Let's get the fundamentals first:
Organic wine is made with organic grapes. Meaning that during the farming bit of grape growing, there are no chemical agents used - this includes pesticides, herbicides and non-organic composts and fertilisers.
Wine producers can choose to be a certified "Organic Wine Farm," which, in South Africa, requires a number of years of stringent inspections by "the suits," and standard and practices must be maintained, AND the farm must pay for the pleasure of being certified.
In these financially squeezing times for wine producers, being fully certified as an organic producer isn't a viable option, but many farms choose to adopt organic crop control practices, sustainable agriculture methods and "minimal intervention" in the cellar (more of this later).
If farms operate to these quite exacting and manually intensive standards, they will be glad to make you aware of them - they are justifiably proud of working solely with nature to nurture their crops.
That's the farming bit, but there are also additional "organic" measures that take place in the cellar, once the grapes have been harvested.
Minimal- or non-intervention is a phrase you'll hear quite often. Simply put, it refers to the absence of artificial stimulants that assist in the fermentation or maturation process - the grapes are allowed to ferment on their own, which may take a little longer than normal due to the natural chemical breakdown of the fruit, and once bottled, only a very small amount of sulphur dioxide (up to half the content that is added to conventional wines) is added.
At this moment, I refuse to go down the rabbit hole of the discussion of the addition or presence of Sulphur Dioxide / sulfites in wines - but there's a well-explained article on the Wine Spectator website here.
There are a number of theories surrounding Organic Wines, most of which are unfounded:
There are fewer than 30 officially certified organic / biodynamic wine producers in South Africa. But many more do operate a strict (un-certified) policy of organic practices, and minimal intervention.
Why not try a wine that contains just grapes?
Here are just a few of the producers we represent; who follow organic, sustainable or minimal intervention practices:
Avondale
Bosman
Botanica
Hughes Family Wines
Jacaranda
Kanonkop
Kleinhoekkloof
Nitida
Radford Dale
Reyneke