Opponents have excoriated natural wines just as the establishment lampooned hippies in the 1960s, citing bad hygiene in production, stinky bottles and, most of all, the lack of a rigorous definition of what makes a wine “natural.” They take issue with the implied criticism in the term: If your wine is natural, what does that make mine?

I have always considered the lack of a definition of natural wine to be a great strength. Despite the mainstream wine industry’s defensiveness, natural wine has never been an organized movement. It’s an ideal, rather than a set of rules: to make wine with an absolute minimum of intervention and manipulation in the vineyard or in the cellar.

Practically speaking, that means farming organically, biodynamically or by using some variant of the two. In the cellar, no overt manipulations or additives are allowed beyond a minimal amount of sulfur dioxide, which has long been used as a stabilizer and preservative, and all processes should be communicated transparently. Yet, even within the natural-wine world, the meaning of the ideal is debated fiercely.

Regardless of a precise definition, the significance of natural wine has been its role as an insurgency, inspiring the public to think more about what goes into the wines it is drinking and, through commercial pressure, to force the mainstream wine industry to confront and modify its own practices.