The first step in making fu is the same as for seitan (seasoned wheat gluten): wheat flour is mixed with water and kneaded to activate the wheat's natural gluten. After resting for an hour or so, the dough is rinsed to remove the starch (carbohydrate) and bran, thus concentrating the gluten (protein) of the wheat. Up to this point, the process is the same as for making seitan. However, the rubbery gluten is next mixed with an equal amount of wheat flour. The dough is rolled out, cut into strips that are wrapped around long metal poles, and baked until slightly browned. Depending on the variety of fu being made, up to three more strips of dough may be added and baked, one layer at a time. The fu is then lightly steamed to soften its texture and leaven it. Finally it is sliced, dried, and packaged.
There are several types of fu based on shape. The most common of these are kuruma, zeni, zenryu, and shonai fu. In Japanese kuruma means "wheel" and zeni, "coin." Both are doughnut shaped, but kuruma fu is much larger. Zenryu fu is an intermediate-sized, doughnut-shaped whole wheat variety. Shonai fu is a thin, flat variety. While all the other types are a combination of wheat gluten and unbleached white flour, Mitoku's round Zenryu Fu is made with half gluten flour and half whole wheat flour.