Microclimates. Wine lovers have probably heard the term many times. At first glance it appears fairly self-explanatory. It’s just a tiny little area’s temperature, right? Yes, it does describe the temperature of a relatively small terrestrial area – very small, actually! But what we typically think of as microclimates in scientific viticulture aren’t precisely that. Scratching deeper into this subject exposes a treasure of information. When you understand the distinctions, they can help you choose which wineries to visit when seeking specific varietals you enjoy.
How small is the “micro” in “microclimate?” According to the Texas Cooperative Vineyard Site Assessment Extension, the broadest weather and temperature patterns of a region are called macroclimates, generally referring to an area 100 to 1000 square miles or more. The actual location or site of a particular vineyard is termed the mesoclimate, and is affected by a location’s landscape and topographical features. A mesoclimate’s influence is measured in feet: hundreds to thousands horizontally, and only tens of feet in elevation. Mesoclimate concerns mostly elevation, slope, and drainage.
What’s left is microclimate. This includes the soil up to the vine canopy. Like a rainforest canopy, a vine canopy comprises all the visible parts of the grape plant. The art of managing a vine canopy is an entire science beyond this article’s scope. Suffice it to say that if you taste a superb wine, the vineyard manager is likely masterful at canopy management—and root management, as well!
What we are calling microclimate comprises aspects of both macro- and mesoclimate, because so much contributes to the 1500+ varietal tastes encountered in California alone. Temperature, elevation, soil condition, water and drainage all affect wines’ flavor development.
According to Virginie Boone’s Napa Valley & Sonoma: Heart of the California Wine Country (Northland Publishing, 2003), ideal conditions are: 30° – 50° latitude north and south, average temperature at least 50°F, and 100 sunny days during the growth period from June to September. The good news is that most of these conditions exist in the world’s great wine areas. So next time we’ll look at the more precise conditions that affect wine, and how vintners manage them.
While I love to throw the word “terroir” around, I am just beginning to learn about grape growing and vineyard management. If you have some tidbits to share, I would love to hear from you.