White and Sweet Winemaking Flashcards
Skin Contact
Generally, for white wines the juice spends little time in contact with the skins in order to reduce the risk of oxidation. For some aromatic varieties, the winemaker may choose to keep the juice in contact with the skins for a short period to increase flavor and texture.
Clarify of the Juice
Freshly pressed grape juice contains fragments of pulp and grape skins and therefore needs to clarified before fermentation can begin. This can be done using the same techniques used to clarify wine before bottling (settling, centrifugation, fining and filtration) Some winemakers choose to leave a small amount of fragments in the juice, making the wine less susceptible to oxidation (and can add richness and flavor complexity).
Fermentation Temperature + Vessel
For white wine fermentation, 12-22 degrees C. Fermentation at too low a temperature can fail to capture varietal fruit characteristics. At higher temps, risk is that varietal fruit chars. will be lost. When stainless steel vessels are used temp. control mechanisms are applied to prevent temps from running too high. White wine can also be fermented in barrels but it is harder to control fermentation temps, generally run warmer.
Blending
Helps a winemaker improve consistency, enhance the balance of the wine, and create a certain style.
What is one of the common adjustments made to high-volume, inexpensive wines during the winemaking process?
Acidification; Chardonnay in particular can be flat and flabby when acid levels are too low.
Winemaking: Simple Mass White Wine
- before fermentation juice will be highly clarified to ensure fruity flavors are retained during fermentation; settling using gravity will take too long, therefore the winey may use a centrifuge or filter to speed up the process.
- Stainless steel tanks are the fermentation vessel of choice. Fermenting at cool temps to preserve primary fruit aromas.
- Commercial yeasts will be used for quick, reliable fermentation.
- If a winemaker wants to retain acidity, MLF will be prevented by chilling the wine and adding SO2. the wine will also be racked off its lees as soon as fermentation has finished and stored temporarily in another inert vessel.
- Barrel aging is expensive so oak chips or staves may be added to provide toasty aromas if required.
- many of these wines contain some residual sugar. more often the case for Chardonnay–often the wines will be fermented dry and then sugar, in the form of unfermented grape juice or RCGM will be added.
- These wines are typically stabilized, fined and sterile fermented.
White Winemaking: Premium | Aromatic
Goal of the winemaker for aromatic varietals is to retain and enhance the primary fruit character and aromatic potential of these grapes in the final wine.
Sauvignon Blanc | Winemaking Style
SB is highly aromatic with high acidity. Early ripening, well suited to cool climates where the temperatures help to retain the varietal’s refreshing character. Loire Valley, France and Marlborough, New Zealand are most famous regions. SB from Sancerre and Pouilly Fume show elegance and restraint. Cool climate gives aromas of green apple and asparagus, with a hint of wet pebbles. Marlborough is similarly cool but more intense sunlight gives wine with very vibrant flavors. The wines display powerful aromas of gooseberry, elderflower, grapefruit and passion fruit. In most cases SB is best drunk young.
Pessac-Leognan in Bordeaux is an instance where the winemaker takes an approach more common with non-aromatic varieties. The wine is fermented and matured in at least a proportion of oak giving a rounder body to the wine and spicy toasty notes. SB is also blended with Semillon here to add body and richness to the wine.
Riesling | Winemaking Style
Very tolerant of cold winters and buds late so avoids spring frosts, making it suitable for cold climates. In these climates it produces wine with green fruit flavors and often floral notes. In warmer climates it becomes richer in flavor, with more citrus and stone fruit, but arguably loses some delicacy. Riesling is mid-to-late ripening depending on the style of the wine being produced; left on the wine is can accumulate sugar w/o losing its naturally high acidity. Also widely used to make botrytised dessert wines.
Riesling is one of the most long-lived white wines; can age for sometimes decades in the bottle. When mature, can develop flavors of honey and toast, but still retain acidity.
Sweet Winemaking | Stopping the Fermentation
Fortification (addition of grape spirit) is the traditional way to stop fermentation while sugar is still present. This kills the yeast and no further fermentation is possible. Ferm can also be stopped with a high dose of SO2 or by chilling the fermenting wine. This wine must be filtered to remove any remaining yeast.
Sweet Winemaking | Adding a sweetening component
In some countries, like Germany, medium-sweet wines can be created by the addition of unfermented grape juice or Sussreserve. RCGM can also be used for mass wines.
Noble Rot (sweet winemaking)
Used for the very best sweet wines, Sauternes, Tokaji, and Beerenauslesen and Trockenberenauslesen. Caused by the fungus botrytis cinerea. Grapes must be fully ripe before the development of the rot. Second, the grapes must be grown in a region with humid misty mornings followed by sunny dry afternoons. Damp conditions in the morning allow rot to develop; warm sunny afternoons slow the development of the rot and cause water to evaporate from the grape, concentrating its acids, flavors, and sugars. Wines made from grapes with noble rot have a distinctive honey, apricot, citrus zest and dried fruit aromas. Several pickings by hands are usually necessary as the spread of noble rot is never uniform.
Drying grapes on the vine | sweet winemaking
Often referred to as passerillage. once grapes reach full sugar ripeness they begin to dehydrate and turn to raisins on the vine, increasing the sugar concentration in the juice. These wines have an overripe character (dried fruit) and richly textured mouthful. Wines made this way are sometimes labelled at Late Harvest.
Drying grapes after picking | sweet winemaking
Causes healthy harvested grapes to dehydrate, concentrating the sugar in the juice. Conditions must be dry and warm for this to be successful, and care must be taken to remove any rotten grapes or the rot will spread. Technique is used in passito wines of Italy such as Recioto della Valpolicella DOCG. Wines have a raisiny quality.
Freezing grapes on the vine | sweet winemaking
Healthy grapes are left hanging on the vine into the winter months. When freezing temps arrive, the water in the grape pulp turns into ice. When the grapes are picked and pressed, this ice remains in the press and the sugar content of the resulting juice is increased. This technique is used to produce Eiswein in Germany and Icewine in Canada.
