G’day, ladies and gentlemen. We are going to discuss a particular type of climate, the Mediterranean climate from the blog of “Terroir & vintage”. We are already familiar with “Terroir”, aren’t we? Such kind of climate is infrequent, representing at only 2% of overall identified climate types on the earth, although it is perhaps prevalent among renowned wine regions.
What is Mediterranean climate?
Mediterranean climate refers to a specific area, which is situated the west part of continents between about 30° to 40° latitude with a mild wet winter and a warm or hot, dry summer. Classic regions include Mediterranean Europe, Northern Africa, South Africa, Western and South Australia, California and Chile. This particular type of climate is well-suited for grape-growing, because a “Mediterranean” summer with adequate solar radiation is essential for photosynthesis which is responsible for sugar ripeness and phenolic ripeness.
Compared to variable maritime climate which has annual dissimilarities on wine quality consistency, and relatively short growing season of continental climate, vintage differences are less frequent phenomena in Mediterranean climate. Robinson (2019) and Wine Australia (2020) reveal that the average annual rainfall during growing season in both Bordeaux and Barossa, which are representative for maritime and Mediterranean climate, possess 469 mm and 160 mm respectively. It can be seen that the average annual rainfall of Bordeaux is almost a three-fold number as Barossa average annual rainfall during growing season. Excessive, Unfavourable precipitations may cause potential issues like fungal disease or flavour dilution as vintage variations, see “Terroir & vintage”.
A Potential disadvantage of viticulture in Mediterranean climate regions
First of all, a paradoxical effect on grape ripeness has been acknowledged as a likely drawback by grape-growers in Mediterranean climate regions. Before past decades, viticulturists primarily concentrated on sugar ripeness of grapes which is effortlessly achieved by abundant sunlight and warmth in the particular climate. Unlike balmy, arid climate with plentiful sunshine is absolutely positive for sugar ripeness, phenolic ripeness is less likely to be optimal in such kind of climate. Phenolic ripeness is also known as physiological ripeness of grapes, which includes flavonoids like anthocyanins (colour of red grapes), catechins (bitterness) and polymers (tannin) existed on grape skin, generally refers to astringency, green or stalky aromas and flavours when grape skin is underripe.
As growers has realised the probable issue, it is a tendency for them to seek a proper site with factors of temperature moderating such as proximity to sea with cool ocean current, sea breeze or fogs, undulating terrain with significant diurnal range, high elevations with naturally lower temperature than plains and even viticultural management like Goblet pruning (bush vine training). Almost of all the renowned regions in new-world or Mediterranean Europe benefit from temperature moderating factors. For example, Barossa Valley is moderated by huge day and night temperature differences; Napa Valley in Northern California is tempered by chilly California Current with humidifying morning fogs as a natural shade from scorching Mediterranean sunshine.
As a whole, Mediterranean climate is a blessed unique climate type which is ideal for viticulture although a possible problem exists. Grape growers perhaps have tackled the issue with meticulous research on searching quintessential vineyards.
Discover Australian wine, Wine Australia.
The Mediterranean climate: an overview of the main characteristics and issues, Lionello. P, Malanotte-Rizzoli. P, Boscolo. R, Alpert. P, Artale. V, Li. L and Ulbrich. U.
The Oxford Companion to Wine 4th Edition, Robinson. J and Harding. J.