Which of the following is not part of the solera system's operation?

The solera system is a traditional method used in the production of sherry wine that involves the mixing of different ages of wine to ensure consistency and quality in the final product. The correct choice here is the fermentation process, which is not a part of the solera operation.

In the solera system, the terms "saca" and "correr escalas" refer to integral components of its functionality. "Saca" is the process of drawing wine from the solera cask for bottling, while "correr escalas" refers to the movement of wine between different criaderas (or tiers) in the system. These components are essential for maintaining the age balance and characteristics of the wine.

On the other hand, fermentation is the initial process that occurs before the wine enters the solera system. It is the step where the grape juice converts into alcohol, laying the foundation for all wine styles, including sherry. Therefore, while fermentation is crucial in the overall winemaking process, it does not occur within the operation of the solera system itself.