unsalted butter

why do some recipes call for unsalted butter and sometimes add salt why not just use salted butter that most people have.

In a recipe calling for unsalted butter but the addition of salt, the salt is used as an agent while the unsalted butter is used as an ingredient.

For instance, if baking muffins, the muffins benefit from the salt (chemically speaking).

How it reacts with other ingredients will give you the results you need - crunchy, chewy, fluffy, etc.

When you use a salted butter you are using less butter because of dehyration and the salting process.

Many feel that unsalted butter in recipes always gives a better flavor and texture.

Many also feel there is no difference - depends on what you are making.

I hope this helps.