Bring the water to a boil. Grind the thyme lightly in a pestle and mortar. Pour the boiling water over the thyme and let it sit, covered, for at least 24 hours.

Mix all ingredients thoroughly. Let it ferment until it has at least doubled in volume.

Mix all flour with thyme-infused water and let the dough autolyze for 60 minutes.

Add salt and 70 grams of levain and incorporate it into the dough. Let the dough rest for 15 minutes.

Work up some dough strength with your preferred method, like stretch and fold or slap and fold. You can also knead the dough on a working surface. Continue until the dough starts to come together and becomes less sticky. It should take about 5-10 minutes.

Perform 3-4 stretch and folds during bulk fermentation. Perform the first 15 minutes after you have added salt and starter, and space out the rest with 15-30 minutes intervals. You may have to increase or decrease the amount of stretch and folds depending on how the dough behaves. If you feel a lot of resistance, it's time to stop. You can also check the dough with the windowpane test.

The total time for bulk fermentation should be about 4-6 hours, depending on temperature, the strength of starter, etc. When the dough has increased about 50-70% in volume and has a slightly domed bubbly surface it is ready. If the dough jiggles when shaking the bowl, it's also a good sign.

Dump out the dough on your working surface and shape it into a round with your bench knife. Let the dough rest for 15-30 minutes, giving it time to relax a bit. Shape the dough into your preferred shape.

Flour a banneton and sprinkle with wheat or rice flour. Place the loaf in the banneton and let it proof for 1- 1,5 hours at room temperature. You can also let it proof longer, 8-14 hours, in your refrigerator, depending on temperature. Make finger poke tests regularly to make sure the dough is not over-proofed.

Preheat the oven to 480ºF/250ºC. Score the loaf and bake it for 45-50 minutes. If you are using a dutch oven or a clay cooker, remove the lid after 15 minutes. You may have to reduce the heat in the last 15-20 minutes.

Let the loaf cool on wire racks.