Mix the flours and first water together in a bowl (remember that water temperature is your main control point for being the master of your fermenting times). Mix until there are no wet or dry bits, scrape the bowl down and cover (see photos 1–5 on the following pages).Leave this for 2–4 hours. This wait is called ‘autolysis’; the purpose is to allow your flour to hydrate fully. The length of time here can be loose, so give it whatever works for your day.
Add your levain (weigh this out as it is slightly different for each recipe; any leftover can go in your discard tub) and second measure of water. Squish, squeeze and squelch your dough; it will go weird and slimy – don’t worry, this is normal. When it is all together, scrape the bowl down, cover and leave for 30 minutes. Now add your salt and mix this through: again, keeping everything in the bowl, wet your grabby hand and, using your fingers, squeeze the dough over and over again until the salt is totally incorporated, then mix more for good measure. You want to give this a good 8 minutes. Take your time; it feels nice and this is the only bit of ‘hard’ work you’ve got to do. Use your scraper to get under the dough and lightly oil the inside of the bowl.
Cover with a lid or a dish towel and leave somewhere warm for 1hour. Take a mental picture of how much the dough fills the bowl (or mark the bowl with a pen); by the very end you want it to have almost doubled in size. While this is only a rough indicator, it’s a good one to have in your back pocket when gauging if you are ready to shape. Now for the next 4 hours you are going to give the dough a ‘fold’ every hour. This just means grabbing the edge of the dough with a wet hand, stretching it up as high as it will go and folding it over itself, working around the bowl as many times as the dough will let you until it feels tight and as if it might tear. This means over the 4 hours you will have given the dough 3 folds. With each fold you should be starting to see more life in the dough. This whole process is what we call the bulk fermentation, and where the magic is happening.
After the last fold give it a final 30 (ish) minutes. You should have ashiny, coherent, strong dough that wobbles when you carefully prodit. If it feels wet and sticky, give it another fold and leave it for afurther 30 minutes. If it feels strong, just not that lively, leave out theextra fold but still give it more time. This is the fermentation periodand you can’t really rush it; it doesn’t take much of your attention, sojust let it do its thing. You’ll get a feel for this sweet spot the moreyou bake.