New rice is better than old when making Teochew porridge. New rice is rice that's harvested recently. It has a high starch content. Old rice is less starchy, because it has been harvested and stored for some time.
How to tell if your rice is old or new?
New rice feels moist and smooth, like baby skin. Old rice is dry and a bit rough. Or you could just look at the packaging for the rice. It