WSET DIPLOMA D1 CHAPTER 3 EXAM 180
QUESTIONS & CORRECT ANSWERS LATEST 2025
What is the main source of both heat and sunlight? - ANSWER-Solar radiation
What temperature ensures the dormancy of vines - ANSWER-Under 10C / 50F
What temperature can cause winter freeze and damage vines? - ANSWER--20C / -
4F
What factors can stimulate budburst? - ANSWER-Temperatures above 10C / 50F
Warm soil temperatures
What is the optimal temperature for shoot growth and leaf development? -
ANSWER-18-33C / 64-91F
What temperatures promote successful flowering? - ANSWER-Above 17C / 63F
What temperatures promote successful fruit set - ANSWER-26-32C / 79-90F
What is the impact of cold, damp conditions? - ANSWER-Problems for flowering
and fruit set reducing yield and quality
,How does temperature impact grape ripening - ANSWER-Sugar accumulation is
faster at warmer temperatures
Malic acid degradation increases at warm temperature
Formation of aroma precursors and compounds
Color
Tannins
How does current year temperatures impact the following year - ANSWER-Warm
temperatures promote bud fruitfulness next year
How does temperature accelerate sugar accumulation? - ANSWER-Optimal rates
of photosynthesis
Increased grape transpiration moving sugar to grapes
What temperatures impact malic acid degradation - ANSWER-Mean temps > 21C /
70F can lead to rapid acid loss
Mean temps <15C / 59F can reduce acid loss
What impact does temperature have on aroma precursors and compounds? -
ANSWER-Warmer climates = riper aromas/flavors
Cooler climates = hinder breakdown of Methoxypyrazines
What is the optimal temperature for anthocyanin synthesis - ANSWER-15-25C /
59-77F
, Extreme heat and dry condition can negatively impact what vine process? -
ANSWER-Photosynthesis can slow or stop, slowing vine growth and grape
ripening
Why does heat impact photosynthesis - ANSWER-Heat sensitivity of enzymes that
catalyse photosynthesis
Why does water stress impact photosynthesis? - ANSWER-Shutting of stomata
prevent water loss. Closed stomata limit intake of CO2
At what level of sunlight is photosynthesis negatively impacted? - ANSWER-Below
1/3 of full sunshine
What positive impact does sunshine have on grapes (8)? - ANSWER-Development
of anthocyanins in black grapes
Reduction of methoxypyrazines
Accumulation of tannins pre-verasion
Tannin polymerisation after versasion
Increased levels of aroma precursors and compounds
Warms grapes which increases rate of malic acid drop
Successful fruit set
Bud fruitfulness for next year's growth
What negative impact does sunshine have on grapes? - ANSWER-Prolonged
sunshine + hot temps = sunburn
QUESTIONS & CORRECT ANSWERS LATEST 2025
What is the main source of both heat and sunlight? - ANSWER-Solar radiation
What temperature ensures the dormancy of vines - ANSWER-Under 10C / 50F
What temperature can cause winter freeze and damage vines? - ANSWER--20C / -
4F
What factors can stimulate budburst? - ANSWER-Temperatures above 10C / 50F
Warm soil temperatures
What is the optimal temperature for shoot growth and leaf development? -
ANSWER-18-33C / 64-91F
What temperatures promote successful flowering? - ANSWER-Above 17C / 63F
What temperatures promote successful fruit set - ANSWER-26-32C / 79-90F
What is the impact of cold, damp conditions? - ANSWER-Problems for flowering
and fruit set reducing yield and quality
,How does temperature impact grape ripening - ANSWER-Sugar accumulation is
faster at warmer temperatures
Malic acid degradation increases at warm temperature
Formation of aroma precursors and compounds
Color
Tannins
How does current year temperatures impact the following year - ANSWER-Warm
temperatures promote bud fruitfulness next year
How does temperature accelerate sugar accumulation? - ANSWER-Optimal rates
of photosynthesis
Increased grape transpiration moving sugar to grapes
What temperatures impact malic acid degradation - ANSWER-Mean temps > 21C /
70F can lead to rapid acid loss
Mean temps <15C / 59F can reduce acid loss
What impact does temperature have on aroma precursors and compounds? -
ANSWER-Warmer climates = riper aromas/flavors
Cooler climates = hinder breakdown of Methoxypyrazines
What is the optimal temperature for anthocyanin synthesis - ANSWER-15-25C /
59-77F
, Extreme heat and dry condition can negatively impact what vine process? -
ANSWER-Photosynthesis can slow or stop, slowing vine growth and grape
ripening
Why does heat impact photosynthesis - ANSWER-Heat sensitivity of enzymes that
catalyse photosynthesis
Why does water stress impact photosynthesis? - ANSWER-Shutting of stomata
prevent water loss. Closed stomata limit intake of CO2
At what level of sunlight is photosynthesis negatively impacted? - ANSWER-Below
1/3 of full sunshine
What positive impact does sunshine have on grapes (8)? - ANSWER-Development
of anthocyanins in black grapes
Reduction of methoxypyrazines
Accumulation of tannins pre-verasion
Tannin polymerisation after versasion
Increased levels of aroma precursors and compounds
Warms grapes which increases rate of malic acid drop
Successful fruit set
Bud fruitfulness for next year's growth
What negative impact does sunshine have on grapes? - ANSWER-Prolonged
sunshine + hot temps = sunburn
