Cider shell refers to the outer or protective layer formed on the surface of fermented apple juice, commonly known as cider. This layer is characterized by its filmy or gelatinous appearance, forming a thin skin or film on top of the liquid. It is a natural byproduct of the fermentation process in which apple juice is transformed into cider, typically through the action of yeast.
The formation of a cider shell is a result of the interaction between the yeast and the sugars present in the apple juice. As the yeast consumes the sugars, it produces carbon dioxide gas and alcohol. During this process, a layer of proteins, pectin, and other compounds float to the surface, forming the cider shell.
The thickness and consistency of the cider shell can vary depending on factors such as the type of apples used, fermentation conditions, and the presence of certain enzymes. Some ciders may have a thin and delicate shell, while others may have a thicker and more robust film.
Cider makers often refer to the cider shell as a sign of fermentation activity. It is generally recommended to gently stir or mix the cider to break up the shell before consuming or further processing the liquid.
In addition to its visual characteristics, the cider shell can sometimes have a slight tart or tangy flavor due to the compounds present in it. However, it is typically strained or removed before bottling to achieve a clear and smooth final product.
