How can vineyard practices minimize the need for must adjustments in the winery? (2024, Q1) Flashcards
Introduction
What is the primary aim of vineyard practices regarding must composition?
To produce grapes with balanced sugar, acid, and phenolic levels to reduce the need for corrective winery interventions.
Introduction
What types of must adjustments are commonly made in the winery?
Adjustments to sugar (chaptalization, dilution), acid (acidification, deacidification), and phenolics (tannin or enzyme additions).
Canopy Management and Microclimate
How can dense canopies in cool climates affect grape composition?
They reduce sunlight exposure, leading to low sugar accumulation and high acidity, increasing the need for deacidification.
Canopy Management and Microclimate
What canopy strategies improve sunlight penetration in cooler climates?
Moderate leaf removal and careful shoot positioning.
Canopy Management and Microclimate
How does sunlight exposure impact phenolic development in red grapes?
It enhances anthocyanin and tannin synthesis, reducing the need for tannin additions in the winery.
Canopy Management and Microclimate
What happens if red grapes in hot climates are overexposed to sunlight?
Acids can degrade and phenolic compounds can be damaged, leading to possible acid and tannin corrections.
Canopy Management and Microclimate
What canopy strategies are used in hot climates to avoid grape damage?
Minimal leaf removal, optimal shoot positioning, and shade netting.
Canopy Management and Microclimate
about shade netting in warm climates?
It lowers sugar accumulation, preserves acidity, and delays ripening, reducing the need for acidification or dilution.
Irrigation and Water Stress Management
How does excessive water stress near harvest affect grape composition?
It causes berry dehydration, sugar concentration, and acid loss—potentially requiring acidification or dilution.
Irrigation and Water Stress Management
How does moderate irrigation help with must balance?
It prevents shriveling and stabilizes sugar and acid levels.
Irrigation and Water Stress Management
about late-season irrigation?
It prevents dehydration without diluting must, supporting natural sugar-acid balance.
Irrigation and Water Stress Management
What is the “Goldilocks principle” of irrigation?
Providing just enough water to avoid stress, without stimulating new vegetative growth.
Irrigation and Water Stress Management
How did late-season irrigation in California improve grape composition (Previtali et al., 2021)?
It delayed harvest, improved phenolic ripeness, and reduced sugar, lowering the need for dilution or acidification.
Irrigation and Water Stress Management
What techniques help manage excess water in wet or poorly-drained vineyards?
Installing drainage systems, planting cover crops, and increasing vine density.
Crop Load and Vine Balance
How does high crop load influence sugar and acid in grapes?
It slows sugar accumulation and retains more acid, sometimes requiring chaptalization.
Crop Load and Vine Balance
What are the risks of low yields in warm climates?
Overly rapid ripening, acid loss, and underdeveloped tannins—potentially requiring tannin additions.
Crop Load and Vine Balance
Why is it important to match crop load to vine capacity?
To allow for balanced ripening of sugar, acid, and phenolics.
Crop Load and Vine Balance
What did Carmona-Jiménez et al. (2021) find about cluster thinning in Tempranillo?
Moderate thinning at véraison improved sugar and phenolic content, enhancing balance.
Crop Load and Vine Balance
What role does the timing of crop thinning play?
Early thinning is more effective; late or excessive thinning can lead to over-ripeness.
Soil and Nutrient Management
Why are soil and petiole analyses important in viticulture?
They help detect nutrient deficiencies or excesses that could impair ripening and lead to must adjustments.
Soil and Nutrient Management
How can iron deficiency affect grape ripening?
It causes chlorosis and reduces photosynthesis, potentially delaying ripening and requiring chaptalization or deacidification.
Soil and Nutrient Management
What is the impact of nitrogen deficiency on grape quality?
It limits vegetative growth and fermentation capacity, possibly leading to underripe fruit.
Soil and Nutrient Management
How does excess nitrogen affect grape must?
It encourages excessive vigor, dilutes berry compounds, and raises must pH—possibly necessitating acidification.
Harvest Timing
Why does harvest timing influence the need for must adjustments?
Because late picking raises sugar and reduces acid, while early picking can yield underripe fruit—both leading to possible corrections.
