In a large mixing bowl, pour in the cool water and sprinkle the active dry yeast on top. Let it sit for about 5 minutes until foamy.

Add the pumpkin puree and whisk until the mixture is smooth and well combined.

Gradually add the bread flour and fine sea salt to the yeast mixture. Stir until fully incorporated.

Cover the bowl tightly with plastic wrap and let it rise at room temperature for 1 hour.

Wet your hands and gently fold the dough in the bowl three to four times to tighten it slightly.

Cover it again and let it rise for an additional 3 to 4 hours.

Transfer the dough to the refrigerator for about 12 hours or overnight.

On a lightly floured surface, gently scrape the cold dough out of the bowl and shape it into a tight ball.

Let the dough rest on the counter for another 3 to 4 hours until it has risen again.

Preheat your 4-6 quart Dutch oven to 450°F (230°C).

Remove the Dutch oven and place the dough inside. Score the top of the bread with a sharp knife.

Cover with the lid and bake for 20 minutes, then remove the lid and bake for an additional 20-25 minutes.

Allow the bread to cool on a wire rack for at least 1 hour before slicing.