Mix it up
Spread your fingers and move both hands together rapidly in a figure 8 to mix flour and water quickly and evenly (it’s crucial to move fast; otherwise udon will have dry spots and may crack). As you mix, sweep sides and bottom of bowl to blend in any dry patches. When flour looks like cornmeal, add remaining water. Mix as before; it will begin to clump (see photo). Again sweep bowl to mix in any dry patches, and mix until a dough starts to form.