Organic viticulture is a form of agriculture that relies on crop rotation, green manure, compost, biological pest control, and mechanical cultivation to maintain soil productivity and control pests, excluding or strictly limiting the use of synthetic fertilizers and synthetic pesticides, plant growth regulators, livestock feed additives, and genetically modified organisms.
Herbicides, insecticides, and most fungicides are prohibited. Chemicals used must be naturally occurring and not poisonous. This allows some sprays to be used that are not harmful, and not taken up by plant tissue (such as copper and sulphate).
Anything you add to the land must also be organic, particularly fertilizer.
It is possible to convert a vineyard to become certified organic. The process takes a minimum of three years, under the inspection of an independent inspector contracted to Australian Certified Organic.
Biodynamic viticulture stems from the ideas and suggestions of Rudolf Steiner some 80 years ago. Its principles and practices are based on his spiritual/practical philosophy, called anthroposophy, which includes understanding the ecological, the energetic, and the spiritual in nature.
Biodynamic agriculture conceives of the farm as an organism, a self-contained entity with its own individuality, and as such has much in common with organics. Methods that are unique to the biodynamic approach include the use of fermented herbal and mineral preparations as compost additives and field sprays and the use of an astronomical sowing and planting calendar.
Organic winemaking principles are based on the absence of non-organic chemicals in any part of the wine production process.
Certified organic wine can only be made from organic grapes. When a label says "organic", in Australia it means the wine has met certain standards that are set by Australian Certified Organic (a government agency), and inspected/audited by an independent inspector contracted to that agency. (Different nations have their own certification criteria, so what's organic in one country may not be so in another).
Cleaning agents like chlorinated compounds are not permitted, and organic wine cannot be mixed with non organic wine.
In Australia, the debate over organic winemaking principles revolves largely around the use of sulphites in the winery, and its 'natural' presence via the fermentation process.
Organic doesn't mean preservative-free. The common preservative –220- is allowed in organic wines to be at the level of 125 parts per million. (Most modern wineries, whether organic or not, operate below or around these levels)