What is the name of the escala containing the most aged wine located on the floor of the system?

The term that refers to the level containing the most aged wine within the sherry aging system is "Solera." In the solera system, the oldest wine is held in the bottom tier, known as the solera, where it is continuously replenished with younger wines from the tiers above as bottles are filled. This allows for a gradual blending of different vintages and ensures that the wine produced is consistent in flavor and quality over time while retaining some characteristics of the older wines.

The other terms in the context of sherry production refer to different aspects of the aging process. For instance, "Criadera" refers to the tiers above the original solera level, where younger wines are aged before being blended with the older wines. "Rocio" is not commonly associated with the traditional terminology of the solera system, and "Saca" refers to the process of drawing wine from the solera and bottling it for sale. Understanding these terms helps in comprehending the complex nature of sherry wine production and the significance of the solera as the most aged component.