Cocoa Powder in Olive Oil Chocolate Cake

Our answer

There are two types of cocoa powder, natural and Dutch processed. Natural cocoa powder is the powder of untreated cocoa beans and tends to be slightly acidic. Dutch processed cocoa powder is manufatured using an alkaline (postassium carbonate)in the process and so is less acidic. Natural cocoa powder is lighter and redder in colour than Dutch processed and has a slightly sharper, more floral flavour, whereas Dutch processed cocoa powder is dark brown and has a richer, more rounded flavour. However the flavour is also determined by the quality of the beans used and a cheaper cocoa powder may not have the same taste as a better quality cocoa powder, regardless of whether it is natural or Dutch processed.

Generally in the US people advise to use natural cocoa powder if baking soda (bicarbonate of soda) is the only leavening in a recipe as the acidity of the natural cocoa powder will react well with the alkaline baking soda, giving a better rise. However in the UK there isn't the same differentiation (though you can look at the ingredients list to find out if the cocoa powder is Dutch processed). Consequently Nigella's Chocolate Olive Oil Cake (from Nigellissima and on the Nigella website) doesn't specify a type and works with both forms of cocoa powder but we would always suggest using a good quality cocoa powder. This cake is also usually made with ground almonds (almond meal) and is gluten free so will not rise as much as a regular cake and will be closer in texture.