This bread was a successful experiment making a mini boule out of a mixture of 75% King Arthur Flour’s Keto wheat baking flour and 25% whole wheat flour. So, there were two experiments at the same time. First, making a small boule, because sometimes a normal sized boule is too much for the two of us. Second, making a boule which would be very low carb and low glycemic, but still would be tasty. I pieced together some guidance from Flourish (which used to sell to retail customers a high fiber flour) and from thepracticalkitchen.com on small batch baking, with my usual process for baking a boule.
This loaf was made with 250 g. of flour, about half my usual boule. I was surprised how fine and regular the crumb was even though it had 83% hydration. (High fiber flour is thirsty!) It took a total of three days. I have a set of very small measuring spoons for cheesemaking, so it was not hard for me to measure out 1/16 tsp. of yeast. The small amount of yeast and a long period of rising led to a light and flavorful loaf.
For the Poolish
60 g. whole wheat flour
1/16 tsp. yeast
80 g. water
For the Dough
180 g. King Arthur Keto wheat baking flour
120 g. water
5 g. salt
The afternoon of the first day, mix together the poolish ingredients in a smallish container. Cover and allow to ferment on the kitchen counter overnight.
On day 2 in the morning, the poolish should be light and fluffy. Mix it with the water, and then with the flour in a medium bowl using a dough whisk. When the ingredients are roughly combined, sprinkle the top with the salt, cover, and allow to rest for 20 minutes (autolyze).
After this first rest, with a wet hand, pull, stretch, and fold the dough for about a minute. The dough will become noticeably smoother. Cover and rest for 15 minutes. After this second rest, for a second time pull, stretch, and fold the dough with a wet hand. The dough should become nicely smooth. Put in a doubling container, cover and allow to ferment until doubled in size, likely 6-8 hours depending on the temperature in the kitchen. (I used a tall rectangular plastic container about twice the size of the dough, which made it very easy to see when it had doubled.
Line a 7-inch banneton with a liner which is heavily coated with rice flour. Empty the dough onto a floured work surface and form into a ball. Put it smooth side down into the banneton, handing it gently to avoid degassing it. Put the banneton into a plastic bag, seal it, and put it in the refrigerator overnight.
In the morning of day 3, take the banneton out of the refrigerator to warm up. Put the top and bottom of a Lodge combo cooker into the oven and preheat it for 30 minutes at 475 degrees.
Remove the banneton from the plastic bag and sprinkle cornmeal on the top. Put a 9-inch disk of baking parchment on top of the banneton, followed by an upside down plate. Reverse the banneton and plate and remove the banneton. Slash a decorative pattern in the top of the dough. Put it in the bottom piece of the combo cooker and put on the lid. Bake covered for 20 minutes. Then remove the lid and bake uncovered for another 10 minutes. At this point the boule should have a nice brown color, and an instant read thermometer should show that the temperature at the center of the loaf is over 200 degrees. Remove the bottom of the combo cooker from the oven.
Put the cooked boule on a cooling rack and allow to fully cool before cutting, about 20-30 minutes.