Salted or unsalted butter — does it actually matter?

This is one of the most repeated rules in baking and it is mostly true for a reason people rarely give: the salt content of salted butter is not standardised. British salted butters range roughly from 1 to 2 per cent salt, so 250g of one brand can carry twice the salt of another. In a recipe with a lot of butter that is a real difference.

Step by step

1. Use unsalted where you control seasoning by measurement.Cakes, biscuits, pastry, buttercream, custards, enriched doughs. You cannot taste and correct these before baking, so an unknown salt load is genuinely awkward. Recipes are written on the assumption of unsalted for exactly this reason.
2. Use salted where you taste as you go.Sauces, sautéing, scrambled eggs, finishing a steak, on vegetables. You are going to season it anyway and you can adjust. There is nothing wrong with cooking in salted butter — it just moves the seasoning decision earlier.
3. Use salted where it is the point.On bread, on a jacket potato, on corn on the cob, in a salted caramel. The salt is the flavour, and unsalted butter with salt sprinkled on top is not the same thing because the salt is not dispersed.
4. Convert by subtracting salt.Roughly a quarter teaspoon of fine salt per 100g of butter is a reasonable average for British salted butter. If a recipe calls for unsalted butter plus salt, and you only have salted, reduce the added salt by about that much.
5. Ignore the freshness argument.Salt is a preservative, and the traditional advice is that unsalted butter is fresher because it cannot hide age. With modern refrigeration and turnover this is largely obsolete in a supermarket. Buy on date and store properly instead.
6. Check the fat content while you are looking.Butter must be at least 80 per cent fat in the UK; some European-style butters are 82 per cent or higher. That extra fat and lower water content makes a noticeable difference in pastry and laminated doughs, more than the salt question does.

Tips

• If you only want to keep one, keep unsalted and add salt. It is the one that can become the other; salted butter cannot be unsalted.
• For pastry and croissants, a higher-fat European-style butter with less water gives better lamination and a shorter, crisper result.
• Spreadable butter blends contain vegetable oil and behave differently in baking — more water, softer at temperature, and they can make biscuits spread. They are for spreading, as the name says.
• Salted butter browns very slightly differently because of the salt crystals, but the difference is not worth planning around.
• In savoury baking — cheese scones, savoury shortcrust — salted butter is perfectly sensible and saves adding salt separately.

Common mistakes

• Assuming all salted butter is equally salted — It varies roughly twofold between brands, and the amount is not always on the front of the pack. This variability, not the salt itself, is the actual reason baking recipes specify unsalted.
• Using a spreadable blend in shortcrust pastry — The added oil and water content changes how the fat coats the flour, and the pastry comes out tough or greasy. Use block butter, cold.

Questions people ask