In a small bowl, whisk collectively 1⁄4 cup (60 grams) warmth water, yeast, and 1⁄2 teaspoon (2 grams) sugar. Let stand until foamy, 5 to 10 minutes.
Throughout the bowl of a stand mixer fitted with the dough hook attachment, combine yeast mixture, flour, lukewarm water (105 grams), salt, and remaining 1 teaspoon (4 grams) sugar. Beat at low velocity for 5 minutes. (Dough will look dry at first nevertheless will come collectively later.) Add 4 teaspoons (20 grams) olive oil; beat until blended. (Use your fingers to help incorporate, if needed.) Add remaining 1 tablespoon (15 grams) lukewarm water; beat at medium-low velocity until dough is simple and elastic, 6 to 7 minutes. (The dough is good when it’s elastic when pulled and troublesome to tear.)
Find yourself dough onto a frivolously floured ground; attain beneath one side of dough, and gently stretch and fold dough over to center. Repeat on remaining 3 sides, and sort a barely flattened rectangle. Place, seam side down, on a frivolously floured board; cowl with plastic wrap, and let stand for half-hour.
Coat a 15×11-inch baking pan with 2 tablespoons (28 grams) olive oil.
On a frivolously floured ground, roll out dough proper right into a 13×9-inch rectangle. Change dough to prepared pan. Cowl with plastic wrap, and let rise in a warmth, draft-free place (75°F/24°C) for half-hour.
Stretch dough into corners until it covers complete ground of pan, leaving no edges free and taking care to eliminate diverse air bubbles beneath dough. Cowl and let rise in a warmth, draft- free place (75°F/24°C) for 1 hour.
Generously flour ground of dough, and make deep dimples shut to 1 one other using your fingertips (exclude your thumb and pinky finger and try to carry the palm of your hand going by means of the dough’s ground). Pour Brine and remaining 11⁄2 tablespoons (21 grams) olive oil evenly over ground. Mix Brine and oil successfully alongside along with your fingers, utterly defending ground. (Be careful that the Brine does not go beneath the dough.) Cowl and let rise in a warmth, draft-free place (75°F/24°C) for 1 hour.
Preheat oven to 450°F (230°C).
Bake until golden brown, 15 to 17 minutes. Invert focaccia onto a wire rack, and brush bottom and prime with extra-virgin olive oil. Let cool on a wire rack to take care of it crispy.