The Roll of Immunity in Complex Wines
The word “terroir” has no direct translation from French to English and is sometimes thought to refer simply to the place in which a crop was grown. It is, however, a more in-depth term referring to all environmental influences on the crop. Soil content and climate are obvious factors, but the subtlety of a season's weather patterns, pest and disease pressures, and a farm’s management style can all greatly affect a terroir. Join us in an exploration of how Sustainable agriculture impacts terroir and yields more flavorful foods and drink.
As a vineyard, we focus wine grapes and subsequent wine, but the ideas to follow and the term “terroir” itself can be used to understand many other crops and products. We will discuss how a plant's immune system leads to more complex flavors and how sustainable farming supports plant health and self-reliance resulting in higher levels of compounds that contribute to flavor.
First, let’s introduce “metabolites.” The primary metabolites of a plant or animal are responsible for major bodily functions: growth, reproduction, and development. The Secondary Metabolites (SMs) are more specialized and evolve in response to environmental stimuli. In wine, SMs are key to flavor, texture and aromatics. They are predominantly phenolic compounds such as flavonoids, anthocyanins and tannins. SMs generated in grapes also influence SMs that the yeast themselves produce during fermentation, all combining to create the unique and complex qualities of a finished wine.
Imagine a grapevine living in a perfectly sterile environment. It has soil, water, sunlight, and carbon dioxide. Its primary metabolites impart what it needs to live and produce fruit, but in the absence of other environmental stimuli the plant’s flavor profile will be lacking. Thankfully, nature is far from sterile and external stimuli are abundant so when a common grapevine pathogen such as powdery mildew is introduced, the plant is challenged to build defenses against it. SMs are part of the plant’s solution to pathogens. This flood of chemical compounds contributes significantly to a plant’s immune system. It is in this context that we look at how farming methods play a role.
In conventional farming, heavy doses of fungicides might be rushed in when a disease such as powdery mildew is first detected. This will rid the vineyard of the blight; however the individual plants have little chance to build their own immunity, keeping SM levels low. With a sustainable approach, the plant is challenged to become more resilient to pathogens and pests by producing greater quantities of SMs.
As sustainable farmers, we strive to encourage plants to overcome disease and fight pest pressure through the production of their own natural defenses. We will apply relatively low rates of organic/sustainable sprays when the situation calls for it, but our first approach is to watch and wait and let the vines build SMs. Another sustainable practice is the cultivation of companion plants, both native “weeds” and herbal allies that also help bolster the vines’ immunity. These plants help build soil vitality that we carefully monitor throughout the year. Annual composting and fertilizing, along with foliar applications of micronutrients and minerals ensure the vines have the resources they need to manufacture SMs.
Although the degree varies from farm to farm, it is now widely accepted scientific knowledge that organically and sustainably grown foods will always have higher levels of SMs. And as previously mentioned SMs are the very building blocks of flavor. While our goal is to farm in a way that improves and preserves the land for future generations, we revel in the fact that it also produces better wines for today.
For more complex, dynamic, and flavorful wines, choose sustainable.