruise well until all the berries are broken; cover up, let stand until berries begin to rise to top, which will occur in three or four days. Then draw off the clear juice in another vessel, and add one pound of sugar to every ten quarts of the liquor, and stir thoroughly. Let stand six to ten days in first vessel with top; then draw off through a jelly-bag. Steep four ounces of isinglass in a pint of Wine for twelve hours; boil it over a slow fire till all dissolved, then place dissolved isinglass in a gallon of blackberry juice, give them a boil together and pour all into the vessel. Let stand a few days to ferment and settle; draw off and keep in a cool place. Other berry Wines may be made in the same manner.
The Whitehouse Cookbook, by Mrs. F.L. Gillette (Year 1887)