Wine of this class is wine (other than grape wine, citrus wine, or fruit wine) made by the normal alcoholic fermentation of sound fermentable agricultural products, either fresh or dried, or of the restored or unrestored pure condensed must thereof, with the addition before or during fermentation of a volume of water not greater than the minimum necessary to correct natural moisture deficiencies in such products, with or without the addition, after fermentation, of pure condensed must, and with or without added alcohol or such other spirits as will not alter the character of the product, but without other addition or abstraction except as may occur in cellar treatment: Provided, That a domestic product may be ameliorated or sweetened in accordance with
part 24, of this chapter, and any product other than domestic may be ameliorated before, during, or after fermentation by adding, separately or in combination, dry sugar or such an amount of sugar and water solution as will not increase the volume of the resulting product more than 35 percent, but in no event shall any product so ameliorated have an alcoholic content, derived by fermentation of more than 14 percent by volume, or a natural acid content, if water has been added, of less than 5 parts per thousand, or a total solids content of more than 22 grams per 100 cubic centimeters.