Chapter 9: Harvest

Question 1

Explain how it is determined when grapes are ripe

Answer 1

• Sugar Levels - amount of sugar measured by handheld refractometer (brix)
• Acidity levels
• Aroma and tannin ripeness (determined by taste w/ experience)
• High tech means (visible or near infrared spectroscopy) - gives multiple readings for sugar, acidity and various other compounds and measures
• Tasting grapes still one of most important ways of deciding when. To harvest

Question 2

What method is used to calculate acid levels?

Answer 2

A titration

Question 3

Identify the brix level at harvest for dry still wines

Answer 3

Between 19-25 brix, which converts to 11-15% abv

Question 4

Identify the harvest dates for Loire (Chenin Blanc)

Answer 4

Over a period of 4-6 weeks according to style

Early - sparkling
Mid - dry and off-dry
Late - botrytis or late harvest

Question 5

Identify the harvest dates for California (Zinfnadel)

Answer 5

Early to mid-August - White Zin

Sept - Red wine

In hot area, because of uneven ripening, have to determine whether to include shriveled grapes

Question 6

Identify harvest dates for wines with residual sugar

Answer 6

Harvest late to concentrate sugars in the grapes

Botrytized wines often need hand harvesting over several passes through the vineyard

Eiswein or Icewine picked only when temps below -8ºC (18ºF) for Canadian Icewines

Question 7

Explain why some critics believe hang time is detrimental

Answer 7

Some believe detrimental because overly alcoholic and unbalanced wine lacking in natural acidity and having extra-ripe fruit characters, but some critics and consumers enjoy

Question 8

Identify the two harvesting options

Answer 8

Machine Harvested
Hand Harvested (preferred and required)

Question 9

Identify who defaults to machine harvesting

Answer 9

Inexpensive to mid-priced wine and for larger-scale production

Esp when vineyard designed to be machine harvested - even row spacing, turning space at the end of rows, flat land or land with small, regular gradient

Question 10

Identify the exception to the rule that inexpensive to mid-priced wine and for larger-scale production uses machine harvesting

Answer 10

S. Africa because low cost labor

Question 11

Explain how machine harvesting has improved quality of reputation

Answer 11

• Select out undesirable fruit by hand before harvesting by machine
• Use a bow-rod shaking maching (rather than older machines that beat the vines) - gentler and can be set to be more selective
• Invest in very latest machines with optical sorting devices that can crush grapes and add SOX2 to limit oxidation
• Rigorous sorting upon arrival, including removal of MOG and unripe and rotten grapes

Question 12

Define ‘MOG’

Answer 12

Matter other than grapes

Question 13

Identify the advantages of machine harvesting

Answer 13

1. Faster and substantially cheaper in large vineyards (if designed for machines; 1/3 price of hand harvesting)
2. Avoids issue of lack of availability and unreliability of casual workers
3. Harvest at night be kept up to 15ºC (59ºF) cooler and therefore in better condition, reduced microbial spoilage and oxidation
4. Timing of harvest can wait until desired level of ripeness and then carried out quickly
5. Starting white winemaking with cool fruit preserves the intensity of fruit aromas and helps to save on cost of refrigeration

Question 14

Explain how machine harvesting can save costs w/r/t white, fruity wines

Answer 14

Starting the winemaking with cool fruit preserves freshness of fruit aromas and helps to save cost of refrigeration

Question 15

Identify the disadvantages of machine harvesting

Answer 15

1. Less gentle than hand harvesting
2. If whole bunches required, cannot use
3. If wishing to avoid oxidation or extraction of phenolic compounds (delicate white wines)
4. Rental or ownership is not cost effective for small vineyards
5. Unsuitable for growers that have several different varieties ripening at different times in same plot
6. Not suitable for steep slopes or vineyards with limited access
7. Need skilled operator because quality of work dependent on that skill
8. Competition for rental of machine at best moment of harvest if machine not owned
9. Purchasing harvester is major investment

Question 16

Explain why hand harvesting might be preferred

Answer 16

Aiming to make premium wines and prefer hand harvesting to remove whole grape bunches from the vines by cutting the stem of each bunch

Question 17

Identify the advantages of hand harvesting

Answer 17

• Highly selective at a bunch-by-bunch level and remove any diseased or under- or extra-ripe fruit at point of harvest
• Can deal with steeper slopes, irregular rows, and mixed planting in same vineyard
• If handled with care and put in small, stackable crates, minimize crushing of grapes and release of juice which would make juice prone to oxidation and microbial spoilage

Question 18

Identify the max weight of small, stackable crates used for hand harvesting

Answer 18

10-15 kilos

Question 19

Identify the disadvantages for hand harvesting

Answer 19

1. More expensive in medium to large vineyards
2. Reliable work force not always available
3. Need to train and supervise workforce
4. More easily carried out during the day where may not be able to avoid high temperatures, raising chance grapes will be spoiled by microbes or oxidation (can do at night with lights)

Question 20

Identify an example of hand harvesting preferred

Answer 20

France and Italy - cooperatives receive fruit from small-scale growers and use the fruit for large batches of wine (in expensive, high volume)

Question 21

Identify when hard harvesting is required

Answer 21

Premium sparkling wine where whole bunches required for whole bunch pressing

Beaujolais and other wines that will be made by carbonic or semi-carbonic maceration which require whole bunches

Harvesting only botrytis affected bunches (Trockenbeerenauslese Riesling in Mosel)

Steep slopes (Douro Valley) or uneven land

Bush vines because not on a trellis - too much damage to plants and grapes without trellis

Question 22

Harvest generally marks the end of:
Ripening
Véraison
Dormancy

Answer 22

Ripening

Question 23

As a general rule, grapes typically ripen __ days after the beginning of flowering.

Answer 23

100 days

Question 24

What is ‘potential alcohol?

Answer 24

The amount of alcohol that would be created by fermenting all the sugar in grape must into alcohol,

Question 25

In cool regions, when potential alcohol of __% - __% has been reached, grapes can be harvested.

Answer 25

9.5%-11% ## Footnote AOC Petit Chablis requires min 9.5%; Chablis requires 10%, and Bourgogne Blanc requires 10.5%

Question 26

Deciding when to harvest has shifted from just potential alcohol to include considering what other data points?

Answer 26

* Has the regional climate warmed? (easier to ripen grapes in cooler regions now) * Better viticulture: enabling the vine to fully ripen grapes * Focusing on aromas, flavors, and tannin ripeness that is now considered as or more important that optimum surgar ripeness because it's easier to adjust sugar, acid, and alcohol than deal with unripe tannins, underripe, herbaceous aromas and flavors.

Question 27

If rain looms right around a grape grower's pick date, what are the consequences of picking too soon? Or too late, after the rain?

Answer 27

Too soon: risk picking under-ripe fruit Too late: risk diluting juice; risk grapes splitting from bloating, which can lead to rot or crop loss

Question 28

Most dry still wines are harvested between _º and _º Briz

Answer 28

19º and 25º Brix

Question 29

Grapes harvested between 19º and 25º Brix will convert into _-_% abv.

Answer 29

11-15% abv

Question 30

One of the most important ways a grape grower decides when to harvest is:

Answer 30

Tasting the grapes

Question 31

When establishing a vineyard that will be machine harvested, what are some of the design details necessary ot accommodate machinery?

Answer 31

* Even row spacing * A turning space at the end of rows * Planted on flat land or land with a small, regular gradient

Question 32

Machine-harvesting has been associated with lower-quality wines in the past. What are some ways that grape growers are trying to improve wine quality?

Answer 32

* Dropping undesirable fruit by hand prior to harvesting by machine * Using a bow-rod shaking machine (vs. older machines, which beat vines to remove the fruit), which is gentler and can be set to be more selective * Optical sorting devices * Rigorous sorting upon arrival in the winery, including removal of MOG and unripe and rottne grapes