Pre-heat the oven.
Rub some oil around the inside of a 1kg/2lb loaf tin or insert a baking liner.
Put the flour, bicarbonate of soda, Vitamin C, if used, and salt into a bowl, stir to combine and sieve into a mixing bowl.
Measure the boiling water into a jug and add the cold water and lemon juice, if used.
Add the yoghurt and stir to combine.
Pour this into the mixing bowl and stir everything together to make a soft, sticky dough mass.
Sprinkle the oil over the dough mass and using a spatula turn the mixture a couple of times in the bowl.
Tip the dough into the prepared tin and smooth the top.
Brush some oil over a piece of aluminium foil. With the oiled side down, cover the tin creating a dome so the bread can rise during cooking.
Bake for 55 minutes, carefully remove the aluminium foil and bake for a further 10 minutes.
Turn the loaf out of the tin, tap the base and if it sounds hollow the bread is cooked.
Leave to cool on a wire rack. Cool completely before slicing.
