Depending on the humidity where you live, it may not take a full 8 cups of flour. When enough flour has been added, the dough will gather to itself and clean the sides of the bowl as it is kneaded. Watch for this moment to happen sometime between cups 7 & 8 cups of flour. In very humid climates, it may take a full 8 cups of the flour (maybe even a little more...be careful). The dough will be soft and tacky, but should not be gooey, overly sticky, or heavy.