To put it simply, organic wines are made from organically grown grapes with no added sulfites. However, nothing is simple.
For this post I am only discussing organic wine in the US. Wines around the world are made “organically” and the regulations for those are different than they are for US producers.
Organically grown grapes have some strict requirements on what can and cannot be used in the vineyard to protect the vines from pests and disease. Organic farming is a huge topic and much more than we will get into today. However, a vineyard must be certified organic for the wines made from those grapes to be used in organic wine.
Once a winemaker harvests these organic grapes and gets them into the winery they have some restrictions on how they can be processed. The main restriction is that wines made organically cannot have added sulfites. Sulfites are the additive in wine that protects it from spoilage. Sulfites are also an allergen so people who are allergic to sulfites might want to try organic wine. The caveat here is that some yeast species produce sulfites during fermentation so… just because wine is made without added sulfites does not guarantee that it will be sulfite free.
There are different certifying bodies for organic wines and they have different restrictions on what can be used so there is variation even within the US. Most will require detailed information about any products that a winery would like to use. They generally do not want inorganic materials added to organic wines. (Inorganic materials meaning things not derived from plants, or animals). However, depending on the certifying body wineries can often request to use “non-organic” products if an organic version does not exist. Usually in winemaking the thing that makes a product non-organic are sulfites that are added to many different winemaking products as a preservative.
Another thing to know about organic wines are that the words on the label matter. If it says something like “wine produced from organically grown grapes” then the wine itself is not certified organic and is probably made with added sulfites.
There are certainly nuances to organic wines, and how they are made. Just keep in mind that organic wines will have minimal sulfites, but may not be sulfite free.