“Biodynamic practitioners envision plants as existing in a ‘middle kingdom’ influenced from below by the forces of the earth and governed from above by solar and astral forces,” writes Karen O’Neill in The Wine Bible. “Thus, vineyard practices such as pruning are done according to the movement of the moon through the twelve houses of the zodiac.” In a biodynamic calendar, each day is linked to an element—earth, water, air, and fire—and stages of plant growth on a lunar calendar, such as fruit days, leaf days, root days, and flower days.

This may all seem gauzy and ephemeral, but wineries with biodynamic certification have to uphold a long list of standards. Certified-biodynamic wineries reserve at least 10% of their land as biodiversity reserves, and harvested crops must rotate every two years to preserve soil health. Vineyards must also meet specifications for water conservation and cannot use synthetic products for disease, pest, and weed control. Incorporating livestock is encouraged but strictly regulated. Certified-biodynamic wines can contain up to 100 ppm sulfites, which is more than is allowed for organic wines in the U.S. but in keeping with EU requirements.

“Many wine consumers seem to have internalized a notion that biodynamics is sort of organics times two or something, but this is a grave simplification,” says Aaron Ayscough, author of The World of Natural Wine and the newsletter Not Drinking Poison. Instead, it’s perhaps helpful to think of organic certification as a checklist and biodynamics as an ideology, albeit one that also involves an array of carefully monitored specifications.

What is natural wine?

Ask 10 people what natural wine means and you’ll likely get 10 different answers. It’s hardly their fault. Unlike terms like organic and biodynamic, there’s no certification process for natural wine in most of the wine-producing world.

Generally speaking, natural wines are considered those made with sustainably farmed grapes, wild yeasts, and without any additives, including acid, sulfites, or megapurple, which winemakers might otherwise use for color. “Natural wine is what we call the work of the loosely organized subculture of estates that insist on high standards of purity in cellar practices as well as farming practices,” says Ayscough.