General Flashcards
Why cool climate is suitable as grape growing environment for Sparkling wine ?
Cool climate where grapes struggle to ripen are ideal for sparkling wines. The grapes are just-ripe in flavour, but retain the acidity required for high-quality sparkling wines. Sugar accumulates slowly, giving still, base wines with low alcohol (around 9-11% abv). This is necessary because the second fermentation used in many methods of making sparkling wine produces and additional 1-2% abv.
Grapes for sparkling wine therefore tend to be grown in regions that are at greater latitudes, such as Champagne, England, Tasmania. Or that have cooling influences, such as those near to the coast (Sonoma) or at high altitude (Trentodoc).
In warmer areas, the grapes tend to have riper fruit flavours and lower acidity compared to grapes grown in cooler site. This may be desired for short-aged wines (e.g. those made by tank method or with short time on the lees in transfer/traditional method), as the fruit will provide the only or dominant flavours. However, to make elegant, balanced, long-lees-aged sparkling wines less intense fruit flavours are usually preferable.
What are the characteristics and roles of Chardonnay in Sparkling wine production ?
This variety is well suited to the production of autolytic notes of sparkling wines. These wines are noted for their aromas that include brioche and/or biscuit (graham cracker).
Chardonnay’s subtle apple and citrus aromas and flavours compliment rather than compete with the aromas from yeast autolysis.
Its early ripening of fruit flavours is an asset in cool conditions and it also retains the high levels of acidity and low levels of alcohol needed in sparkling wines while avoiding under-ripe flavours. Thus it brings apple and citrus flavours and high acidity to the blend.
However, being early budding, it is vulnerable to spring frosts. It is also prone to coulure and millerandage. It has more disease resistance than Pinot Noir, but it is susceptible to powdery mildew, grapevine yellows and to botrytis bunch rot in wet periods before harvest.
Yields can be high in the best years without loss of quality, making this an attractive option for growers.
What are the characteristics and roles of Pinot Noir in Sparkling wine production ?
This variety is also an early budding and early ripening variety like Chardonnay, and is therefore suited to a cool climate. Being an early budding also makes it prone to spring frosts.
The yields are more moderate than Chardonnay and the quality drops if the yield is too high.
It is prone to Coulure. It is thin skinned and more disease prone (Downy Mildew especially, Powdery Mildew, Botrytis Bunch Rot, Fan Lean and Leaf Roll).
It lends body to the blend.
What factors within the grape variety that can influence the style of the wine ?
- Intensity of aromas (aromatic or neutral grape variety)
- Ability to retain acidity while ripening
- How the base wine responds to autolysis where applicable, for example, Chardonnay becomes creamy, whereas Xarel-lo becomes toasty and smoky.
Why harvesting for Sparkling wines occurs earlier than for Still Wine production ?
In order to achieve the high acid, low alcohol profile desired for sparkling wine.
Early picking also means that the grapes are less likely still to be on the vine as rainy autumn weather starts, reducing risk of fungal disease.
Compare the advantage and disadvantages of hand harvest to machine harvest in Sparkling wine production ?
Hand harvesting permits sorting and collecting in post-harvest selection to exclude disease-infected grapes. Hand picking and collecting in small crates minimise the splitting and crushing of the grapes, as well as the subsequent oxidation of this juice along with extraction of phenolics (including colour and tannin).
However, hand harvesting is slow, labour-intensive and can be expensive.
The advantages of Machine harvesting are that is faster, so for large estates the grapes are more likely to all be picked at the desired point of ripeness, and it is cheaper. It also permits night-time harvesting, thus delivering cooler grapes. This is an advantage because oxidation is slowed down, resulting in fresher wines. Diseases or damaged grapes can be removed by hand just prior to machine harvest, allowing a degree of selection.
However this does increase costs. Machine harvest can rupture the skin of the grapes, resulting in phenolic extraction and oxidation.
Explain the pressing for Sparkling wine
Whole-bunch pressing is often practised for premium traditional method sparkling wines. This is one of the gentlest forms of pressing, providing a delicate juice that is low in solids and phenolics (including tannins and the anthocyanins that provide colour). The stems also helps to create a network of channels through which the juice can flow easily, minimising the pressure required.
However, fewer bunches can be loaded into the press at any one time compared to crushed grapes, and therefore this process is more time consuming.
Pressing should be performed as quickly and gently as possible, especially for the black skinned grape varieties, minimising maceration with and extraction from the skins, which would bring unwanted colour and tannins. These phenolic compounds can make the wine taste bitter and feel coarse on the palate.
Both pneumatic and basket presses are commonly used, due to their ability to press very gently. It is common to split the juice into different press fractions. The different press fractions can make useful blending options. The juice from press fractions is higher in phenolics, solids and PH than the free run juice. Wines made from press juice tend to be faster maturing, and therefore this fraction can be useful in wines with a short maturation that are made for immediate consumption.
Why the buttery flavour found on white wines that have undergone malolactic conversion are not typically found on Sparkling wines ?
This is because diacetyl, which gives the buttery notes, is metabolised by the yeast during the second fermentation.
