Preheat your oven to 180 degrees Celsius.
Gather together your bottle of beer, 350 g self-raising flour and 4 tbsp caster sugar.
Sift the flour into a large bowl, then stir in the sugar. Pour in the beer. It will fizz up!
Stir with a wooden spoon until well mixed, it will bubble as you do this. It will be a runny sticky mixture.
If adding any extras like herbs, spices, cheese etc, stir them in now.
Lightly oil a large loaf tin (2 lb / 1 kg).
Pour the bread batter into the oiled tin. Sprinkle over a little cayenne pepper to add colour (optional).
Bake for 45-50 minutes until golden brown and cooked through. It may rise into odd shapes from the action of the beer.
To check the bread is cooked through you can test with a cake tester/skewer (make sure it comes out clean and dry) or use a food thermometer to check the internal temperature has reached around 90 degrees Celsius.
Remove from the oven, leave in the tin for 5 minutes approx to cool slightly, then remove from the tin and place on a cooling rack. Slice when cooled completely.