Saturday, March 12, 2016

Thermal Amplitude

Funny how we get sidetracked while researching blog subjects.  We began with an investigation of Piattelli Vineyards 2013 Premium Reserve Malbec, number forty-four on the Wine Spectator's 2015 Top 100 list.  Having a couple cases of that one in the store, we found their story to be moderately interesting and their website to be exceptional compared to others but we found their location in the Lujon de Cuyo appellation in western Mendoza to be of greater interest.  Then we stumbled upon the term "thermal amplitude" and really got an education as to why Mendoza Malbecs are so good.

The Lujon de Cuyo appellation in the upper Mendoza valley in western Mendoza was Argentina's first legislated wine appellation (1993) and today boasts many hundred year old vineyards. Argentina's long (by new world standards) wine production history began with immigrants from southern Europe in the early 1800's.  Cuyo is the historic name for Mendoza and it hosted many of those early wine making immigrants.  In 1830 one thousand hectares there were in vines.  By 1910 vineyards numbered forty-five thousand hectares.  Clearly a nineteenth century wine boom was happening in Argentina.

The conditions in Mendoza that were so inviting to immigrants included rocky alluvial soils (sand over clay) in a semi-arid, continental climate desert - at a thousand feet elevation!  Worldwide, a thousand feet is usually the elevation where grapevines cease to grow but our intrepid pioneers planted their euro-vines and Malbec quickly ascended to the head of the class.  Today two-thirds of all Argentine plantings are Malbec.

Our Piattelli Lujon de Cuyo Malbec vineyards lie at a 3,152 foot elevation!  Benefits at that level include increased intense sunlight and automatic organic certification since no pests live at that elevation. Other radical differences from Europe include the flat lands of Mendoza which only rise gradually in altitude, the furthest thing from European hillside vineyards.  As these elevations increase, the soil becomes more granular and less fertile from organic matter forcing the vine to struggle for its existence while the temperatures become colder at an average of one degree per one hundred feet of elevation.  Pure irrigation water is amply available from the melting snows further up the Andes.

Here's where we'll turn things over to for an understanding of thermal amplitude.  "During photosynthesis in daytime, carbohydrates are taken into the vine's reserve organs including the grapes, themselves.  At night respiration takes place without photosynthesis consuming some of the carbohydrates.  A lower temperature (at night) means a greater thermal amplitude and a lower amount of components consumed during respiration. This results in a more intense grape expression with a richness of components that affect color, aroma, and palate structure."

When we think of tannins in wine we think of the burning quality in the mouth from young wine.  Actually tannins may be monomeric or polymeric, having one or more dimensions, and the high altitude intensely sunlit Mendoza vineyards decidedly yield the latter.  Malbec grape skins there are thick and heavy with tannins while the wines still end up being soft and round.

Our recent Cousino-Macul blogpost now gains relevance in light of this foray.  Maipo Chile is just over the Andes from Mendoza.  Their incredible Cabernets mirror in a very different way what Argentina does with Malbec.

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