Harvest dates

Question 1

Define Harvest.

Answer 1

When the grapes are picked. Marks the end of ripening.

Question 2

Traditional harvest date.

Answer 2

100 days after the beginning of flowering

Question 3

Why is potential alcohol less relevant today?

Answer 3

Warmer climate speeding up sugar development

Better viticulture enabling grapes to ripen more successfully

More focus on aroma and tannin development

Question 4

Impact of weather on harvest decision

Answer 4

Untimely rainfall around harvest may force an early harvest to avoid dilution and rot of the grapes.

Question 5

Three ways ripeness is measured.

Answer 5

1. Sugar levels –> Potential alcohol
2. Titratable acidity
3. Tannin and flavour development

Question 6

How is sugar in grapes measured?

Answer 6

Using a refractometer (handheld or digital) Brix , a measure of dissolved solids, is the most common scale

Question 7

How is sugar in grapes measured? (wider version)

Answer 7

The sugar content in grapes is typically measured in terms of Brix, which is a unit of measurement used to quantify the sugar content in a solution. Brix is defined as the percentage of sugar by weight in a solution, with the sugar being dissolved in water.

To measure the sugar content in grapes, a refractometer is used to measure the refractive index of a sample of juice from the grapes. The refractive index of the juice is proportional to the sugar content, so by measuring the refractive index, the sugar content can be determined. The Brix value can then be used to determine the sugar concentration of the grapes.

Question 8

Typical sugar level range for dry wine

Answer 8

19-25 Brix (equivalent of 11-15% ABV )

Question 9

Method for calculating acidity.

Answer 9

Titration or pH meter

Question 10

How to detect flavour and aroma ripeness in the grapes?

Answer 10

Tasting is the most common method. High tech analysis can be used but is expensive.

Question 11

Importance of harvest date for wines that have residual sugar?

Answer 11

• Some harvested late to concentrate the sugars in the grapes
• Some need hand-harvesting over several passes through the vineyard to select the most botrytised grapes at that time
• Some grapes can only be picked when temperatures reach below certain levels (Icewine, Eiswein)

Question 12

What is extended hang-time? Why is it controversial?

Answer 12

The amount of time grapes are left on the vine after ripening. - Con: Overly alcoholic and unbalanced wines lacking in natural acidity and having extra-ripe fruit character. - Pro: Critics reward these wines with high scores; consumers like them