The Location, The Climate & The Weather…

Location

Depending on where you are on the globe, the climate is the most fundamental in determining the suitable spot to cultivate wine-making grapes.  How many degrees will the vineyard be from the Equator? How far will the vineyard be to the ocean or other significant body of water?  Will the vineyard be in the mountains? On a sloping mountain-side and at what altitude?

Vinifera grapes grow best in a few very small pockets on a few continents in roughly two bands around the planet: between 30° to 50° North and the same South of the equator. Geographically, the valleys of the western Rocky Mountains are in a similar latitude as Bordeau, France. Though these two places do not have the same climate, many aspects crucial to the production of wine grapes are very similar.

Climate

There are three types of ‘climates’ that affect the quality of the grape. All three of these climate types can be identified in the image at the top of this page…

Macro-climate is the general pattern of any given region: Oceans and seas, prevailing winds, mountains, and other major topography all determine the basic climate.

Meso-climate refers to the conditions at any particular vineyard and how it differs from its neighbors. The slope of the land, the cast of the sun and the distance from moderating influences are all grouped in this category.

Micro-climate is the climate within the canopy of the vine itself.  This can vary from row to row, plant to plant and even cluster to cluster.

Macro would be the hazy mountains in the far background and how they help manifest the clouds and rain; Meso is in evidence by the gentle sloping of the land from the right foreground down to the center and gently up to the mid-ground; Micro can be noted by the rows closest to the trees- the shade from the tree once its leaves grown will influence the fruit on the vines closets to it.

Weather

For the 100 growing days in Grape Season, the weather conditions play a huge role in the quality of the fruit.

In winter, the vines and roots are dormant. If the temperature drops too much below -20°C, the water in the plant cells expands too much and ruptures the membrane. The vine will die.

Springtime and the sap starts to flow in the vines when the temperature averages around 6°C. The canes rejuvenate, new growth happens and the vine canopy develops. Once the leaves reach a certain point – sufficient to shade the delicate bunches of fruit, the pollinated blossoms drop off and the nubs of new grapes start growing…

Warm sunshine and moderate humidity allow grapes to grow evenly with resilient skins and firm flesh. This leads to a balance of acidity and sweetness within the fruit .  Weather dangers for grapes are the same for any crop. Frost, hail and strong winds are particularly damaging during flowering.

In Autumn, excessive rain will cause rot of the heavy fruit during harvesting. Too much heat during harvest will cause the grapes to dehydrate – rapidly drawing off the acidity. Too much sun late in the season will cause the leaves and curlers to suck the life from the fruit clusters – muting the grapes’ sweetness.

In Winter, some of the best grapes are shrouded and protected from predators and reserved for Ice Wine! We’ll explore Ice Wine later.

The Dirt, The Plant & The Fruit

Dirt

All plants draw their nourishment from the soil in which they are planted. Growth of healthy canes and even root distribution are determined by the type of soil vis a vis the supply of nutrients the roots receive and the supply of water to the vine. Ideally, a vineyard’s deep subsoil should have decent water retention to keep the layer of topsoil moist.

Dirt is dirt! What’s the difference? Glacial Till is dirt that was bulldozed and scoured from the granite bedrock and left behind during the IceAge. This term also refers to the dirt and silts that filtered out of the ice as the glaciers receded.  Clay Loam and Sandy Loam are found near bodies of water. The porous soils drain to the lowest impermeable barrier ie) a lake. The sandy soil around rivers and in riverbeds’ ancient floodplains can be fertile! Silty Clay is a type of soil deposited OVER Glacial Till – its often found near escarpments and cliff-y geography. eg) Southern Italy and Niagara Escarpment

If a soil retains heat, it will speed up ripening. Colder soils will slow ripening. Dark, dry soil is warmer than heavy set soils. Soil with too much limestone is more alkaline and produces more acidic fruit. Its very important to match both the grape variety and roots to the predominant growing conditions.

Grapevines & Canopy Management

Everything above the ground is called the Canopy. This includes the main trunk, the canes that grow from the trunk, the shoots, the curlers, and of course the fruit. Things like trellising, pruning and covering are all considered ‘canopy management’.  The grower wants to grow luscious grapes that have the perfect qualities for wine-making, not masses of knotted and tangled vines. So…   Pruning, desuckering, and shoot positioning are very important  in optimizing the nutrients that feed the fruit, not the leaves.  The leaves are important, especially when trellising.  A Trellis, as you can see in the image on the top of the screen, is that series of posts and lines that the ‘curlers’ twine around to keep the plant growing ‘up’, not out. The leaves are trimmed from around the fruit to maintain the optimal micro-climate to prevent diseases and such.

The Fruit

Should the wine maker know his art and selected favorable qualities from all of the above variables AND if he’s matched these variables to the grapes best suited to where he is established, there’s a good chance he’ll produce a good wine.

A wine grape must have the right balance of fruit sugars and acids to produce a palatable wine. I’ve used the term Vitis Vinifera a few times already – this is the classic European wine grape.  Also mentioned in a blog post is The Great Wine Blight which resulted in the mass grafting of parasite-resistant North American rootstock to the vine-stock of France. This slowed the spread of the parasite and improved the overall health of the vines.

We’ve all heard of the various varietals that produce the popular wines and there’s an extensive entry in Wikipedia

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In the next installment of this on-going essay, I’ll explore the more common the grape varietals and their resultant wines, the actual process of wine making, cellaring and aging. Later on, I hope to get into the choosing of wines, wine and food pairing skills and proper ‘tasting’.

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***a formal bibliography will be published when all parts of this essay are complete and posted.  If you’d like references clarified for any statement presented in this dissertation, email thevinoboy@thevinoboy.com

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~tvb