Viticulture / Vineyard Management

Question 1

Generally speaking, explain the relationship between soil pH and wine pH.

Answer 1

Generally, there is an inverse relationship. If the soils pH is high, the end wine’s pH is lower and vice versa.

Question 2

What are 3 ways of preventing/fighting frost?

Answer 2

1. chaufrette / bougies (smudgepots) lit in the vineyard to warm the surrounding area (used in France and Europe)
2. circulating the air with the big wind turbines - brings the warm air that rises back down to the ground (used in Napa)
3. aspersion - spraying the vineyard with water which insulates the buds / vine.

Question 3

How calcium in soils affect the end pH of the wine?

Answer 3

Vines uptake calcium and potassium from the same receptors so the presence of calcium inhibits potassium uptake and results in higher acid (lower pH) wine.

Question 4

What style of pruning / trellising is most common in Napa?

Answer 4

Cordon pruned, vertical shoot positioned trellis.

Question 5

How does St. George rootstock affect yields?

Answer 5

St. George is good at resisting drought, but results in lower yields.