1. In a clean jar or a bowl, plastic or glass, mix 28g flour with 56g pineapple juice. Cover with a lid or cling film and keep in a warm place for 48 hours. Bubbles should appear after a day or two but don’t worry if nothing happens – it will become active after first feeding.
2. After 48 hours mix in another 29g of flour the remaining 29g of pineapple juice. Leave in a warm place for 1 – 3 days but keep watch: when it becomes foamy, mix in 56g flour and 29g water. Re-cover and leave for another 1 – 2 days on a kitchen worktop, stirring twice a day with a wet spoon. It should now rise to twice the volume and again, it might happen sooner than 2 days.
3. Now convert this seed culture into starter, or production dough: in a large bowl mix 340g flour and 255g of water. Add 115g of the initial starter, or seed culture and discard the rest. Mix well with a dough mixer of by hand, then turn it out onto a lightly floured surface and knead for a couple of minutes – it should be springy, elastic and look and feel like bread dough. Place it back in the large bowl, cover and keep in room temperature for 4 – 8 hours, until doubled in bulk. It is now ready to use for making bread, and will keep fresh in the fridge for up to 5 days. After that time it needs feeding: discard half of it and mix with more flour and water in 4:3 proportions.
4. For the no-knead bread, mix the sourdough starter with the lukewarm water until almost dissolved – if the starter had been in the fridge, use warmer water, at about 40C/104F. Mix the flour with salt and pour in the watered down starter. Mix everything until combined and the flour is hydrated, but no kneading! Cover the bowl with cling film and a clean tea towel and leave in room temperature for 12 – 24 hours (depending on temperature in your house. 18 hours at 20C worked for me). The dough will have puffed up a lot and then subside, showing dimples and bubbles on the surface.
5. Turn it out onto a clean work surface dusted with flour. Fold the edges of the dough towards the middle, forming a round loaf. You can now place it in a well-floured banneton or a proving basket, or just on a floured tea towel or piece of parchment on a worktop – seam side down. Leave it to double in size, for up to 2 hours.
6. Preheat the oven to 250C/450F/gas 8 and place a cast iron casserole, a Dutch oven or a clay cloche with a lid on the middle rack about an hour later.
7. When you’re ready to go, drop the loaf into the preheated dish (best to take it out of the oven for this). If you invert the loaf into the dish, there’s no need to slash it; if you lower it in on the parchment, give it a few slashes with a very sharp knife or a baker’s lame.
8. Sprinkle with the sesame and/or poppy seeds, put the lid on and bake for 20 minutes. Take the lid off and bake for another 20-25 minutes until deep golden on top, turning the dish round if necessary, to brown the loaf evenly. Cool on a wire rack. It will be incredibly crusty so take care slicing while still warm!