Is Biodynamic winemaking a load of bull?


"Our organic and biodynamic credentials have roots as deep as our decades-old vines because we firmly believe it is our responsibility to improve the land for future generations. Healthy soils lead to a healthy ecosystem and that rewards both us and you with the gems from which we craft our fine wines." Gemtree


Who better to ask than Mike and Melissa from Gemtree who have provided a fascinating insight into their world of biodynamic winemaking…


The Principles

Firstly, and to bridge the gap between those readers who are and are not ‘in the know’ of biodynamics, how would you describe its principles in layman’s terms?

I describe it as being the same as organic but there is more to it.  The main focus is on soil fertility and a recognition that the moon has a gravitational effect on the earth.  Just as the lunar cycle has an effect on the tides it also has an effect on nature and even us humans.  Biodynamics is a holistic approach to farming – it’s not just about looking after the crop you are growing but the entire farm or land you are custodian of.

You often describe biodynamic practices as the extension of organic farming. What are the main benefits associated with biodynamics that you can’t achieve with organic practices alone?

Timing of operations in tune with the lunar cycle to achieve maximum benefit.  For example, spraying out 500 (horn manure, a soil activator) when the moon is descending and earthly forces are drawing in, is the optimum time for that preparation. Likewise, we apply preparation 501 (ground clear quartz that aids in photosynthesis and uptake of soil minerals) when the moon is ascending.  Another example is harvesting our grapes on a fruit day according to the astro calendar.  This is when the fruit will have maximum concentration and flavour.  If I was a potato farmer, planting my crop on a root day will achieve a better result than planting on a leaf day (Maria Thun devoted her life to researching this phenomenon and the results are in her book).

Are there any biodynamic principles that you feel sceptical about?

I haven’t had much luck with weed teas. 

I’m also yet to test out peppering to deter pests, so until I can prove to myself that it works, I’ll remain a little sceptical!  I haven’t really delved into the area of radionics either.   I would describe myself as more down to earth rather than spiritual and I need proof before I will believe something.

What would you say are the primary misconceptions about biodynamics today and can you elaborate to disprove the misunderstandings?

That it’s some kind of witchcraft and we spray moon juice!  Also, that the lunar cycle does not have an effect on what happens on our planet and there are no tangible benefits.

Maria Thun’s research is proof that the lunar cycle and timing of operations has a role to play in farming.

We ran our own trial here at Gemtree for 6 years in a Cabernet Sauvignon block comparing conventional (red), biodynamic and organic (green).  The level of organic matter in the green areas was higher than the red, which is no surprise and there are so many benefits that come with higher levels of organic matter.  

The trial also comprised a sensory component where we tasted the wines from the different plots.  It was a blind tasting that involved winemakers and researchers and the biodynamic wine was picked as the one with best flavour.

Do you take a different approach when explaining biodynamic principles to a) customers b) fellow winemakers and c) farmers?

Not really.  Biodynamics is for everyone and can be used in both home gardens and farms. Biodynamics also encourages people to think more about the produce they buy, how it is grown, how much nutrition it contains and how much damage is being done or not, to country (as Aborigines refer to the land) by farming.


Your Own Experience

What were your main concerns and doubts when you converted the vineyard to biodynamic?

My main concern was pests and diseases and how we would control them.  I was also concerned at the drop in yield that occurred while we were trying to work out how much weed control was necessary.  As it’s turned out, I had more problems with pests and disease in the vineyard when the vineyards were conventionally farmed.  Our yields are on a par with the rest of the region and quality has improved. 

We understand it took a lot of persuading, but you managed to convince Melissa’s dad to introduce biodynamic practices in a part of Gemtree’s vineyards back in 2000s. What do you think were the deciding factors which ultimately swayed the opinion / decision / converted a straight ‘no’ to ‘let’s give it a try’?

There were a number of factors that came into play:

  • Trialling the practices in a block of Tempranillo to prove it worked
  • Dad’s good friend David Paxton (of Paxton Wines) had already converted to biodynamics and we were able to say “David Paxton wouldn’t be doing it if he wasn’t convinced it works”
  • A lot of arguments and continued persistence!  Determination.

Which principles do you find most effective in your own vineyards and which practices (if any) have failed over time?

Removal of herbicides and pesticides (poisons) from the eco-system is the first and critical step, then applying remedies to help repair the damage done. Preparations 500 and 501 were sprayed 4 times a year and compost applied annually to build up organic matter levels in the soil and restore equilibrium to the soil food web and atmosphere.  I also use a lot of seaweed as a plant tonic and believe this builds resilience.

Weed teas failed and I’m yet to find an effective method for dealing with snails.    It also takes longer for a newly planted vineyard to become established taking 4 years to get a first crop instead of 3.

Practically speaking, how difficult is biodynamic farming as opposed to organic and traditional methods?

Are there any elements which make farming life easier at all?

The number one thing that puts people off is dealing with the weeds.  We now spend a lot more time on weed control using sheep which involves moving them around a fair bit as the best results occur when they are kept in small ‘cells’ and moved frequently.  The sheep are our post-harvest and dormancy weeders and during the growing season we use mechanical methods of weed control which include a dodge plough, finger weeder, knife and undervine mower depending on the soil type and situation.

As I mentioned previously, our vines are more resilient and we have less pest and disease problems which makes life easier.


How biodynamics affect the wine

Clearly, one way of showcasing the benefits of biodynamics (or even converting the sceptics) is to open a bottle of Gemtree. For us, the sense of purity and balance is clear to see. Could you please describe a handful of major benefits of biodynamics and how they translate to the wine’s structure and flavour?

Would it be fair to say that you produce ‘natural wines’ in the most complete sense or is this a rather trendy concept?

Since converting to biodynamic farming the vines are producing grapes that are more balanced and the wines ferment cleaner, meaning they don’t require fining to remove unwanted compounds.  The wines now have an energy about them waiting to be unleashed in the glass.  This is particularly evident in the Subterra Shiraz that ages in a barrel under the ground and the Luna Temprana Tempranillo as both these wines are preservative free resulting in pure expression of fruit and terroir.

“Natural wines” can be a fairly broad term. We would say that we make biodynamic and organic wines, and we farm naturally. Mike and the rest of the winemaking team love the curiosity of winemaking, and innovation in the wine cellar keeps the wines interesting!

History and Future

Many people refuse to believe in biodynamics due to its close relationship with astrology and holistic pseudoscience. However, it is also linked with practices of ancient agronomy and it conveys a strong focus on soil science. Do you think that biodynamics have the potential to become an academic science?

Yes I do.  The evidence of the benefits is clear to me and also from many articles I have read.  For example, results from a recent study were published in the Biodynamic Agriculture Australia Newsletter. 

Comparison trials between biodynamic and organic growing on the one hand, and conventional on the other, were carried out in the late 1990’s with winter rye by the Research Institute of Organic Agriculture in Switzerland (the DOK trial). The six sets of results are as follows:
Root penetration intensity (root length 0-55mm depth)
Organic: 3% more than conventional
57% more than conventional
Weight of earthworms (gram/m2)
Organic: 30% more than conventional
40% more than conventional
Activity of microorganisms
Organic: 43% more than conventional
61% more than conventional
Symbiosis with root fungi (proportion of roots with arbuscular mycorrhizae)
Organic: 33% more than conventional
40% more than conventional
Nitrous oxide emissions (N2O measured throughout the crop rotation)
Organic: 25% less than conventional
43% less than conventional
Soil crumb stability (proportion of stable aggregates > 0.25mm)
Organic: 4% more than conventional
25% more than conventional
Source: German Biodynamic Journal, Lebendige Erde, as translated and reproduced in Star & Furrow, Issue 134, Autumn 2020, p.24


Do you think there is still much left to discover and explain? Is this a growing area of research / interest?

Yes I do.  Not enough research has been done on the positive benefits of biodynamic farming.  I think it is a growing area of interest for many. Humans have done so much damage to our planet and people like myself are concerned and want to take actions in their lives that will have a positive impact instead of a negative one.

Do you see more Aussie producers (wine growers and food farmers alike) converting in the near future?

Yes definitely.  The level of interest from when we first started using biodynamics 15 years ago to now is increasing which is why we run tours teaching people about the biodynamic methods.

Sadly, organic and biodynamic farming seems unlikely to take over the world where commercial farming and the need for scale take priority over quality or even over the environment. Do you think there is a possibility of achieving a golden mean or are they destined to remain polarising opposites?

That is a tough question!  Will good triumph over evil is what you are asking.  I recently watched a documentary on Netflix called Kiss the Ground.  My wish is that everyone in the world involved in politics and agriculture watches it, but that won’t happen.  The film is about how soil management can have a major impact on reducing climate change and soil erosion.

It looks back on past mistakes and what we can do to make things better in the future.  It had such an impact on Mike and me that we hired a venue so that our whole team could watch it.

With the global commitment towards a greener future, which organic or biodynamic practices have a realistic potential to be implemented in farming across the globe?

My hope is there will be less reliance on herbicides and farmers will find a more environmentally friendly way of managing weeds.  Compost has so many benefits – recycling waste to reduce landfill that is then put back on the land to improve it.  Using more biological methods of pest and disease control.

If you were in charge of environmental health globally, what other steps (not necessarily relating to farming) would you introduce in order to help create a greener future? 

I just bought a hybrid vehicle and I love it!!  I’ve been waiting for something suitable that I could drive 

in the vineyard to come on the market.  Hybrid and electrical vehicles should be mandatory moving forward.

Multinational companies should have to apportion a percentage of profits to schemes that help the environment like carbon neutrality and reducing waste.  Gemtree has just signed up to CleanHub – a program with a mission to reduce plastic waste going into the ocean globally.


Gemtree Wines Phantom Red Blend Ten 2019

97-98 Points - Stuart McCloskey “A blend of 61% Cabernet Sauvignon and 39% Mataro, which and despite its tender age is singing wonderfully from the decanter (we sampled after 6 hours). The bouquet is incredibly pure and defined by sweet blueberry, mulberry, dried spice, violet, pen ink and a flicker of mint. The palate is wonderfully structured with grippy tannins – a slight huskiness which will soften with some bottle age. Without stating the obvious, there’s a lovely natural feel to the wine. There’s a succulence and coolness to the fruit which I find particularly attractive. Dark plums are in abundance – I detect a little cold metal too. Clearly, a super-classy wine filled with pedigree. Not only a triumphant Biodynamic wine, but a wine which exemplifies modern Aussie winemaking. Served using Zalto Bordeaux glassware. Drink now to 2035+”

97+ Points - Magdalena Sienkiewicz "Blackcurrants, mulberries and eucalyptus provide a strong hint of Cabernet Sauvignon which makes up the majority of the blend along with 39% Mataro. Although lush fruit dominates the nose, there is great depth and wonderful freshness which screams quality. The palate bursts with fruit, spices and herbs which show great foundations for a long, bright future ahead. Good grip from the tannins, yet they travel through the palate with a velvety touch. Great wine with lots of interest and in fact, I’m dying to see it unfold and flourish. Decant for at least 6 hours or hide it in the cellar, as this will develop beautifully over the next decade or more (in the right conditions). Sampled using Zalto Bordeaux glassware."

£32.95 per bottle


Gemtree Wines Small Batch
Cabernet Sauvignon 2019

97++ Points - Stuart McCloskey “This comes across more serious and restrained compared to the Grenache – I would recommend 4-6 hours in the decanter. This is powerful and grown-up with a brooding bouquet which does take time to develop. Deep, deep, deep aromas of blackcurrant, blackberry, liquorice, Indian ink, bay leaf, clove and the sweetest of spices. Equally, the palate has a serious side and will certainly benefit from time in the cellar. For now, blackcurrant, blackberry and damson add an autumnal feel against a background of savoury black olive and a little rosemary and fresh sage. The tannins are broad and provide a lovely framework to the fruit. It’s a beautiful wine, calming and cooling. There’s generosity but it’s considered. Thoughtful and reflective winemaking with the power of mother earth on show. Deeply impressive and leaves me feeling reflective. Drink now to 2035. Served using Zalto Bordeaux glassware”.

97+ Points - Magdalena Sienkiewicz "Sampled after three hours of decanting. The perfume is rich and brimming with blackcurrants, blackberries, liquorice and aniseed. Graphite and ink add extra layers of aromatic depth. The palate is tensile and you can easily sense the underlying power of this wine. Very controlled and dignified, all its dark fruit is wrapped in a blanket of textural bliss. I love the savoury edge and balanced freshness which prevails on the expansive palate and broadens as I taste. With 2-3 years in the cellar (at the very least), it should unveil further complexities which will be very exciting to watch. Serious Cabernet which should be treated as such. Sampled in Zalto Bordeaux Glassware."

£29.95 per bottle


Gemtree Wines Cinnabar GSM 2019

96 Points - Stuart McCloskey  “This is a beautiful wine to drink. Seamless, the fruit is ripe and plush, the tannins pillowy with some lift from a judicious line of acidy. I will say that the tannins and acidity provide wonderful shape and support. All-in-all, everything is perfect for a wine of this quality. It reminds me of putting on a cashmere jumper… The fruit leads with raspberry which provides yin & yang of sweetness and acidity. The texture is striking simply due to the silkiness. I detect a sprinkling of dried herbs and earth. Long and balanced to perfection. Drinking fabulously now and will continue to do so until 2025. Decant for an hour or two. Served using Zalto Bordeaux glassware”

£18.50 per bottle


Gemtree Wines Bloodstone Shiraz 2019

96 Points - Stuart McCloskey “How daft of me to sample the most junior wine after the magnificence that is Subterra. Another way of looking at it is – is there breadth and depth to Gemtree’s entire portfolio? In short, the answer is affirmative as this is a joyous beauty strutting with confidence, despite its respectable price tag. The nose offers some warmth from clove and sweet spices. Brooding and actually proving more adult than I expected. The palate is washed with sweet, ripe fruit. Interestingly, this wine lacks the ‘coolness’ of its big brothers, but it misses nothing for it. This is a really joyous slap and tickle of delicious quaffable Shiraz (I have omitted using our Aussie friends’ description, ‘smash-able’). It’s drenched with plums, blueberries, blackberries, mint, vanilla, coconut, kirsch and olive all wrapped in a gentle hug of tannin. The length is super-impressive. In fact (and a little secret) I have a few wines at 25 quid which are not as good! Decant for a few hours and serve using Zalto Bordeaux glassware (this will make all the difference). Drink now to 2025+.”

£18.50 per bottle