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WSET Diploma > Unit 2 - Vinification > Flashcards

Unit 2 - Vinification Flashcards

1
Q

EU definition of “wine”?

A

the product obtained exclusively from the total or partial alcoholic fermentation of fresh grapes, whether or not
crushed, or of grape must

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2
Q

Grape maturity?

A

One of the most decisive factors in determining wine quality and style
Physiological changes - phenolics & taste
Biochemical changes - sugars & acids

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3
Q

Key questions for harvesting?

A

When
Forecasting
Preparing
How (manual vs machine)

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4
Q

Harvest date?

A

Grape ripeness

  • sugar
  • acid
  • health
  • phenolic ripeness

Agrochemicals (fungicides, insecticides, herbicides, pesticides, etc)
- withholding period
- fermentation and health problems
e.g. sulphur –> hydrogen sulphide
copper –> brown haze, toxic copper salts in wine

Weather

  • rain –> dilution, grape swelling and bursting
  • hail

Availability of resources (human and mechanical)
Legal restrictions

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5
Q

Havesting - Getting ready?

A

Estimating the crop (sufficient tank space)
Checking & cleaning equipment and machinery
Tanks clean and ready for use
Oenological products (yeasts, sulphur, enzymes, etc)

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6
Q

Havesting - Machine vs Hand Factors to consider?

A

Factors to consider

  • quality
  • speed
  • economics
  • feasibility
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7
Q

Machine Harvesting Pros and Cons?

A

Machine

  • speed, grapes at peak; cheaper labour costs; cool night
  • damage, oxidation, no selection, cost of machinery, flat land, trellis system (no bush nor pergolas)
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8
Q

Hand Harvesting Pros and Cons?

A

Manual
- less damage, more selectivity, slopes, less $ for equipment
- high labour costs (10X machine), slower
- for sparkling wine, carbonic maceration (whole bunches); Tokaji, Beerenauslese, Trockenbeerenauslese
(selection of grapes); required by law

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9
Q

Havesting - Transport & Reception?

A 
Use shallow picking containers
Less transfer between containers
Less dumping heights
Refrigerated trucks
Minimize delay before processing

Oxidation

  • browning, loss of aroma
  • CO2/nitrogen blanket; potassium metabisulphite; harvest at night; min delay

Microbial growth
- eliminate rotten grapes; clean equipment; berry integrity; min delay

Contamination

  • rain
  • leaves & stalks
  • MOG (material other than grape)
  • soil
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10
Q

Key questions for grape processing?

A 
Sorting
De-stemming
Crushing
Type of press
Amount of SO2
Must treatments
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11
Q

Sorting in French?

A

Triage

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12
Q

De-stemming?

A

Tannin control and ease of processing
Egrappoir = de-stemming machine
Most grapes are de-stemmed
Not for sparkling wines and carbonic maceration
Not required for machine harvested grapes

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13
Q

De-stemming Pros?

A

Pros

  • prevent release of phenolics, herbaceous flavours, MOG
  • more efficient pressing
  • remove water and potassium (absorb colour and alcohol)
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14
Q

De-stemming Cons?

A

Cons

  • whites: slower pressing and drainage (not for fine wines)
  • reds: compaction of pomace cap; tannins and colour
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15
Q

Crushing?

A

Release free-run juice
Reduce the solid parts of the grape to the correct condition for fermentation and maceration
Increase extraction of tannin and colour
Careful not to damage grape seeds
Not to crush for semi-carbonic maceration (Spain, Beaujolais, Languedoc-Roussillon for Carignan
and Grenache)

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16
Q

Fouloir?

A

crusher

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17
Q

Crushing Equipment?

A

Equipment

  • foot or de-stem/crush
  • heat exchanger
  • SO2 to reduce oxidation and prevent microbial spoilage
  • use of pectolytic enzymes to release more juice
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18
Q

Pressing?

A

Use of minimum pressure
Done at grape reception for whites; after fermentation for reds

70% of the total weight

Skin contact for aromatic whites (Sauvignon Blanc, Semillon, Muscat, Riesling, Gewuztraminer, Viognier)

  • 5-10 C
  • few to 24 hours
  • pectolytic enzyme

Finest aromatic wines

  • very gentle whole-bunch pressing
  • no skin contact
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19
Q

Types of press?

A 
Vertical screw press (basket press)
Horizontal screw press (e.g. Vaslin)
Pneumatic press (e.v. Willmes)
Tank press (pneumatic press with inert gas)
Continuous screw press
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20
Q

Vertical screw press (basket press)?

A

Vertical screw press (basket press)

  • simple and easy; clear must or wine
  • slow, labour intensive; extraction of bitter phenolics; oxidation
  • high-class wineries; champagne
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21
Q

Horizontal screw press (e.g. Vaslin)?

A

Horizontal screw press (e.g. Vaslin)

  • more efficeint in terms of time and labour; simple; can be automated; prevent oxidation with inert gases
  • rather coarse juice; extraction of bitter phenolics; high pressure reduces quality
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22
Q

Pneumatic press (e.v. Willmes)?

A

Pneumatic press (e.v. Willmes)

  • low pressure; good extraction; less bitter phenolics; high quality juice
  • very slow
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23
Q

Tank press (pneumatic press with inert gas)?

A

Tank press (pneumatic press with inert gas)

  • no oxygen contact; high quality juice
  • very slow; costly
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24
Q

Continuous screw press?

A

Continuous screw press

  • high throughput; less labour-intensive and time consuming
  • poor quality; bitter phenolics
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25
Must Treatments?
``` Before fermentation SO2 Clarification Enrichment or Chaptalisation Must concentration De-acidification Acidification Tannin Bentonite Flavour and colour enhancing enzymes Oxygen ```
26
SO2 (Sulfur dioxide) in winemaking?
Prevent oxidation and premature fermentation Kill bacteria (for whites) Stun weaker yeasts Improve extraction of polyphenols from skins (for reds)
27
Four properties of SO2 (Sulfur dioxide) in winemaking?
Four properties: Antiseptic - kills microorganisms (acetobacter/wild yeasts) Antioxidant - binds with oxygen Antioxidasic - denatures oxidasic enzymes Combines with acetaldehyde (by-product of oxidation)
28
Four forms of SO2?
potassium metabisulphate powder compressed and liquidified SO2 gas SO2 in solution (5%) Burning sulphur tablets or candles
29
SO2 levels?
Based on style of wine, health of grapes, pH Lower for organic wines Recommeded - White: 60-100 mg/l Red: 10-60 mg/l Limits - Dry white: 200 mg/l Dry red: 150 mg/l (red wines contain natural anti-oxidants) Off-dry white (5g/l sugar): 250 mg/l BA/TBA/Sauternes: 390 mg/l (binding power of sugars)
30
Free, bound and total SO2?
Free - active, protective, molecular SO2 & sulphurous acid Bound - combined with sugars, aldehydes, ketones, inactive Total - free + bound
31
Pre-fermentation clarification?
Remove solid particles Produce cleaner flavours, more finesse, less bitter Depend on - state of the harvest - grape processing method - wine style required (little for full-bodied, complex wines; more for delicate and highly aromatic wines)
32
Clarification methods?
Cold settling (common) Centrifugation Diatomaceous earth filtration Flotation
33
Clarification method - Cold settling?
Cold settling (common) - debourbage - by gravity - 12 to 24 hours - cool temperature (5-10 C) - clear must racked off the sediment (lees) - pectolytic enzymes and SO2
34
Clarification method - Centrifugation?
Centrifugation - high level of clarity - harsh, high risk of oxidation, expensive - large wineries
35
Clarification method - Diatomaceous earth filtration?
Diatomaceous earth filtration - for aromatic grapes - can strip the must of nutrients for fermentation
36
Clarification method - Flotation?
Flotation - bubbling small amounts of N, CO2 or air - catching and floating solid particles - skimmed off by a rotary suction device - large wineries or cooperatives
37
Enrichment?
Adding sugar to increase potential alcohol No effect on wine sweetness Permitted in cool regions Unusually cool summer or early harvest in warm regions Not allowed in Italy/Spain
38
Forms of sugar for enrichment?
Sucrose (beet sugar) or cane sugar - chaptalisation RCGM (rectified concentrated grape must) - enrichment 1 kg of sugar increase vol of wine by 0.63 l White: 1% abv require 17 g/l sugar Red: 1% abv require 19 g/l sugar (evaporation due to higher fermentation temp & pumping over)
39
Must concentration techniques?
Vacuum evaporation Reverse osmosis Cryoextraction
40
Vacuum evaporation?
Vacuum evaporation - water evaporates at low temperature of 20 C - loss of aromas, hence use of chilled aroma trap
41
Reverse osmosis?
Reverse osmosis - high pressure applied to must against a membrane filter - no loss of aromas - also used to remove alcohol and volatile acididty
42
Cryoextraction?
Cryoextraction - chill grapes to remove water in from of ice - no loss of aromas
43
EU Rules on enrichment?
Wine must be > 8.5% alcohol Enriched wine 2% or reduce vol by 20% (whichever is lower) Only one enrichment method and no blending of differently enriched wines
44
Potential alcohol?
alcohol level that would result if all sugars are fermented
45
Actual alcohol?
actual alcohol level after fermentation
46
Residual sugar?
``` unfermented sugars (natural or added) left in the wine expressed as g/l or % ```
47
Total alcohol?
actual alcohol + potential alcohol from residual sugar
48
Natural alcohol?
total alcohol in an un-enriched must or wine
49
De-acidification?
Tartaric acid cannot be reduced by > 1 g/l Not permitted in warmest regions - CIII(b) Increase pH, therefore risk of microbial infection and decrease effectiveness of SO2
50
De-acidification methods (Tartaric only)?
Tartaric only - potassium bicarbonate (potassium tartrate crystals) - calcium carbonate (leaves high level of calcium tartrate)
51
De-acidification methods (Malic only)?
Malic only | - malolactic fermentation
52
De-acidification methods (Both tartaric and malic)?
Both tartaric and malic - double-salt de-acidification - Acidex (specifially prepared calcium carbonate with small amount of calcium tartrate-malate) - calcium tartrate-malate crystals
53
Acidification?
``` "buffering" effects logorithmic pH scale - more acid to alter pH from 3.2 to 3.0 than from 3.8 to 3.6 CII and CIII zones Not in Rhone ``` Tartaric acid for acidification - 1.5 g/l in must; 2.5 g/l in wine Citric acid - 1 g/l in must - never added before fermentation - metabolised by yeast and bacteria to form acetic acid
54
Tannin?
Added before fermentation Protection from oxidation Stablilize colour Improve mouth feel
55
Bentonite?
Fining agent in form of clay Remove proteins Non-selective and remove flavour compounds
56
Flavour and colour enhancing enzymes?
``` Aid juice extraction Optimise extraction of aroma precursors Improve colour extraction Increase efficiency of settling Developed from fungi Added at crushing ```
57
Use of oxygen in winemaking?
Hyperoxidation Development of yeasts at start of fermentation Revitalization of yeast Micro-oxygenation of harsh polyphenols in barrels Anaerobic maturation after bottling (not for screwcaps) Add complexity and character in anaerobically made wines
58
Oxidases?
Laccase - grey rot - SO2 resistant - pasteurisation (heating must to 65-70 C) Tyrosinase - controlled by SO2 Copper and iron
59
Reductive (anaerobic) handling?
Minimize exposure to oxygen SO2 Low temperatures Inert gases used to flsuh out presses, pipes, vats Reductive taint - sulphur dioxide becomes hydrogen sulphide
60
Oxidative (Aerobic) handling?
Minimal use of SO2 Controlled exposure to oxygen Develop complex flavours and aromas Enzymatic oxidation of phenolics is encouraged Form insoluble polymers removed by clarification More stable wine Production of oloroso Sherry, tawny Port, vin jaune from the Jura, some Tokaji
61
Hyperoxidation?
Bubbling air through the juice Colour stabilisation in white wines Can decrease aromalics (e.g. Sauvignon Blanc)
62
Effects of excessive oxygen?
Acetaldehyde (ethanal) --> flat sherry-like flavour Bitter-tasting components from oxidation of phenolics Spoilage bacteria, e.g. acetic bacteria
63
Ascorbic acid?
Vitamin C Antioxidant No antiseptic effect Used without SO2 --> hydrogen peroxide (bleaching agent)
64
Alcoholic fermentation?
glucose/fructose + yeasts --> ethanol + CO2 + energy 180 g sugar --> 92 g alcohol + 88 g CO2 Saccharomyces yeast 16-18 g/l sugar needed to produce 1% abv (8 g/l) Glucose - dominant early in ripening process - yeast prefer glucose Frutose - dominant in very ripe grapes - late harvest or botrytis-affected grapes - difficult to ferment fructose-rich grape must to dry wine
65
Rate of fermentation?
``` Concentration of sugars Availability of oxygen Temperature Type and quantity of yeasts Nutrient content of the must SO2 ```
66
Fermentation ceases?
``` All sugar consumed Alcohol reaches 15% killing yeasts Increasing pressure of CO2 to 7 atmospheres Chilling to low temperature (5 C) SO2 Pasteurisation (80 C for a few second) Removing yeasts (filtration, centrifuge) Fortification with spirit ```
67
By-products of fermentation?
``` Glycerol (Glycerine) - smoothness and weight of wine Acetaldehyde Ethyl acetate (nail polish) Aroma esters Fusel oils, e.g. methanol ```
68
Fermentation vessels?
Stainless steel tanks Wooden fermentation vessels Cement tanks
69
Stainless steel tanks?
Stainless steel tanks - easy to clean and maintain - allow temperature control - rotofermenters
70
Wooden fermentation vessels?
Wooden fermentation vessels - piece (228 liters) in Burgundy - barrique (225 litres) in Bordeaux, New World - open top wooden vats - 1000-5000 litres - wood retains heat well, need temp control - difficult to keep clean - chestnut, cherry, acacia & wallnut
71
Cement tanks?
Cement tanks - lined with glass or epoxy - cheap - easy to clean and maintain - no oxygen exchange - simple temp control
72
Uninoculated fermentations?
``` Started by indigenous yeasts - Kloeckera/Hanseniaspora - Candida - Metschnikowia Around 4% alcohol - Saccharomyces takes over - Saccharomyces cerevisiae ```
73
Pros and Cons of Uninoculated fermentations?
Pros: complex wine Cons: off-flavours, oxidation, microbiological spoilage
74
Pied de curve?
Pied de curve - starter culture
75
Inoculated fermentation?
Commercially available active dry yeast - different strains of Saccharomyces cerevisiae - higher tolerance of SO2
76
Pros of Inoculated fermentation?
Pros - active fermentation onset - handle highly clarified juice - fermentation rate more even and easy to control - no off-flavours or aromas - efficient conversion of sugar to alcohol - decreased risk of stuck fermentations - low volatile acidity (acetic acid) production
77
Atributes of Inoculated fermentation?
Attributes - tolerance to higher sugar levels (Lalvin Rhone 2226) - higher glycerol production levels (Maurivin Cru-Blanc) - efficent extraction of phenolics and enhancement of tannin structure for high quality reds (Lalvin Rhone 2323) - low temperature tolerant for very fruity whites (R2) - low foaming (champagne yeasts, e.g. Premier Cuvee for secondary fermentation in bottle) - Sauvignon Blanc yeasts for aroma/thiol fixing (Lalvin K1V-1116)
78
Monitoring and controlling fermentation?
Density Temperature Aeration Finishing the fermentation
79
Density? | Monitoring and controlling fermentation
Density - measures sugar (not alcohol) - Baume (France): relative density - Brix or Balling (Australia, NZ, US): hydrometer measurement - Oechsle (Germany, Switzerland): hydrometer scale - Babo (Italy), same as KMW (Austria)
80
Temperature? | Monitoring and controlling fermentation
Temperature - controls the rate of fermentation - chill white grapes/must in warm climates - fermentation releases heat
81
Aeration? | Monitoring and controlling fermentation
Aeration - yeast needs oxygen - reds: pumping over (remontage) or punching down (pigeage)
82
Finishing the fermentation? | Monitoring and controlling fermentation
Finishing the fermentation - density drops below 1 - 2 g/l of unfermentable sugars in dry wines
83
Optimum fermentation temperature range?
Optimum fermentation temperature range - whites: 10 - 18 C - reds: 20 - 32 C
84
Excessively high fermentation temperature?
Excessively high temperature - oxidation, microbiological spoilage and instability - loss of aroma and flavour compounds, alcohol - slow or stuck fermentation (above 35 - 38 C)
85
Excessively low fermentation temperature?
Excessively low temperature - retention of isoamyl acetate (banana/pear) in whites - poor extraction of colour and tannins in reds - sluggish fermentation - high levels of ethyl acetate and volatile aroma
86
Aromatic dry white wines? | Options for finishing the fermentation
Aromatic dry white wines - chill the new wine - add SO2 (40-100 mg/l) - remove lees (settling or fining agent) - rack clean wine and bottle
87
Full-bodied Chardonnay? | Options for finishing the fermentation
Full-bodied Chardonnay - fermented in oak barrels - extended lees contact, with lees stirring - MLF - after MLF, suphited and left to mature in oak
88
Off-dry white wines? | Options for finishing the fermentation
Off-dry white wines - stop fermentation before dryness - chillded (
89
Sweet fortified wines (Port/vins doux naturels)? | Options for finishing the fermentation
Sweet fortified wines (Port/vins doux naturels) | - add alcohol to > 15% abv
90
Red wines? | Options for finishing the fermentation
Red wines - maceration to extract tannins and pigments - New World: fermentation completed in barrels, then MLF
91
Fermentation problems?
Stuck fermentations Yeast nutrient issues Hydrogen sulphide formation Carbon dioxide poisoning
92
Stuck fermentation results in?
results in - hydrogen sulphide (VA) - microbial spoilage - residual sugar
93
Stuck fermentation is caused by?
caused by - too hot (> 35 C) or too cold - nutrients depleted - alcohol level (uninoculated fermentation)
94
Stuck fermentation is prevented by?
prevented by - adequate aeration at onset of fermentation - 100 - 150 mg/l di-ammonium phosphate (DAP) - 0.5 mg/l thiamine (vitamin B) - temperature control
95
Stuck fermentation "kick-start"?
"kick-start" - adjust temperature - add DAP and thiamine - re-inoculate with Saccharomyces Bayanus
96
Yeast nutrient issues?
Low yeast nutrients in rotten fruit and clarifed must Add DAP (200 mg/l) and thiamine (1.0 mg/l) Ammonium sulphate liberates ammonium and SO2
97
Hydrogen sulphide formation?
Yeasts deprived of nitrogren (ammmonium) Break down amino acids to release H2S Rotten eggs
98
Carbon dioxide poisoning?
Colourless, odourless, potentially lethal Heavier than oxygen Good ventilation required Measure oxygen using a meter
99
White winemaking?
Grapes pressed before fermentation Good quality whites - healthy, ripe grapes - careful and quick processing - protection from oxidation
100
White winemaking Key decisions?
Key decisions - whole bunch press or de-stem and crush before pressing - de-acidify, acidify, increase sugar levels - skin contact (maceration pelliculaire) or press immediately - clarify must before fermentation - inoculate - fermentation vessel - fermentation temperature (14 - 20 C) - lees contact - MLF (No SO2, 16 - 18 C) - oak - maturation prior to bottling
101
Fermentation temperature for whites?
Optimum 14 - 20 C - fruit preservation - > 20 C reduce esters and increase alcohol Aromatic whites - 11 - 15 C to retain fruit esters - 10 - 13 C to retain volatile esters but produce intense smelling esters (isoamyl acetate) After fermentation, lower temp to 12 C for yeast settling
102
Lees contact (white wine production)?
Protect wine from oxidation Add texture Autolysis of yeast in lees Muscadet Reduction problems - H2S --> onion-like mercaptans, difficult to remove - oxygen by lees stirring or wine racking - pass through copper pipe or add copper sulphate Lees stirring (battonage) - wine in barrique (Chardonnay) - barrel stackers with rollers to avoid excess oxygen - bubbling gas in tank
103
Rose winemaking?
Drawing-off method Direct pressing Blending
104
Drawing-off method? | Rose winemaking
Drawing-off method - saignee or bleeding - de-stemmed, crushed and sulphited grapes - 6 - 48 hours of skin contact - cooler temp to retain fruit aromatics and freshness - higher temp for more colouring - fermented at 15 - 20 C - no MLF to retain fresh natural acidity - clarified, stabilised and bottled young - Anjou, Bordeaux Clairet, Cotes de Provence
105
Direct pressing? | Rose winemaking
Direct pressing - freshly harvested red grapes - not to extract too much tannin - pale pink - Cotes de Provence, Languedoc
106
Blending? | Rose winemaking
Blending - Rose Champagne, New World Roses - not permitted in EU for still roses
107
Definition of "red wine"?
A macerated wine. Extraction of solids from grape cluster (specifically from skins, seeds and possibly stems) accompanies the alcoholic fermentation of the juice.
108
Red winemaking?
Skin contact during the alcohol phase and colour of the grape; extraction of phenolic compounds (polyphenolics or polyphenols); pressing after fermentation
109
5 main steps of Red winemaking?
5 main steps - pre-fermentation processing - alcoholic fermentation - draining and pressing - MLF - maturation
110
Two main types of phenolic compounds?
Non-flavonoids | Flavonoids
111
Non-flavonoids?
Non-flavonoids - simple phenolics - benzoic and cinnamic acids
112
Flavonoids?
Flavonoids - catechins (tannin) - resveratrol - anthocyanins (red pigments in skin cells) - tannin can react with anthocyanins to fix colour - pigmented tannins polymerise with age and precipitate out
113
Three factors of phenolic extraction?
Temperature of fermentation DAP management Duration of skin contact
114
Pre-fermentation processing (red wines)?
De-stemming and crushing (not for carbonic maceration) | Fill vessel to
115
Fermentation temperature for reds?
20 - 32 C Higher temp increase breakdown of skin cells and level of dissolution of phenolics Moderate temp (25 C) - good colour extraction - preservation of primary fruit aromas - minimal to moderate tannin extraction Thermovinification - heating grape to 45 C - rather coarse wines with "burnt" aromas
116
Cap management?
Pomace cap Methods - pumping-over (remontage) - punching down (pigeage) - rackand return (delestage) - submerged cap - rotovinification - autovinification
117
French word for Pumping-over?
Remontage
118
Pumping-over Process?
with or without aeration pump, hose, fixed spray head done 1-3 times a day
119
Pumping-over Benefits?
Benefits - simple - good extraction - tank of wine becomes homogenised - aeration prevents reduction, aids yeasts - prevents cap from drying out
120
Pumping-over Wines?
Wines - Cabernet Sauvignon, Merlot - medium to high quality - rich, full-bodied structure - no vegetal or bitter characters
121
French word for Punching down?
Pigeage
122
Punching down Process?
Manual (paddle) Automatic (stainless steel cone attached to a hydraulic piston) Done 1-3 times a day
123
Punching down Benefits?
Benefits - gentle extraction - less harsh or bitter compounds - good disperson of temperature - avoid bacterial spoilage on surface of cap
124
Punching down Disadvantages?
Disadvantages - labour intensive if done manually - Merlot and Cabernet Sauvignon more rustic in flavour
125
Punching down Wines?
Wines | - Pinot Noir and premium Syrah
126
Rack and return?
Delestage Tank is drained into another tank, then pumped back over the cap Done once per day or twice during fermentation - after initial peak of temp - middle of fermentation
127
Rack and return Pros and Cons?
Benefits - complete mixing and breaking up of cap - good aeration - extraction of phenolics - seeds can be removed Disadvantages - too extractive
128
Submerged cap method?
Fermenting fluid filled to over head boards/perforated screen that trap pomace beneath Constant contact
129
Submerged cap method Pros and Cons?
Benefits - good extraction - no risk of pomace cap drying out and VA Disadvantages - extraction can be difficult as skins are compressed
130
Rotovinification?
Rotofermenter - horizontal cylindrical fermentation vessel - motor Wines - inexpensive, bulk reds - premium Barolo
131
Rotovinification Benefits?
Benefits - fast - thorough mixing - good extraction - automatic and computer-controlled - pomace kept wet
132
Rotovinification Disadvantages?
Disadvantages - expensive - robust supporting framework - reduction problems - over extraction
133
Autovinification?
Autovinifier, or Algerian Ducellier system - extended version of pumping-over - sealed vats - CO2 pumps must into top reservoir - cascades back into lower chamber Wines - red Port - light, good quality wine in N Afriaca
134
Autovinification Pros and Cons?
Benefits - no external power - fully automated - good extraction of colour and tannins Disadvantages - difficult to control rate of extraction
135
Fermentation management of reds?
``` Complexity of maceration dynamics Monitor density and temp Control of temp Control of aeration Pumpovers and/or cap punching Skin contact time (post-ferementation maceration) ```
136
Duration of skin contact?
Extraction enhanced by - higher temp - increase in alcohol Extent of phenolic extraction - avoid extraction from poor quality grapes - shorter (around 8 days) for light, easy, early-drinking reds - longer (3 weeks) for full-bodied reds - extended (> 1 months) for high quality vintages Pectolytic enzymes to increase extraction Anthocyannis extracted first (temp) Tannin extracted by higher temp and alcohol
137
Draining and pressing?
Free-run wine and press wine Fining of press wine Residual sugar in press wine to ferment out
138
Maturation?
Lees contact - reducing properties - fuller, smoother wines - mannoproteins released by lees autolysis - inhibit tartrate crystalization - bind with tannins to reduce astringency
139
Malolactic fermentation (MLF)?
Conversion of malic acid in a wine to lactic acid through the action of naturally-occurring or added bacteria Traditionally in tank Today, commonly in barrel for better oak integration
140
Malolactic fermentation (MLF) Benefits?
Biologically more stable wine Softer, rounder acidity - malic is sharp (unripe apples) - lactic is softer (milk)
141
Malolactic fermentation (MLF) By-products?
By-products - diacetyl (buttery richness) - higher VA
142
``` 3 species of lactic acid bacteria? Malolactic fermentation (MLF) ```
- Lactobacillus - Leuconostoc - Pediococcus
143
Conditions for MLF?
pH between 3.3 - 3.5 | Temp between 18 - 25 C
144
Preventing MLF?
Clarify (remove nutrients and bacteria) SO2 addition after primary fermentation Low storage temp (
145
Encouraging MLF?
``` Keep wine in lees Low levels of SO2 Warm temp (18 - 22 C) pH above 3.3 Add Leuconostoc oenos (freeze-dried) ```
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Monitoring MLF?
CO2 Reduction of malic acid Paper chromatography Enzymatic analysis
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Effects of MLF?
Deacidification - cool climates - incomplete ripening Stability - consuming bacteria nutrients - useful in reds as lack of protection of added SO2 Loss of primary fruit aromas - detrimental to aromatic whites Addition of aromatic compounds e.g. diacetyl - spoil fruit aromas of Riesling or Sauvignon Blanc Increase VA - breakdownof citric acid Spoliage if lactic acid bacteria not controlled - SO2, low pH, equipment hygiene Should never occur in the bottle
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Carbonic maceration?
Fermentation within berries; no yeast; anaerobic respiration of grapes converts sugars to ethanol ``` Whole bunch Blanket with CO2 Intercellular fermentation 2% abv and aromatic compounds Decrease in malic acid, increase in pH 1-3 weeks Aromas of bananas, kirsch, cherry, plum ```
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Semi-carbonic maceration?
Beaujolais Comibination of extra- and intracellular fermentation No CO2 blanket Vat filled with grape bunches Fermentation of crushed bunches at bottom release CO2 Intercellular fermentation of upper layer bunches Deeply coloured, fruity wines with soft tannins
150
Thermovinification?
Heat to 60 - 80 C for 20 - 30 minutes then cool to ferementation temp Max colour extraction "Time saver" Destroy damaging oxidative enzymes in rotten grapes Pectolytic enzymes and aromas destroyed Not for premium reds
151
Flash expansion?
Flash detente Pre-heat grapes to 65 - 90 C and place in vacuum Grapes cooled immediately to 30 - 35 C Rapid release of anthocyanins and tannins Juice drained off
152
Sparkling winemaking?
``` Traditional Method (methode champenoise) Transfer Method Tank Method (cuve close or Charmat) Carbonation (Pompe bicyclette) Asti Method & Methode Ancestrale ```
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``` Traditional Method (methode champenoise)? Sparkling winemaking ```
Traditional Method (methode champenoise) - produce dry base wine - no SO2 added at end of fermentation - add liqueur de tirage and yeast - bottled and sealed (cork or crown seal) - secondary fermentation to increase 1.2 - 1.3% abv - autolysis of yeasts to add complexity - riddled by hand or automatic ridding machines (remuage) - disgorgement - add liqueur d'expedition - sealed by cork and wire cage (muselet) - further aging - packing and distribution - Champagne, Cava, premium sparkling wines - complex wines, bready, biscuit flavours
154
Transfer Method? | Sparkling winemaking
Transfer Method - fermented wine emptied into pressurized tank - cooled to -5 C - add dosage (sweetening wine) - filter to bottle - slight loss of quality - mid-market New World sparkling wines
155
``` Tank Method (cuve close or Charmat)? Sparkling winemaking ```
Tank Method (cuve close or Charmat) - secondary fermentation in sealed pressurised tank - lees contact - sweetened, filtered and bottled under pressure - lower production costs - German Sekt and Prosecco - coarser and broader bubbles
156
Carbonation (Pompe bicyclette)? | Sparkling winemaking
Carbonation (Pompe bicyclette) - chill wine - bubble carbon dioxide into it - very infereior method
157
Asti Method & Methode Ancestrale | Sparkling winemaking
Asti Method & Methode Ancestrale - Moscato - must pumped into a pressure vessel and yeast added - CO2 allowed to escape to atmosphere - 5% abv: valves closed to trap CO2 - 6-9% abv and 60-100 g/l sugar: cooled to 0 C - clarified, filtered and bottled
158
Fortified Winemaking Types?
Types - Port, Sherry, Madeira - Muscat in Australia, S France, Greece, Italy - Vin de Constance (S Africa) - Malaga (S Spain) - Mavrodaphne (Greece) - Commandaria (Cyprus)
159
Fortified Winemaking Methods?
Methods - fortified during fermentation - fortified after fermentation
160
Fortification during fermentation?
Vins doux naturels | Port
161
Vins doux naturels?
Vins doux naturels - Muscat, Grenache (S France) - at 5% abv, add high-strength grape spirit (95% abv) - 15 - 18% abv
162
Port?
Port - maceration in granite troughts (lagares) - fermentation at high temp (> 30 C) - drain wine at 6 - 9% abv - 1 part of spirit (77 - 79% abv) to 4 parts of wine - 18 - 19% abv
163
Port maturation?
Maturation | - 550 litre "pipe"
164
Port quality?
Port quality - base wine - single vintage or blend - time in cask - filtered?
165
Port styles?
Styles | - Ruby Port (
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Fortification after fermentation?
Sherry - Town of Jerez - Palamino, Pedro Ximenez - 70% free run for Finos, next 20% for Oloroso - acidified with tartaric acid - 600 litre oak butts - uninoculated fermentation (25 - 30 C) - dry wine, low in alcohol (11 - 11.5%) - Finos/flor (14.5 - 15.5%) (biologically aged) - Oloroso (18%) (oxidatively aged) - Amontillado (aged both biologically an oxidatively)
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Solera system?
Criadera (row) - simple solera: 3 - 4 criaderas - complex solera: 14 criaderas - bottom row called Solera Fractional blending - no more than 1/3 of contents drawn - complex wines - replenish nutrients for flor Finos: 3 - 5 yrs Amontillados/Olorosos: 5-10 yrs Swettened prior to bottling - Pedro Ximenez (Cream Sherries and Sweet Orlorosos) - concentrated grape juice (Pale Cream Sherries) Membrane-filtered for Finos and Manzanilla (salty)
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Sweet wines?
3 main methods - interrupting the fermentation - adding a sweet component - concentrating the natural sugars
169
Interrupting the fermentation?
Fortification - Vins doux naturels e.g. Muscat de Beaumes de Venise - Moscatel de Valencia - Liqueur Muscats e.g. Rutherglen Muscat Add SO2 and lower temp
170
Adding a sweetening component?
RCGM Sussreserve (unfermented grape juice) - German QbA wines - Rheingau, Rheinhessen, Mosel
171
Concentration of sugars?
Drying, e.g. on straw mats Freezing Noble rot
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Drying, e.g. on straw mats? | Concentration of sugars
Drying, e.g. on straw mats - passerillage - Amarone, Vin Santo (Italy, Santorini), PX Sherry (Spain)
173
Freezing? | Concentration of sugars
Freezing | - Icewine/Eiswein
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Noble rot? | Concentration of sugars
Noble rot - botrytis cinerea - Riesling, Semillon, Chenin Blanc - Sauternes, Monbazillac in France; Tokaji in Hungary; Beerenauslese and Trokenbeerenauslese in Germany and Austria; botrytis Semillon in Australia

WSET Diploma (10 decks)

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