Grape Reception

Question 1

What are the four main operations of processing when grapes arrive at the winery?

Answer 1

1. chilling
2. sorting
3. destemming
4. crushing

Question 2

What options are there for moving grapes around the winery?

Answer 2

large volumes: conveyor belt or screw conveyor

small volumes: manually with pallet truck or forklift

Question 3

Why might a winemaker choose to chill grapes?

Answer 3

To decrease the rate of oxidation and spoilage organisms

Question 4

How might a winemaker keep the grapes cool?

Answer 4

1. put them into a refrigeration unit
2. a heat exchanger for machine harvested or crushed grapes
3. add dry ice to the crates of grapes

Question 5

What factors impact the level of grape sorting required in the winery?

Answer 5

1. ripeness of grapes
2. health of grapes
3. intended wine quality and price
4. whether there has been any sorting in the vineyard
5. the physical state of the grapes (crushed, machine harvested)

Question 6

Why does more grape sorting lead to more cost?

Answer 6

• labor costs
• time required
• reduced yield

Question 7

What is MOG?

Answer 7

Material Other than Grapes (leaves, twigs, insects)

Question 8

Why may cool climate grapes require more sorting?

Answer 8

Higher levels of disease and unripe grapes

Question 9

What are the options for sorting grapes for quality wines?

Answer 9

1. removal of unwanted grapes and bunches during picking
2. sorting by hand at the winery
3. optical sorting using a high tech digital imagine equipment, only used for premium and super premium wines

Question 10

How do destemmers work?

Answer 10

A series of blades within a rotating drum removes grapes from the stems

Question 11

Which types of wine might utilize destemming upon reception of the grapes?

Answer 11

Most white wines and many red wines

Question 12

Why might winemakers destem the grapes?

Answer 12

Stems contain tannins, which can be extracted if the stems are left in contact with the wine.

Tannins are undesirable in white wines, and extra tannins may be undesirable in red wines.

Question 13

Why may winemakers choose not to destem the grapes?

Answer 13

1. red wine fermentations using whole bunches
2. carbonic maceration
3. whole bunch pressing for some white wines

Question 14

Define grape crushing.

Answer 14

Application of pressure to the grapes to break the skins and release the juice.

Question 15

How was crushing performed traditionally?

Answer 15

By foot

Question 16

What is must?

Answer 16

The mixture of grape juice, pulp, skins, and seeds resulting from crushing.

For white wines, this can refer to the grape juice being fermented.