Buttermilk Scones

Our answer

Nigella's Buttermilk Scones (from Kitchen) use a combination of bicarbonate of soda (baking soda) and cream of tartar as raising agents. Cream of tartar is an acid and it reacts with the alkaline bicrbonate of soda to create carbon dioxide bubbles. These expand with the heat of the oven and cause the scones to rise.

Baking powder can be used as an alternative. Instead of the 2 teaspoons cream of tartar and 2 teaspoons bicarbonate of soda you could use 1 tablespoon (= 3 teaspoons) baking powder plus 1 teaspoon bicarbonate of soda. It should also be possible to replace the cream of tartar with another acid, such as lemon juice or a distilled vinegar. So you could try 2 teaspoons bicarbonate of soda and 2 teaspoons lemon juice. Always use proper measuring spoons when measuring raising agents and use level spoonfuls (unless the recipe states otherwise).

Whichever combination you use it best to bake or freeze the scone dough as quickly as possible as the raising agents will only last for a certain amount of time once the dough has been mixed.