Separating out the natural and organic knowns from the unknowns, here's a rough list of natural winemakers and wineries:
Natural Winemakers Using Certified Grapes
• Cotturri - ALL WINES (including estate and purchased)
• Natural Process Alliance (Sunhawk Red only)
• Old World Winery - one wine (DiRicco Vineyard - Sauvignon Blanc)
• Radio Coteau - ask which ones
Using Uncertified Grapes But Who Say They Are Organic
These have their own vineyards:
• Bunter Spring Winery (Bunter Winery estate grapes only; they also make wines under the Spring brand with nonorganic, purchased fruit)
• Clos Saron
• Edmunds St. John
• La Clarine
Negociants - i.e. they buy grapes from a variety of growers; I have not found any with certified fruit (but this changes all the times so I would ask the wineries themselves about any particular wine you want to know about)
• Broc Cellars
• A Donkey and Goat
• Wind Gap Wines
Please send me info on any more that are coming up. I'd like to make a Google Map of them all.
I would also add that if you were a true purist and using Alice Feiring's criteria for real natural wine, you would eliminate wines that were made from others' grapes...which would knock out Coturri (many if not most of their grapes are purchased) leaving pretty much only Ambyth Estates (which grows all their own grapes) as the only natural winery growing almost all their own grapes and making all but one of their wines with certified grapes.
A lot of biodynamic wine producers should be listed here as well, but they do use a little tiny bit of sulfite - including Cowhorn, Grgich (estate wines are all BD), Beckmen, Verdad/Qupe (estate grown wines) and others.