While most humans see our species (uniquely) as the center of the Earth, many ancient Indigenous peoples, campesinos, and today's scientists know better. There are more organisms (fungi and bacteria) in one tablespoon of healthy soil than there are people on earth.
Humans evolved from bacteria. Our bodies contain an estimated 30- 100 trillion bacterial cells-- a number which dwarfs the number of human cells. We are, essentially, walking bacteria, with equally massive quantities of... air.
The community of microbes in a specific host, or ecological system, is called the “microbiome.” A growing interest in the fascinating study of microbial ecologies, in our bodies, soil, forests, oceans, and man-made environments, is driven by the increasing awareness of how profoundly critical such research is to our understanding of the health (micro and macro) of life on Earth. While the association of microbiome with health is strengthening with new research, the identity of the myriad of specific microbes, and the mechanisms of how they interact with their hosts, is largely a mystery.
The human microbiome is now seen as a wellspring of human health, affecting everything from immunity, metabolism, internal body-clock rhythm, and temperament. Only a few years ago, the National Institute of Health launched the “Human Microbiome Project.” Not only is there a specific microbiome associated with the human species, but every person has a unique “microbiome fingerprint” that contributes materially to what makes you – you.
Research has indicated that the human microbiome varies with geography, climate, season, diet, and is so intertwined with us that astoundingly, the internal clocks of bacteria sync with the clocks of their hosts -- us.
Years ago as I became familiar with the general direction and implications of this exciting work, I quickly realized that the microbiome was the likely key to understanding the true connection between soil and “terroir”, and completing the link between vigneron and wine. Thus, “Taste the Life Within” became the visible tagline to Justice Grace Vineyards, and the inspiration for everything I do in this craft.
In agriculture, there has long been research into the relationship between plants and microbes. Important functions provided by microbes include disease resistance, nutrition availability, metabolism, hormone stimulation, root health, and ecosystem development. As a result, the biotech industry has provided many inoculants for use for a variety of Ag purposes.
But new research is leading to a broadening in our understanding of the plant-microbe interface and relationship. While it seems most attention is focused on the root-soil interface, evidence suggests the “phyllosphere” (the leaf-air interface covering an estimated 250 million square miles on Earth) contains a massive microbiome which greatly affects the immediate host and the health of the planet.
In short, recent new technology tools are accelerating our understanding of both the microbiome itself, and the fundamental roles it plays in critical aspects of all life.
Microbiome & the wine industry
The term “terroir” is both saint and sinner. Ideally, it gives expression to a somewhat vague conception of how a specific vineyard or AVA expresses itself – consistently -- in wine. In reality, for decades it has been marketed, by wineries worldwide and the trade, to explain everything from wine faults, to the widespread use of wine additives and modern winemaking processing equipment, to effects which are simply dominant winemaker footprints. The word has lost so much meaning from its misuse and overuse, that tellingly, UC Davis viticulture professor M.Matthews published “Terroir and Other Myths of Winegrowing” in 2016.
Since I began learning about winemaking in the 1990's, I have seen “terroir” applied to the contribution of specific forests used in oak cooperage (which later was disavowed by same coopers), the secondary/ tertiary character of highly acclaimed old-world wines (which suddenly disappeared when better winery hygiene practices emerged), and distinct modern-era wines even when it is apparent the stylistic footprint of the winemaker completely overwhelms any subtle vineyard expression.
Owners of vineyards worldwide have used “terroir” to attempt to establish the incomparability of their valuable land. A unique AVA (warm days/ cool-nights preserving acidity, anyone?) and vineyard site/soil logically the place to start. But in this modern era of winemaking, with the overwhelming % of wine by volume made with the help of non-vineyard additives, and machines which dial in precise wine chemistry determined by a high ratings formula dataset – what could “terroir” possibly mean for the wines made from those same sites?
It is disingenuous, frustrating, and a great disservice to consumers when the media enables this across the globe by not insisting on transparency from grape to glass.
Even in an ideal situation, where these wineries were non-interventionist, there has never been much science clearly demonstrating the direct connection between AVA, soil, and wine character. It is ironic that many who accept the use of “terroir” for premium estate wines, readily dismiss the biodynamic movement because of the perceived lack of science behind it. We have had only observations and assumptions attempting to explain both.
Since 2010, as my focus shifted dramatically to natural wines, my efforts became dedicated to allowing the life within the vineyard, winery, and barrels to express itself. Not driven by dogma, but by my own evolution having walked the vineyards, immersed my hands in countless musts, and tasted the difference in single wine lots across neutral barrels, since 1999. You can immediately see – and feel-- the difference when you walk vineyards with soils gray and devoid of life. You can see-- and feel – the difference in musts allowed to proceed in their own way, vs. wines driven by expediency and certainty.
Around that same time, gene sequencing tools were becoming more widespread and enabled research focused on identifying the diversity of organisms involved in wine fermentations and in vineyards.
Instinctively, I believe that the microbiome within the 1) vineyard, 2) winery, and 3) winemaker is the primary enabler of true “terroir.” Initially, this Life emanates from a unique vineyard site, but then melds with the microbiome shared across the winery and winemaker interface, to create a “microbiome co-op”.
I assume it is just like the wisdom of indigenous peoples, campesinos, fermentation practitioners for millenia, and other farmers who have dedicated themselves to living in harmony with the microbial and other life around them. It wasn't concrete science, but observation and instinct that shaped their efforts.
In wine, my curiosity strikes a desire to understand the precise mechanisms which might consistently produce appealing molecules inherent in my wines. But, just as I have long ago stopped getting musts lab tested for brix or anything else, I don't actually want to know how to gain this mechanical precision. That is contrary to my ethos of allowing the Life Within to express itself, with each vintage and variation, on its own. I want distinction, not uniformity. My intent is to work alongside whatever that year's unique microbiome is-- across all interfaces – and only intervene when there is risk of “faults” overwhelming the natural expression that is forming by itself.
Despite the risk and loss of control, it is deeply satisfying as a winemaker to simply work under the assumption that there is a more diverse, healthier microbial ecosystem in a vineyard/ wine with less toxic inputs, and the resulting wine will be more vibrant, complex, distinct, and pure.
The role of Soil in “terroir”: a dramatic new perspective
Consensus views of soil's possible pathway to wine expression, are via water moderation, root zone depth, pH effects, and perhaps mineral balance/deficiency. What if all of those things are true – but Not in the way commonly perceived for so long to justify “terroir”? Rather, they are all necessary factors creating a unique microbial ecosystem for that site. This is the main catalyst for molecules derived from precursors (perhaps unique to a vineyard site) present in the must, and resulting from the miracle of fermentation.
It would follow naturally that land farmed with less toxic inputs would harbor greater microbial life.
Deborah Parker Wong, recently cited biochemist P.Cifuentes, in SOMM Journal 12 '17/1 '18:
“...there's a distinct kingdom of organisms found only in soils farmed sustainably with organic fertilizers.”
See also “The effects of organic and conventional management practices on feeding activity of soil organisms in vineyards”, by AJ Reinecke, et al, African Zoology, 2008
“This indicated that the organic treatment favoured soil biological activity directly or indirectly.”
See “The Vineyard Yeast Microbiome, a Mixed Model Microbial Map” Setati, et al, PLOS Journal, Sept 2013
“...the least treated vineyard displayed significantly higher species richness, including many yeasts...”
Research also indicates that while some species are common across varietals planted worldwide, there are distinct regional microbiomes:
See “Microbial biogeography of wine grapes is conditioned by cultivar, vintage, and climate”, by UC Davis viticulture professor Bokulich, et al, 2013
“We demonstrate that grape-associated microbial biogeography is nonrandomly associated with regional, varietal, and climatic factors across multiscale viticultural zones. This poses a paradigm shift in our understanding of food and agricultural systems beyond grape and wine production...”
Working with winemaker Greg Allen at Far Niente, UC Davis viticulture professors conducted a fascinating exploration of regional microbiomes:
See “Associations among Wine Grape Microbiome, Metabolome, and Fermentation Behavior Suggest Microbial Contribution to Regional Wine Characteristics”, by Bokulich, et al 2016
“Through a longitudinal survey of over 200 commercial wine fermentations, we demonstrate that both grape microbiota and wine metabolite profiles distinguish viticultural area designations and individual vineyards within Napa and Sonoma Counties, California. Associations among wine microbiota and fermentation characteristics suggest new links between microbiota, fermentation performance, and wine properties. “
Fermentation as Living Wine Co-Op
As grapes are received at the winery, the winery microbiome, and that of the winemaker, joyfully unite with the microbiome on the grapes, in the co-operative process of fermentation.
Just as each human has a unique “microbiome fingerprint,” (i.e the winemaker's unique physical ingredient in wine) the “microbiome co-op” enables the possibility of a unique expression from each site. The mechanisms of how the Life Within produce signature effects from the raw material of a vineyard, or how long they might survive during the conditions of fermentation, or aging in lees, is largely unknown. But isn't that the same level of uncertainty that did nothing to stop the wine industry worldwide from using soil as the primary explanation of “terroir” prior to recent tools and research?
“Terroir” is ascertained through comparisons. In an ideal situation, the vineyard microbiome alone might create a unique expression from the vineyard, farmed consistently, and with wine made in the same winery, with the same winemaker, year after year.
But the last element – that of the approach of the winemaker – can easily overwhelm anything that might have come before it. Decisions from additives (including inoculating with 3rd party yeast/ bacteria), temperature, SO2/ copper sulphate/ lysozyme, etc, paint-by-number winemaking, oak barrel regime, and much more, all have potential to dwarf any unique expressions form the microbiome co-op.
It follows that natural winemakers have, theoretically, the greatest opportunity to maximize the expression of the microbiome co-op, because on the whole, this approach would do the absolute least to modify the Life Within, and elements of the must. The Life Within is empowered to do what it wishes, on its own
Since I began this journey of exploration in the 1990's, I can't recall a more exciting time than recent movement to natural wines, and the new gene sequencing technology enabling greater understanding of a farming and winemaking ethos that has been derided by so many for so long.
Consumers can use this information as support to help align their purchasing decisions to their beliefs. But the help of the Wine Trade is needed to empower them. Let's hope this evolving track in microbial ecology is not as readily dismissed as Biodynamic® farming or natural winemaking has been.
In Biodynamics®, the application of minute quantities of preparations has been cast aside by many in the trade-- but at a microbial level, many of the preparations are directly related to creating, nurturing, and disseminating massive quantities of life, with well known physiological benefits to plants. As we trade one unknown for another, instinct has its place.
For me, it's in the bottle.