[Information based on DipWSET D1 material]
Rootstocks. Not all vines are planted on rootstocks, but the vast majority of them are. While the original reason for using rootstocks was to prevent agains phylloxera, today there’s a wide range of rootstocks that can influence vine—and grape—characteristics. As mentioned in Dealing with Pests, most rootstocks are hybrids, today bred to take advantage of some useful qualities of both parent species.
[Information based on DipWSET D1 material]
I covered details in a few of these stages in previous posts (Please see Flowering and Fruit set, and Ripening.), but as I approach my exam in just a few days, I realize it may be helpful to have a consolidated list that covers each stage of a vine’s growth cycle to put those other posts into a broader perspective. Hence, the impetus for this post.
[Information based on DipWSET D1 material]
Before getting started, make sure to check out my post on Flowering and Fruit Set.
A Brief Overview:
Ripening is the third stage of Grape Development. Starting from the top…
During grape berry formation—the first stage of Grape Development— malic and tartaric acids begin to accumulate, aroma compounds and precursors begin to form (also check out Aromatic Compounds post), tannins start to accumulate. But the grapes themselves are green and quite bitter—very little sugar has accumulated at this point.
Another interesting anecdote is that water flow is quite high during grape berry formation, but too much water and nitrogen (please also see Stuck Fermentation to learn about soil nutrients) can prolong this phase, as it will encourage green growth, not grape growth. So “mild” water stress is the way to go here.
Veraison is considered second stage of Grape Development. This is when grapes begin to change their color, skins become more supple, stretchy. But regarding the grape growth, it actually slows down. This phase is what many viticulturists refer to as a “lag phase.”
Now we can enter the third stage—ripening.
[Information based on DipWSET D1 material]
In our last exciting episode of WSET studying, we discovered the world of soil and left off acknowledging that there are loads of tests that growers can conduct before a vineyard is established to understand the composition and overall health of his/her/their potential vineyard. Just as important are regularly scheduled tests—think of it as your vineyard’s annual checkup. Soil health tests can indicate what, if anything, needs to be improved—be it the structure, nutrient level, water availability, or pest management.
First, let’s define what soil actually is. Soil is the upper layer of the earth and is made up of geological sediment. Sediment is another word for weathered bedrock—aka solid rock. Soil also includes organic remains in the form of humus as well the water and air found in the pores/space between the sediment. That’s…a lot of stuff. But wait. There’s more…
[Information based on DipWSET D1 material]