The Oxford Companion to Wine has a long article about it. It "remained little known in the wine world until an increasing number of top-quality producers" adopt

The Oxford Companion to Wine has a long article about it. It "remained little known in the wine world until an increasing number of top-quality producers" adopted it, many of whom learned about it from someone who "makes no claim to understanding how biodynamics works". I, uh, find it difficult to believe … but these actually are top-quality producers. The Companion also notes that many of them do it but prefer discretion. I can see why.