1 tbsp brown sugar
½ a 500mg vitamin C tablet, crushed to a powder
450g spelt flour (about 3.5 cups)
1 tsp fine sea salt
50g unsalted butter, melted (about 4 tbsp)
Bring 300ml dark ale or porter to the boil in a saucepan (don't let it boil over) and simmer for a minute or so to drive off the alcohol, which could slow down or even stop the yeast. Pour the ale into a jug, leave until warm, then top up to 300ml with warm water.
Scald a mixing bowl with boiling water, wipe it dry, then add the warm ale, yeast and sugar. Stir well, then add the vitamin C, flour and salt, and stir well again. Pour in the melted butter and squidge the lot together to work the fat through the dough. Cover the bowl with a cloth and leave for 10 minutes.
Give the dough three light kneads over 30 minutes, then cover and leave for 15 minutes.
Lightly flour the work surface, roll the dough into a rectangle, roll up tightly and place seam-side down in a buttered and floured 2lb loaf tin. Cover the tin with a tea towel and leave in a warm place until the dough has doubled in height (about 1-1½ hours).
Heat the oven to at least 220C/430F (200C/390F fan-assisted), though if you can get it to 240C/460F (220C/430F fan-assisted), even better.
Dust flour over the dough with a tea strainer, cut the loaf down the middle with a serrated knife, and bake for 20 minutes. Reduce the heat to 200C/390F (180C/350 fan-assisted) and bake for a further 20-25 minutes until dark golden brown, remove from the oven and tin, and cool on a wire rack.