Using unsalted butter to make ghee is recommended because the salt in salted butter can burn and affect the flavor and purity of the ghee. Unsalted butter allows for better control over the final taste and ensures a cleaner, more authentic ghee.
When making ghee, butter is slowly simmered to remove water and milk solids, leaving behind pure butterfat. Salt, present in salted butter, doesn't evaporate during this process. Instead, it can concentrate and potentially burn at the high temperatures required for ghee making. This burning can impart a bitter or off-flavor to the ghee, diminishing its quality and intended taste. Furthermore, the salt can interfere with the separation of milk solids, making the process less efficient and potentially leaving impurities in the final product. Using unsalted butter ensures a cleaner separation, a purer flavor, and a higher quality ghee overall. The absence of salt allows the natural nutty and rich flavors of the butterfat to shine through, resulting in a more authentic and versatile cooking ingredient.
Always use high-quality unsalted butter from grass-fed cows if possible. The quality of the butter directly impacts the flavor and nutritional value of the ghee.