As an expert sommelier and brewer, I can provide you with some insights on boiling hard apple cider. Generally, it is not recommended to boil cider because it can have negative effects on the final product.
When cider is boiled, it can cause the pectins in the liquid to set. Pectins are naturally occurring substances found in fruits, including apples, and they contribute to the texture and mouthfeel of the cider. Boiling the cider can cause these pectins to form a gel-like substance, resulting in a permanently hazy beverage.
To avoid this, it is best to simmer the cider instead of boiling it. Simmering refers to heating the cider gently over low to medium heat, just below the boiling point. This will help preserve the natural flavors and prevent the pectins from setting.
If you choose to simmer the cider, you can also consider adding additional ingredients like brown sugar or honey to enhance the sweetness and flavor. However, it's important to note that this is optional and depends on your personal preference. Adding brown sugar or honey can complement the natural apple flavors and provide a hint of sweetness to the cider.
In my personal experience, I have found that simmering the cider with a touch of brown sugar can create a delicious and well-balanced beverage. The gentle heat allows the flavors to meld together while still maintaining the clarity of the cider.
To summarize, boiling hard apple cider is not recommended as it can lead to a hazy beverage due to the setting of pectins. Instead, simmering the cider over low to medium heat is a better option to preserve the flavors and clarity. If desired, you can add brown sugar or honey during the simmering process to enhance the taste.