Which ingredient is commonly added to cocktails for a fizzy texture?

Soda is commonly added to cocktails for a fizzy texture because it contains carbonated water, which provides carbonation and effervescence. The bubbles in soda contribute to a light and refreshing mouthfeel, enhancing the drinking experience. This characteristic makes soda a popular choice for mixed drinks, as it can balance stronger flavors and add a refreshing quality.

In contrast, water is generally used to dilute and mellow the strength of a drink, while juice adds flavor and sweetness rather than fizz. Cream contributes body and richness to cocktails, but it lacks any carbonation. Therefore, soda is the ideal ingredient to achieve that desired fizzy texture in cocktails.