Why Do My Banana Muffins Taste Odd?

Our answer

Nigella's Chocolate Banana Muffins (from KITCHEN) are rich and moist muffins that are a perfect way to use up bananas that have become over ripe. Bicarbonate of soda (baking soda) is the raising agent and this can sometimes taste bitter or soapy if the wrong quantity is used. Make sure that you measure the bicarbonate of soda with a proper 1 teaspoon/5ml measuring spoon and the spoon measurement should be level. Also make sure that there are not any lumps in the bicarbonate of soda, so that you don't get pockets of bicarbonate of soda in the muffins. If it does have lumps then sift the flour, cocoa and bicarbonate of soda together before adding the dry ingredients to the mixing bowl.

Bicarbonate of soda needs an acid ingredient to react with to make it work and acid can also temper the bitterness. Bananas are usually slightly acidic, though the acidity drops as they ripen, and there is a very small chance that if the bananas were really, really ripe (ie completely black and shrivelled) then this could affect the way the bicarbonate of soda acts, though in this case the muffins would also not have risen much. If you used natural cocoa powder then this is also acidic, but if it was Dutch processed cocoa powder then that has a more neutral pH, and could have affected the muffins very slightly. However, we suspect that too much bicarbonate of soda or lumps in the bicarbonate of soda are a more likely reason for an odd taste.