1 tbsp lemon juice / cider / distilled white vinegar
Preheat the oven to 190 degrees Celcius. Line muffin moulds with paper liner / spray with non stick cooking grease / brush with melted butter.
Sift the dry ingredients; flour, baking powder and soda into a large bowl. Stir in salt and sugar and make a well in the centre.
In a separate bowl, combine all the wet ingredients; eggs, buttermilk, oil and vanilla extract and mix well.
Pour the combined wet ingredients into the well and fold until the batter is just mixed; the batter should look quite lumpy.
(Avoid over-mixing the batter as this will cause the muffins to be tough and chewy in terms of texture).
Gently fold in the blueberries and if you are using the frozen ones, do not defrost the berries, ensure they are still frozen and minimize the mixing as to prevent the berries to bleed into the batter.
Spoon the batter into the prepared moulds 3/4 full and bake for 20 - 25 minutes in preheated oven or until golden brown.
Cool on a wire rack before unmoulding the muffins and garnish as desired.
Combine both and allow to stand for 10 minutes before use.