Grapes, yeast, and fruit acids. There are only two basic ingredients in wine, namely grapes and yeast. The grapes are the main ingredient, while the yeast is necessary for fermentation and is used to convert the grape juice into alcohol and carbon dioxide. There can also be auxiliary ingredients, which are components used to increase the flavor of wine, enhance its aging ability, control the alcohol content, and prevent the wine from deteriorating, among other effects. Commonly used auxiliary ingredients are: fruit acid, tartaric acid, citric acid, copper sulfate and so on. Therefore, it is better for the wine's ingredient list to be grapes, yeast, and fruit acids. Because such ingredients are very clean and no other additives, the taste and flavor will be more pure.