D1-VINI Quiz on Harvest to Pressing

Question 1

Grape sorting is often carried out in the winery when creating premium wines to make sure only high quality grapes are used in the production of the wine.
There are certain criteria to be met if grapes are sorted in the winery. Identify the criteria by typing your answer in the box below. Include an explanation on why a winemaker might choose to sort the grapes and the impact grape sorting may have on the final product.

Answer 1

In the winery the main criteria for grape sorting are the grapes need to be intact; hand harvested grapes in smaller bins are preferable to avoid crushing the grapes and releasing too much juice. Once the grapes arrive in the winery sorting can be carried out by hand using a sorting table which can be a conveyor belt, moving table or a static table. Labour needs to be available if sorting tables are used, this is both costly and time consuming.
Optical sorting can be another option, while it does not require so many labour hours, the equipment is very costly.
In general, the cost of the final wine must be a consideration for grape sorting to be carried out. If the grapes are destined for inexpensive bulk wine, they will rarely go through this option.
The reason a winemaker may choose to sort the grapes is to remove MOG and ensure that only healthy, ripe fruit is used which is necessary for high quality wine. Grape sorting is an important process in wine regions where vintage variation is common and the quality of the fruit is affected e.g. Bordeaux.

Question 2

In what circumstances would grape sorting be considered necessary?

Answer 2

In years when the weather is variable during the growing season, achieving full ripeness may be an issue and will increase the likelihood of disease. In cool climate regions, grape sorting may be necessary for all but the most basic quality wines due to greater variability in the weather annually.
Grape sorting is necessary to remove any under ripe and diseased fruit as inclusion in the wine making process will impact the final quality of the wine.
For grapes infected with noble rot, sorting is necessary as the fungus is not uniform and affects individual berries and not whole bunches.

Question 3

There are some instances where grape sorting is not necessary. Give two of these scenarios?

Answer 3

Inexpensive bulk wine producers need to keep the costs down so sorting will not be carried out as this is an expensive practice. Yields are kept to a maximum so no waste is tolerated by sorting fruit.
Years with good weather conditions where the grapes can arrive in near perfect condition will mean grapes don’t have to be thoroughly sorted as there is less chance of under ripe or diseased fruit occurring.

Question 4

Give the reasons why chilling might be used prior to processing the grapes.

Answer 4

To store the grapes before winery equipment (sorting tables, fermentation tanks etc.) becomes available. Often grapes are stored in refrigeration units until equipment is available to use if grapes have to be harvested at a specific time.

The grapes were picked on a particularly warm and sunny day. If grapes arrive to the winery too warm, the rate of oxidation may be increased.

To preserve delicate, fruity aromas. Chilling the grapes will help preserve these aromas.

Question 5

What are positive effects of chilling?

Answer 5

Grapes can be preserved pre-crushing

Oxidation can be lessened

Question 6

What are negative effects of chilling?

Answer 6

Energy costs are expensive
Equipment is expensive
Slows processing the grapes in the winery

Question 7

Are grapes usually destemmed before crushing. True or False?

Answer 7

True

Question 8

Crushing whole bunches of grapes still on the stem helps to increase the chance of oxidation. True or False?

Answer 8

False

Question 9

Whole bunch pressing is more vigorous than crushing destemmed grapes. True or False?

Answer 9

False

Question 10

The juice produced from whole bunch pressing is usually low in solids, tannins and colour. True or False

Answer 10

True

Question 11

What are the positive aspects of whole bunch pressing?

Answer 11

1. Gentle, so a delicate juice can be extracted from the grapes
2. Stems create gaps in the grapes so juice can drain

Question 12

What are the negative aspects of whole bunch pressing?

Answer 12

1. Grapes have to be hand-harvested
2. Lower juice yield than destemmed fruit
3. Lower volume as bunches take up more space in the press

Question 13

Which of the following wines is most likely to have undergone hand-harvesting and whole bunch pressing?

1. Alsace Gewürztraminer
2. Grand Cru Chassange-Montrachet
3. Pinot Grigio from north-east Italy

Answer 13

2. Grand Cru Chassange-Montrachet

The grapes for Premium Chardonnays from Burgundy will be hand harvested and are generally pressed as whole bunches. The sorting process for these wines will also be a lot more rigorous than inexpensive wines.

Question 14

How is the winemaking process called when the grape solids are separated from the grape juice?

Answer 14

Pressing

Question 15

How is the winemaking process called is when pressure is applied to grapes so the skins are broken and juice is released?

Answer 15

Crushing

Question 16

What are the risks typically associated with crushing grapes?

Answer 16

The extraction of bitter or astringent flavours. If the grapes are crushed too firmly, bitter flavours can be released from the skins and pips.

Unwanted oxidation of the juice. Crushing the grapes exposes the juice to oxygen, which can alter the aromas and flavours of the juice.

The extraction of unwanted colour from skins. If black grapes are being used to make white wines, crushing the skins can release some pigment.

Question 17

All white wines go through skin contact as part of the production process. True or false?

Answer 17

False

Question 18

Most white wines are made without skin contact. In the box below, type at least three reasons why skin contact may be avoided.

Answer 18

1. Skin contact can make a wine taste more bitter
2. Skin contact can make a wine taste more coarse
3. Wines that are intended to be delicate or fruity won’t benefit from skin contact due to potential bitterness and astringency
4. If the wine is being produced for early drinking, the tannins extracted during skin contact won’t have a chance to soften
5. The grapes need to be ripe, under-ripe fruit can make a wine taste more bitter and astringent when it undergoes skin contact
6. Higher chance of unwanted oxidation
7. The logistics of including skin contact slows up processing and increases labour costs in the winery.

Question 19

What are typical grape varieties better suited to skin contact?

Answer 19

Gewürztraminer
Muscat
Riesling
Viognier

Question 20

What are typical grape varieties least suited to skin contact?

Answer 20

Pinot Gris
Trebbiano (???)
Cortese

Question 21

Some wines made from white grapes are fermented on their skins, without temperature control or sulphur dioxide additions, and may undergo post-fermentation maceration. What name is often attributed to these wines?

Answer 21

Orange wines

Orange wines do not taste like typical white wines; they are made from white grape varieties using red winemaking techniques. They are usually dry, have notable levels of tannins, and taste mainly of tertiary characteristics such as nuts and dried fruits.

Question 22

The free run juice is lower in acidity and sugar than the press juice. True or false?

Answer 22

False

Question 23

Which style of press would be most appropriate for producing light, aromatic styles of white wine?

Answer 23

Pneumatic press

Pneumatic presses are easier to protect against oxygen so more suitable for aromatic and light styles of white wines. Basket presses are not as easy to protect from oxygen as the juice runs freely through the gaps in the press and collects in a tray.