Wset3 // Winemaking

Front 1

What role does the pulp of the grape play in winemaking?

Back 1

The pulp’s largest single component is water, second is sugar, which will be used by yeast to make alcohol.

Wine’s two most abundant acids are also in the pulp - Tartaric Acid and Malic Acid.

Front 2

Explain Protective or Anaerobic Winemaking and why this style may be used.

Back 2

Anaerobic Winemaking involves making every effort to keep grapes and juice away from oxygen before they are used for winemaking by filling winery equipment with either carbon dioxide or nitrogen.

This style of winemaking can be used to make wines that a winemaker wants to be dominated by primary fruit.

Grapes may also be picked at night since chemical reactions occur more slowly at lower temperatures.

Front 3

Describe Aerobic Maturation and why a winemaker would use this technique.

Back 3

Aerobic Maturation involves ageing wines in wooden vessels that are normally made of oak. These vessels are watertight, but not airtight so small amounts of oxygen can make its way through the oak to interact with the wine.

Front 4

Describe a Barrique.

Back 4

A Barrique is a 225-litre oak barrel. These have a greater oxidative effect than larger vessels as they present a proportionately larger surface area of wood to wine. Wine is rarely kept in a Barrique longer than two years.

Front 5

How is oxygen used in production of fortified wines?

Back 5

For styles such as Oloroso Sherry, Tawny Port, and Rutherford Muscat, extra oxygen contact is created by not completely filling the vessel and can last for many years in order to achieve pronounced tertiary characters of caramel, toffee, and nuts.

Front 6

What role does sulfur dioxide play in wine making?

Back 6

Antioxidant- SO2 protects grape juice and wine from effects of oxidation.

Antiseptic - SO2 is toxic to many strains of yeast and bacteria that can cause unwanted flavours in a wine.

Front 7

What influences can oak maturation have on a wine?

Back 7

Oak fermentation or ageing may be used to add depth and complexity.

Oxidative - Allowing a wine to develop tertiary aromas like leather or earth.

Tannin - Giving a wine more structure, textural complexity.

Aromas - Giving a wine aromas and flavours such as toast, vanilla, smoke, and cloves.

Front 8

List and describe the key stages of Grape Processing.

Back 8

Grape Reception: Received and usually dosed with SO2.

Destemming and Crushing: Breaks the skins and liberated free run juice, but avoid crushing seeds.

Pressing: Separates liquid and solid constituents of the grape. For Whites, this happens before fermentation For Reds, this happens after fermentation.

Front 9

Define Must and Must Weight.

Back 9

Must = Grape Juice

Must Weight = Level of sugar in juice

Front 10

Explain RCGM.

Back 10

Rectified Concentrated Grape Must (a colourless, odourless syrupy liquid) may be added before or during fermentation to increase the fermentable sugars in a wine and raise the level of alcohol in the final wine.

Front 11

Explain Chaptilisation.

Back 11

Chaltilisation is an alternative form of enrichment where sugar from a source other than grapes, such as sugar beet, is added.

Front 12

Most common yeast strain used for wine fermentation?

Back 12

Saccharomyces cerevisiae

Front 13

List the ways to stop alcoholic fermentation.

Back 13

All sugar consumed.

Yeast run out of nutrients other than sugar.

High sugar and alcohol combo can stop the yeast.

Killing/removing yeast by adding SO2 or grape spirit.

Front 14

List two ways a winemaker can control fermentation.

Back 14

Yeast - Winemaker can use wild yeast strains found on the grape bloom or add cultured yeast to the must.

Temperature - Controlling temperature can influence the flavours of the wine being made. Lower temps preserve floral aromas and encourage development of fruity flavours in white wines. Higher temperatures extract better colour and tannins from grape skins.

Front 15

Describe MLF.

Back 15

Malolactic Fermenation takes place once the alcoholic fermentation has finished. Lactic acid bacteria is added to convert the tart malic acid (found in apples) to the softer lactic acids (found in milk).

MLF softens and reduces acidity, and creates buttery flavours.

Front 16

Describe the two different types of lees produced through fermentation.

Back 16

Gross Lees is the dead yeast cells that are heavy enough to fall to the bottom of the vessel in a matter of hours.

Fine Lees are smaller and they settle more slowly. Winemakers may choose to keep white wine in contact with fine lees to add extra flavours and a richer texture.

Front 17

Explain why Blending plays such a vital role in the winemaking process.

Back 17

Balance - Ex) Free run wine may be blended with press wine to increase tannins in final product.

Consistency - Variation among bottles of the same label will be viewed as a daily. Oak influence, fruit variation, and harvesting items are all factors that can create inconsistencies.

Style - Variations across vintages may occur, many winemakers aim to produce their wines in a certain house style.

Front 18

Describe Racking.

Back 18

After fermentation, once the gross lees have settled in a deposit, the wine can then be slowly pumped into a different vessel leaving the sediment behind.

Front 19

List and describe the three techniques used to achieve Clarification.

Back 19

Sedimentation: Gross Lees settles in a deposit and wine is gently pumped into another vessel leaving the sediment behind. Can be expedited using a centrifuge.

Fining: Some wine constituents clump together over time. Fining expedites this process by adding a “fining agent” to the wine that bonds with certain constituents allowing them to be removed.

Filtration: Physically removes particles by passing wine through a filter.

Front 20

List the areas that require Stabilisation.

Back 20

Tartrate Stability - Clear or purple crystals called tartrates can form in wine. Cool temperatures will accelerate the formation of these crystals and chilling a wine down below 0 degrees C for a short period can allow these to be removed.

Microbiological Stability - Yeast and bacteria can spoil a wine and make it undrinkable. This can be avoided by a number of factors: MLF, Sterile Filtration, adding an appropriate amount of SO2.

Oxygen Stability - Minimized by avoiding oxygen exposure and ensuring SO2 is topped up.

Front 21

Explain Maceration.

Back 21

After crush, grapes may be left to macerate for a period at low temperature before fermentation to extract colour and flavour compounds. Referred to as cold maceration or cold soaking. Tannins not readily extracted at this point as they are more soluble in alcohol.

Front 22

What qualities will a wine have when made with a grape variety that is slow ripening?

Back 22

Concentrated fruit flavours balanced by high acidity.