Inspired by the focaccia made in Liguria by Samin Nosrat in Netflix’s “Salt Fat Acid Heat” (based on Nosrat’s book by the same name), this version is made using my trusty sourdough starter rather than packaged yeast.

This is meant to be a fairly dense-textured bread. If you want it a bit fluffier, you could shorten the 2nd ferment by a couple of hours and add that time to the resting period after adding the brine.

Ingredients (for levain)

100g sourdough starter
200g lukewarm water
65g whole wheat flour
135g white flour

Ingredients (for dough)

400g levain
500g lukewarm water
21g sea salt
800g white flour

Olive oil
White Flour

Ingredients (for brine)

250g water
12.5g sea salt

Method

Mix Levain

Bring your stored starter out of the fridge and allow to come up to room temperature
In a 1L glass measuring cup, combine all ingredients for levain and mix well.
Cover with a damp tea towel and leave to ferment at room temperature until doubled in volume (for me, it starts at about 400 ml and grows to 800 ml in about 7-10 hours)

Mix Dough & Bulk (First) Ferment

When the levain has doubled in volume, put 100g back into storage in the refrigerator. The remaining 400g will be used for the dough.
In a large mixing bowl, dissolve 21g sea salt in 500g water, then mix in the starter. Combine well - note that the starter won’t fully “dissolve”. Just mix it reasonably well.
Add in 800g white flour, and mix until well combined. Cover the bowl with TWO damp tea towels and allow to rest for 20 minutes (this step is called the “autolyse”).
After 20 minutes, on a lightly-floured or (olive) oiled countertop with floured or oiled hands, knead the dough for 5-10 minutes. If flouring your hands, you’ll need to add small amounts of flour as you work because the dough will be quite wet and sticky. If you oil the countertop and your hands, you’ll be able to use less flour, but more oil will be worked into the dough. Both work - up to you which you want to do.
Rinse out your bowl, then lightly dress it with olive oil. Place the kneaded dough in the bowl and cover with TWO damp tea towels. Allow to bulk ferment for about 4 hours at room temperature.

Shape Dough & Second Ferment

After four hours, prepare two 10x15” baking sheets by generously oiling them with olive oil.
Divide the dough into two equal portions, flatten them out in the baking sheets, then flip over and flatten out again. Note that they may not quite fill the baking sheets at this stage, but that’s OK - they should fill out during the second ferment.
The top of the dough should be well oiled - if not, rub a bit more oil over the top. Cover both sheets with plastic wrap and allow to ferment at room temperature for 10-12 hours. At the end of this stage, the dough should have filled out the baking sheets and risen a centimetre or two above the rim.

Prepare and Brine Dough for Baking

After the second ferment, remove the plastic wrap from the dough. Mix the sea salt and water for the brine and set aside.
With your first three fingers (index, middle and ring) held slightly spread apart, press regular rows of divots into the top of each focaccia, right to the bottom of the dough but without breaking through to the baking sheet (this might take a bit of practice to get right).
Pour the brine over both sheets of focaccia, filling the divots. Discard any extra brine.
Allow to rest uncovered at room temperature for 45 minutes to an hour while the oven preheats.

Baking The Focaccia

Preheat the oven to 425 F while the focaccia is resting.
Bake at 425 F for 20-25 minutes, until the surface of the focaccia is nice and golden.
Turn the heat down to 375 F and continue to bake until done (when the internal temperature of the focaccia is around 212 F, around 10-15 minutes).
Remove from the baking sheets and cool on a cooling rack.