Quiz - Harvest to Pressing Flashcards
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.
Identify the criteria for performing grape sorting.
include an explanation on why a winemaker might choose to sort the grapes and the impact grape sorting may have on the final product.
- 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. Labor 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 labor 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.
In what circumstances would grape sorting be considered necessary?
- 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.
In which instances is grape sorting not necessary?
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.
What are the reasons why chilling might be used prior to processing the grape?
- To store the grapes before winery equipment (sorting tables, fermentation tanks etc.) becomes available.
- The grapes were picked on a particularly warm and sunny day.
- To preserve delicate, fruity aromas.
What are the positive and negative aspects of grape chilling?
Positive:
1. Oxidation can be lessened
2. Grapes can be preserved pre-crushing
Negative:
1. Equipment is expensive
2. Energy costs are expensive
3. Slows processing the grapes in the winery.
What are the major destemming / crushing options?
- Grapes are usually destemmed before crushing.
- Crushing whole bunches of grapes still on the stem helps to decrease the chance of oxidation.
- Whole bunch pressing is gentler than crushing destemmed grapes; the juice produced is usually low in solids, tannins and color.
Which aspects of whole bunch pressing are positive and which ones are negative?
Positive:
1. Gentle so a delicate juice can be extracted from the grapes
2. Stems create gaps in the grapes so juice can drain
Negative:
1. Lower volume per press cycle as bunches take up more space in the press
2. Grapes have to be hand-harvested
3. Less juice than destemmed fruit
Destemming has an impact on the aromas/flavors of the final wine along with the rate and efficiency of processing the juice. Stalks may give the wine a slightly bitter or astringent quality if vigorously pressed. However, the extra room stalks create in the press aid drainage for the juice. The juice produced has lower phenolic compounds and more delicate flavors as the skins have not been broken prior to pressing. Whole bunch slows down processing as less quantities of fruit can fit in the press compared with destemmed and crushed fruit.
Cost factors have to be taken into account and the impact on the potential wine style when deciding to destem or not, prior to pressing.
Describe crushing and pressing
Pressing is when the grape solids are separated from the grape juice.
Crushing is when pressure is applied to grapes so the skins are broken and juice is released.
What are the risks typically associated with crushing grapes?
- Unwanted oxidation of the juice.
- The extraction of unwanted color from skins.
- The extraction of bitter or astringent flavors.
True or false? All white wines go through skin contact as part of the production process.
False
Most white wines are made without skin contact. What are the main reasons why skin contact may be avoided?
- Skin contact can make a wine taste more bitter and coarse.
- Wines that are intended to be delicate or fruity won’t benefit from skin contact due to potential bitterness and astringency.
- If the wine is being produced for early drinking, the tannins extracted during skin contact won’t have a chance to soften
- The grapes need to be ripe, under-ripe fruit can make a wine taste more bitter and astringent when it undergoes skin contact
- Higher chance of unwanted oxidation
- The logistics of including skin contact slows down processing and increases labor costs in the winery.
Most white wines are made without skin contact. What are the main reasons why skin contact may be avoided?
Better suited to skin contact: aromatic grapes, such as:
1. Gewurztraminer
2. Muscat
3. Pinot Gris
4. Riesling
5. Sauvignon Blanc
6. Viognier
Less suited to skin contact:
1. Cortese
2. Trebbiano
Skin contact maximizes flavor extraction and therefore it is most effectively used on aromatic grape varieties that have lots of aroma compounds that can be extracted, such as Riesling, Gewurztraminer, Viognier, Muscat and Sauvignon Blanc. In these aromatic varieties that are seldom matured in oak, it is also a way of enhancing texture. However, there are some winemakers that feel that the technique leads to homogenization, reducing the variations between grape varieties and different vineyard sites.
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?
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.
True or False: The free run juice is lower in acidity and sugar than the press juice
False
At the start the press juice will be similar to the free-run juice, but as the pressing continues, and more pressure is applied, more solids, tannin and color are extracted. The press juice also has lower acidity and less sugar than the free run juice, and typically makes wines that are fuller bodied (compared to those from the free run juice).
Which style of press would be most appropriate for producing light, aromatic styles of white wine? Think about the risks of oxidation.
Pneumatic press
