Terroir /terˈwär/ began as the French word to describe the effect of a given agricultural environment on the characteristics of a wine. It is now recognized that terroir affects all foods and it is the effect on the plant of the soil, the climate and perhaps most importantly the microbes and other critters both helpful and antagonistic. Terroir explains why organic food is consistently rated more flavorful. These flavors come from two sources/families of immune induced products; the terpenes/terpenoids and flavonoids that plants make in response to stress and from the metabolites of microbes.
Organic food has more terpenoids and flavonoids because they are not exposed to pesticides, but rely on working with a healthy microbial community to stay healthy. We know that these terpene and flavonoid substances have huge nutritional value, even though they are not listed as nutrients by the U.S. government which claims that organic food has the same nutritional level as conventionally raised produce. These products have anti-inflammatory, anti-fungal, anti-bacterial, anti-viral and anti-cancer properties. Thus, food grown without pesticides not only saves you from the harmful effects of pesticides, but arms you with protection against cancer, pathogens and inflammatory disease.
Now let’s talk about the microbes. The only way to grow crops without harmful pesticides is to allow the plant to grow the microbial population that it needs. The plant grows this population by secreting nutritional substances that lure the microbes it wants to the root area. When attacked by a pathogen on leaves or root, the plant ups the production of terpenes and flavonoids and secretes specific substances that bring in microbes antagonistic to the pathogen (the soil is the origin of all our antibiotics). These microbes as well as the microbial metabolites can enter the plant and produce flavor, e.g. the major terroir effect on wines. This has been identified as a metabolite of a soil fungus that migrates up the phloem of the plant and is found in the grape. How is this terroir? The fungus or strain of fungus that exists in an area is dependent on the soil, the climate and the grape variety.