What method can a winemaker use to stop fermentation intentionally?

The method a winemaker can use to intentionally stop fermentation is by killing or removing yeast. Fermentation is a biological process carried out by yeast where sugar is converted into alcohol and carbon dioxide. To halt this process, a winemaker can employ several techniques, with the most direct way being to eliminate the yeast that is responsible for fermentation.

This can be achieved through various means, such as heating the wine to a temperature that kills the yeast or adding sulfur dioxide, which is commonly used in winemaking as a preservative and yeast inhibitor. Additionally, filtration techniques can remove yeast from the wine, thus stopping fermentation. By eliminating the yeast, the winemaker effectively halts the conversion of sugars into alcohol, allowing them to retain the desired flavor profile and residual sweetness in the wine.

The other methods listed are not suitable for intentionally stopping fermentation. For instance, adding more sugar would further stimulate yeast activity, while increasing the temperature could enhance fermentation rather than stopping it. Similarly, adding more yeast would also promote the fermentation process, contradicting the goal of halting it. Thus, the action of killing or removing yeast is the most effective and appropriate method to stop fermentation in winemaking.