The claim is simple: the same wine tastes better on a fruit day than on a root day. Wine professionals have argued about it for years. Here's what we actually know.
The claim
Followers of the biodynamic calendar say that on fruit days wines are more expressive, fruity and open, and that on root days they turn closed, earthy and tannic. Some retailers and critics have reportedly scheduled tastings around it.
What the research found
The best test so far was published in PLOS ONE in 2017 by Wendy Parr and colleagues in New Zealand. Nineteen wine professionals tasted twelve Pinot Noirs blind, each wine four times: twice on fruit days and twice on root days. They scored each wine and described it from a list of terms.
The researchers found no meaningful difference between fruit-day and root-day tastings, in either the scores or the descriptions. Their conclusion was that any effect people notice is more likely down to expectation than to a change in the wine.
Source: Parr, W. V., Valentin, D., Reedman, P., Grose, C. & Green, J. A. (2017). Expectation or sensorial reality? An empirical investigation of the biodynamic calendar for wine drinkers. PLOS ONE 12(1): e0169257.
Why people still swear by it
- Expectation is powerful. If you believe today is a great day for wine, you pay more attention and enjoy the bottle more. That's a real effect on your experience, even if the wine hasn't changed.
- One study isn't the last word. It covered one grape variety, a small panel and a few days. Weather, air pressure and mood all vary, and a single experiment can't rule everything out.
- It's a lovely ritual. Planning the special bottle around the Moon makes the occasion. Plenty of people follow it for that alone.
Test it yourself
You don't need a lab to run your own version:
- Pick a wine you can open twice, with two bottles or a wine preserver.
- Taste once on a fruit day and once on a root day, at the same time of day and the same temperature.
- Have someone else pour, so you don't know which day it is, and write your score down before anyone tells you.
Or let the crowd decide
Moonvine lets you share your tasting experience. Whenever you have a glass, vote tasting great or tasting flat. Your vote counts toward that exact window, alongside everyone else's. The app shows the crowd’s verdict for that window. These self-reported votes reflect individual experiences and expectations; they do not establish that lunar timing changes wine taste.
Questions
Is there scientific evidence for the biodynamic calendar?
For wine tasting, the only controlled blind study (Parr et al., PLOS ONE, 2017) found no significant difference between fruit and root days. There is little rigorous research either way on the farming side of the calendar.
Why do wine shops use the biodynamic calendar?
Some believe wines show better on fruit and flower days, and choosing a "good" day costs nothing. Expectation may also make tasters more generous.
