When a label says “organic,” it means the wine has met certain standards that are set by a government agency. Different nations have their own certification criteria, so what’s organic in one country may not be so in another. One main difference is the use of sulfites, in the US for instance, an organic wine cannot contain sulfites, while in Europe, sulfites (which is a natural product) is allowed in minimum quantities.
Biodynamic takes organic farming to a more spiritual level. The father of the movement is widely regarded as being the Austrian anthroposophist Rudolph Steiner (1861-1925) who gave a series of agricultural lectures in 1924 setting out the broad principles. His best known followers since then has been Maria Thun (1922-2012) who published an annual biodynamic gardening calendar.
Many wineries that are technically organic still choose not to be certified. There are many reasons for this. Some do not want the added costs and bureaucracy of registering or some others cannot as the surface of their vignards is small and can contain every small traces of pesticides used in neighbor vignards. Whatever the case, they are not allowed to use “organic” on their labels, but for us, after careful selection, we consider them natural.