Making udon from scratch can be a little tricky, but it’s a fun project, and even if your first efforts look a little rustic, they’ll still taste good. Once you get the hang of it, you’ll be able to turn out supple, springy noodles worthy of a restaurant.
Knead the dough aggressively in the bowl, using the weight of your body (it helps if the bowl is below your waist). It will be quite firm. Knead 5 minutes and shape into a ball. Place in a plastic bag. Squeeze out air and smash ball into a pancake shape about 5 inches in diameter. Let rest 30 minutes at room temperature.