Final answer:
The Airen and Palomino grapes used for Spanish brandies are high in alcohol and low in acidity, which contrasts the characteristics of grapes used for French brandies like Cognac and Armagnac.
Step-by-step explanation:
The grapes used for Spanish brandies, such as the Airen and Palomino varieties, differ from the grapes used in Cognac and Armagnac.
Specifically, the grapes used for Spanish brandies are high in alcohol and low in acidity. This is due to the hot climate in the regions where these grapes are grown, which results in grapes with higher sugar content that, when fermented, produce a higher alcohol content.
The lower acidity is also a characteristic of these grapes, making this the defining difference from the grapes used in French brandies, which tend to be higher in acidity.