Reactivate your starter the day before you plan on building the levain. A good time to do this is right before bed, to allow the starter six to eight hours to become bubbly and active. You will need 25 grams for the levain and at least 20 grams left over for maintaining your original starter/main culture.

Build the levain: This is done in three stages. For the morning levain feeding, use a kitchen scale to weigh 25 grams of active starter in a clean 500-milliliter jar. Add 30 grams of warm water, 15 grams of brown rice flour and 15 grams of buckwheat flour, for a total weight of 85 grams. Mix the ingredients well.

For the afternoon levain feeding, put the 85 grams of levain from the morning levain feeding in a clean 750-milliliter jar and add 55 grams of warm water, 25 grams of brown rice flour and 25 grams of buckwheat flour, for a total weight of 190 grams. Mix the ingredients well.

For the evening levain feeding, late in the evening, put 190 grams of levain from the previous two feedings in a four-cup (one-liter) proofing bowl. Add 120 grams of warm water, 50 grams of brown rice flour and 50 grams of buckwheat flour, for a total weight of 410 grams. Mix the ingredients well, cover the levain in the bowl with the bowl’s lid and leave it overnight to ferment for eight to 10 hours.

In a large bowl, weigh the sorghum flour, oat flour, millet flour, buckwheat flour, tapioca starch, brown rice flour, salt, pumpkin seeds and sunflower seeds.

In a medium bowl, combine the warm water, olive oil, golden syrup and brown sugar. Stir in the flaxseed and psyllium husk to form a gel. Immediately whisk the psyllium gel to prevent lumps from forming, then whisk in the levain and caraway seeds.

Add this gel-levain mixture to the flour blend. Mix the dough well by hand, or with a kitchen mixer fitted with a dough hook running at medium-low speed, until all the ingredients are fully incorporated.

Form the dough into a ball, then place it in a four-cup (one-liter) proofing bowl. Cover the bowl with its lid and place the bowl in the oven with the light on. Let the dough rest for 30 to 60 minutes, or until the dough begins to rise a little.

Place the covered bowl in the fridge overnight for the bulk fermentation.

The next day, remove the dough from the fridge and leave it at room temperature for about 30 minutes, until it is warm enough to work with.

Liberally dust a seven-inch (18-centimeter) round banneton with the white rice flour.

Lightly dampen a work surface with water. Transfer the dough to the prepared work surface. Knead the dough with wet hands for two to three minutes, and then shape it into a ball.

Sprinkle a little white rice flour on the dough’s surface, then repeat the kneading process for about one minute. With cupped hands, drag the dough in small circles to shape it into a smooth ball. Pinch, seal and smooth any seams in the dough. Scoop the dough up with a bench scraper and gently place it seam side up in the prepared banneton.

To bake this bread in a loaf pan, line the pan with Gefen Parchment Paper, leaving overhanging “handles” of parchment paper on each side of the pan. After shaping the dough into a ball, roll it with the palm of your hand a few times to create an oval shape, and then place it in the prepared loaf pan.

Place the dough, still in the banneton or loaf pan, inside a reusable plastic bag and let it rest at room temperature—ideally about 72 degrees Fahrenheit (22 degrees Celsius)—for three to five hours. The proofing time depends on the temperature of your kitchen. If the temperature is a little colder, place the dough in the oven with the light on. In the summer warmth, the dough can be left on the counter, and it may benefit from less proofing time. When the dough has proofed enough, it will have risen and will feel soft, puffy and spongy on the sides and in the center.

If you will be baking the bread in a Dutch oven, preheat the oven to 450 degrees Fahrenheit (232 degrees Celsius) with a Dutch oven inside.

Meanwhile, cut out some parchment paper for the dough to sit on. Place the parchment paper on top of the dough, which should still be in the banneton. Flip the banneton upside down, so that the parchment paper is underneath to hold the dough, and remove the banneton. If baking in a loaf pan, leave the dough in the pan.

Lightly dampen the surface of the dough with wet fingers. Sprinkle some white rice flour on the dough, then evenly spread the flour around the top of the dough with your hands.

Score a design on top of the dough.

To bake in a Dutch oven: Gently slide the parchment paper with the dough into the Dutch oven. Cover the Dutch oven and bake the bread for 25 minutes. Remove the Dutch oven’s lid, reduce the oven’s temperature to 400 degrees Fahrenheit (204 degrees Celsius) and bake the loaf for 35 minutes.

Reduce the oven’s temperature to 350 degrees Fahrenheit (177 degrees Celsius) and remove the loaf from the Dutch oven. Place the loaf on the oven’s center rack and bake it for 10 minutes, or until the loaf feels firm.

To bake in a loaf pan: Preheat the oven to 450 degrees Fahrenheit (232 degrees Celsius). Bake the loaf for 35 minutes, then reduce the oven’s temperature to 400 degrees Fahrenheit (204 degrees Celsius) and bake the loaf for 30 to 35 minutes. Remove the loaf from the pan.

If the loaf is soft and undercooked on the bottom, place it directly on the oven’s middle rack and bake it for 10 minutes at 350 degrees Fahrenheit (177 degrees Celsius).

Place the hot sourdough on a wire rack to cool for at least two hours before slicing it.

Wrap the bread in a tea towel or beeswax wrap and store it on the counter for two to three days. If your sourdough begins to dry out too quickly, it is best to slice and freeze the remainder. The sourdough will last in the freezer for up to three months.