It's difficult to determine how many vineyards worldwide engage in the biodynamic philosophy. While some are certified as practicing biodynamic viticulture, many dabble with different aspects of it without fully meeting certification parameters. Also, since biodynamic viticulture is a growing phenomenon, more and more practitioners are popping up all the time.
France is the biggest contender at the moment, but other countries where biodynamic viticulture is gaining popularity include Italy, the United States, Australia, Chile and New Zealand, while vineyards in many other countries are also jumping on the bandwagon.
Vintners interested in converting to biodynamics have to keep in mind that it's not really about following a set of established guidelines or learning some simple new growing tricks. Rather, it's more about adopting a lifestyle and a set of beliefs -- about listening to a particular piece of land and becoming tuned in to what it needs to thrive.
It's also at least partly about community. Complex farming practices and soil preparations are easier to learn with help from someone who's already started down the path of biodynamics, as opposed to attempting to dive in headfirst without guidance or advice. Consultants can also be hired to help get things running smoothly, but beyond that, a growing store of experience is often the best tool of the trade.
Once you've started to get the hang of it, you can go for certification. In the United States, for example, this typically involves spending a couple of years becoming certified as organic through the United States Department of Agriculture's National Organic Program. Then the farm needs to work toward biodynamic certification, often with a company such as Demeter, which annually inspects a growing number of biodynamic agricultural setups.