At the most basic level, organic wine is made from grapes that have been grown without the use of chemical fertilizers, pesticides, fungicides, herbicides or synthetic chemicals. The main categories of winemaking include: Sustainable, Organic and Biodynamic.
In organic winemaking you will find some very significant differences, both in the winemakers approach to growing grapes and the end result in the bottle. Note - grape growing like any other farming is organic by origin. However, like most other methods of farming the vast majority of vineyards today are not organic. For many winemakers, especially large wineries, it is not cost effective to grow organically, as far too many things can go wrong throughout the year that can easily destroy their grape crops.
Chemical fertilizers are predominantly used to remove vineyard destroying diseases. Organic wines are produced by using only organically grown grapes. No chemical fertilizers etc..., etc of any kind are allowed on the vines or in the soil of the vineyards claiming to be organic. Strict rules govern the winemaking process such as hand-harvesting the grapes, the types of yeasts that can be used during fermentation and storage conditions in the wineries of all imported and domestic wines that attain organic certification.
Organic winemakers refrain from all chemical substances used to stabilize conventional wines such as sulphites. It is important to remember that sulphites are a natural by-product of the fermentation process and that it is impossible for any wine to be completely free of sulphites, as fermenting yeasts present on all grape skins generates naturally occurring sulphites. Organic wines may have naturally occurring sulphites, but the total sulphite level must be less than 20ppm in order to receive organic certification. Wines labelled 'organic' cannot contain added sulphites. Wines that have added sulphites, but are otherwise organic, are labelled 'wine made from organic grapes.'