Bicarbonate of soda has a limited shelf life so check the sell-by date when using it; otherwise your cakes might literally be a flop! You can make your own baking powder by combining 15ml/1tbsp ...

Proper storage is key to prolonging your baking powder’s shelf life. Keep it sealed in an airtight container in a dry place at room temperature. Don’t be tempted to keep it in the fridge.