TERROIR is a French word, as in TERRITORY. Originally applied to wine, but later it was seen to be equally relevant to essential oils and Tea, or any phyto-pharmaceutical crop. Terroir is a factor of MICRO-ENVIRONMENT (soil, shade, latitude, longitude, wind direction, water, rain and territory or terrain).
Terroir can be defined as an interactive cultivated ecosystem, in a given place, including climate, soil and the effect of the micro-environment on sensory attributes of the end product. Because terroir involves many factors, related to both the plant and the physical environment, terroir must be studied by a pluri-disciplinairy approach.
Essential Oils are VOLATILE FRACTION, extracted by STEAM DISTILLATION of HERBS/PLANT MATERIAL. It could be flowers, as in Rose, leaves as in Cymbopogons, seed as in Celery, rhizome, as in Ginger, roots, as in Vetiver, or the whole plant, as in mints/geranium.
The main identifier is the BOTANICAL SPECIES, on basis of which the CAS nomenclature is based.
However, it has further been noticed that an essential oil of SAME botanical species, but of different origins have different oil profiles. It has been seen that a location, and thus the micro-climate has a bearing on the “Fragrant Notes” of an essential oil.
Variation in quality, as a function of TERRITORY or a Phenotype, WITHIN a GENOTYPE is one of the mystiques and mysteries of essential oils.
GENOTYPE/PHENOTYPE – Within the same GENUS, there could be numerous phenotypes, each producing a unique essential oil. Clonal Selections are made on basis of various DESIRABLE BENCHMARKS. For example, cornmint (MENTHA ARVENSIS) in India has about 5 different clones and there are over a dozen different selections of Basil.
TERRITORY or Location- also called the TERROIR EFFECT- The impact of geographical and environmental factors on the quality of essential oil, has not been well documented. It has been known to exist, and wisdom has been passed on by word of mouth. Old timers would look up the JANTRI ( the weather predictions based on the lunar/solar calendar, much like the astrological charts), as well as THE ACTUAL CONDITIONS in the field, before planning the harvest.
In MINTS- MENTHA ARVENSIS, which is one of the essential oil crops grown extensively in our area- it has been seen to YIELD HIGHER ( quantity as well as quality) when harvested on a WESTERLY WIND, whereas GERANIUM MAXIMISES ON AN EASTERLY !!!!
Likewise, every crop has some very unique requirements. In some crops, the effect is more pronounced than others….
I have read about the MISTRAL WINDS, IN FRANCE- during the month of MAY. This has some bearing on the quality of ROSE OIL being grown/distilled in the FRENCH ALPS !!!
The percentage of the MAJOR INGREDIENT, may or may not change so significantly, as that of some of the minor ingredients- BUT- invariably there is a change in the AROMA PROFILE.
In connection with lemongrass, I have made a few observations over the last 25 years.
Dr Wendy Maddocks Jennings has written an article on this TERROIR effect in the International Journal of Professional and Holistic Aromatherapy- which gets published in the upcoming edition ( APRIL- JUNE quarter 2020)