I made this at a cooking school in Istanbul
Swapping regular table salt for flaked sea salt alters the moisture extraction rate, requiring a full tablespoon instead of a teaspoon to properly draw out water from the squash. Zucchini contains up to ninety percent water, which acts as the primary obstacle to achieving a crisp exterior during frying. Removing this liquid protects the flour binder from turning gummy.
Grate the zucchini on a box grater using long, diagonal strokes to produce uniform strands rather than mush. Squeezing the grated vegetable firmly inside a clean cotton tea towel removes excess moisture before it ever touches the mixing bowl. Without this extraction step, the batter thins out too much and absorbs excessive oil during frying. Heat the sunflower oil to 375 degrees Fahrenheit in a heavy cast-iron skillet to ensure an immediate crust forms on contact. Maintain oil depth at roughly one-quarter inch to fry evenly without submerging the patties.