Forbidden to use damaged or altered grapes, violent harvesting systems (machines), clarify with tannin or casein, excessive pressing and crushing, thermal processes without authorization, volatile acidity greater than 0.70 grams per liter, do not use whole natural cork stoppers.
The addition of sulfites is prohibited. Only a total content of fewer than 10 parts per million (ppm) of naturally generated sulfites is allowed. This is one of the main aspects what differentiates organic wines from “made with organic grapes” in which the sulfite content must be less than 100 ppm.
More info here.