Hello Sophie! You definitely should not rinse your rice when making risotto, and your intuition about the starch is completely correct.
Risotto rice varieties, such as Arborio, Carnaroli, or Vialone Nano, are specifically chosen because they are rich in surface starch known as amylopectin. When you cook risotto and slowly ladle in warm broth while stirring, those starch granules rub off the grains and dissolve into the hot liquid. This natural starch is what emulsifies with your broth, butter, and cheese at the end to create the signature velvety, creamy texture that defines a proper risotto.
If you were to wash the rice beforehand, you would rinse away that vital coating of surface starch. As a result, the cooking liquid would not thicken properly, and you would end up with a watery or loose rice dish instead of a rich, creamy sauce coating each grain.
Additionally, keeping the rice dry allows you to properly toast the grains in oil or butter at the very beginning of cooking. Toasting creates a light protective barrier around the core of the grain, locking in structure so the rice stays pleasantly firm and al dente without turning mushy. Enjoy making your dinner!
