Scatter polenta over the baking sheet.
Place the water in the small saucepan and heat until tepid.
Transfer to the measuring jug, add the yeast and honey and whisk to thoroughly mix.
Leave to stand for 10 minutes to activate the yeast.
Place the flours and salt in the mixing bowl and make a well in the centre.
Add the yeast mixture and the dark ale and bring together with your hands to make a sticky dough.
Turn out onto a floured work surface and knead for 10 minutes until the dough is smooth. Rye dough is somewhat tricky as it's very dense but persevere - even if it doesn't feel like other doughs it's important to stretch the gluten.
Clean the mixing bowl and lightly oil it.
Form the dough into a ball, place into the bowl, cover in clingfilm and put in a warm place for 2 hours.
Tip out onto a work surface and knock back.
Preheat the oven to 180C/350F/gas 5.
Shape the dough into an oval and place on the baking sheet.
Cover with the clean tea cloth and leave to rise for an hour. The surface of the dough may crack a little but that's fine.
Bake for 40 minutes checking after half an hour to ensure the top isn’t burning. If it is, place a piece of kitchen foil over the top.
Check that the loaf is cooked by tapping the bottom – it should sound hollow. If it doesn’t, take out of the tin and place upside down in the oven for 5-10 minutes.
Leave to cool on a wire rack for at least 20 minutes before serving.
