WSET LEVEL 4 COMPREHENSIVE EXAMS 2025/2026
QUESTION AND SOLUTIONS RANKED A+
✔✔Stopping Fermentation (6) - ✔✔1. Naturally when most sugars fermented
2. Increase pressure of CO2 to 7 atmospheric pressures - temporary
3. Reducing the temperature to 5C - temporary
4. Kill the yeast - heat to 80C to pasteurize - temporary
5. Remove the yeast - by filter or centrifuge - temporary
6. Add alcohol / fortify - which kills the yeast - permanent
✔✔Stuck Fermentation - ✔✔Too cold temp or lack of nutrients
Pump over to give a burst of oxygen, add yeast nutrient
Surefire way is to blend stuck vat into an active vat
✔✔Naturally Sweet Wines - Yeast Impact - ✔✔Rising sugars and alcohol weaken yeast
through osmotic pressure
Nutrients are depleted, noble rot inhibits growth
Chill and add SO2
✔✔Malo-lactic Fermentation - Process & presence in Red & White - ✔✔Bacteria
transforming harsh malic acid into smoother lactic acid
HOOC.CHOH.CH2.COOH = HOOC.CHOH.CH3 + CO2
Nearly all Red wines smoother & more stable as it consumes bacteria
Full body White - Chardonnay (diacetyl - butter)
Loss of some fruit in both Red & White
✔✔Malo-lactic bacteria strains - ✔✔Lactobacillus
Leuconostoc
Pediococcus
Typically present and spontaneous
Oenococcus - cultured version
✔✔How to encourage / discourage malo-lactic - ✔✔Encourage - Raise temp & no SO2
Discourage - Lower temp & SO2
✔✔Red Wine Fermentation Vessels - ✔✔Historically 50hl vats (good heat dissipation)
Cement lined with tiles or epoxy resin
Stainless Steel vats
✔✔Maceration - ✔✔Pre-Ferment "cold soak"
4C - 15C to prevent fermentation
Extract aroma from skins
Post Ferment
Extract polyphenols
,Careful not to get too tannic
Warmer post fermentation temperatures
Tannins and anthocyanins interact producing more stable colors
✔✔Punch Down "Why?" - ✔✔Extract further color and tannin from skins
Prevent the formation of acetic acid which would turn the vat to vinegar
✔✔Traditional Punch Down - ✔✔Barrel by barrel with a pole and disc several times /
day - very dangerous
Machine punch down with pistons
✔✔Submerged Cap Process - ✔✔Perforated screen just below the surface
Eliminates VA
Prevents full extraction
Can trap CO2 and cause too much pressure
✔✔Pumping Over Systems - ✔✔Pump liquid from bottom over the top of the cap
Manual or automatic
Good extraction as juice trickles through cap
✔✔Delestage - ✔✔Rack & Return
Extreme pump over
Entire vat run off into another tank then pumped back into original over the cap
✔✔Autovinifier - ✔✔Pump over mechanism using natural energy from fermentation
Algeria and Duoro where power was not assured
✔✔Rotary Fermentor - ✔✔Cement mixer - blade one direction, tube other direction
Can be harsh
✔✔Thermo Vinification - ✔✔Heat grapes to 60C - 75C and hold for 20 min to extract
color
Can lead to cooked flavor
Beaucastel does it in a way that doesn't harm grapes
✔✔Flash Detente - ✔✔Heat grapes to 95C for several minutes then place in vacuum
and rip apart
Super rich wine that needs to be blended with regular
✔✔Carbonic Maceration Stages (7) - ✔✔1. Vat filled with CO2 at atmospheric pressure
2. Filled with whole bunches of undamaged grapes (if damaged normal fermentation will
start)
3. Complex metabolic change akin to dying, grape attacked by own enzymes releasing
sugars, anaerobiosis
4. Enzymes attack sugars and turn into alcohol, intracellular fermentation
,5. Temp raises to 30C - 35C and goes for 5 - 15 days, alcohol to 3%
6. Contents become semi-liquid, pressed as usual (press juice better)
7. Transfer to a normal vessel and normal extracellular fermentation occurs
✔✔Variations on Carbonic Maceration (2) - ✔✔Whole Bunch Fermentation - Beaujolais;
grapes at bottom of vat get crushed and start normal fermention, CO2 rises and flushes
out air promoting intracellular fermentation
Whole Berry Fermentation - bunches destemmed and intracellular happens in berries
and normal occurs on escaped juice
✔✔Methods of Rose Production (4) - ✔✔Short Maceration - best; short maceration on
skins for right color and flavor
Saignee - bled off after a couple days to produce rose, but also concentrates remaining
must with more skin contact
Vin d'une nuit - one night of skin maceration
Double Pasta - Spanish, short maceration then transfer skins to another typical red wine
to make it black
✔✔Red Wine Production Process - ✔✔De Stemming
Crushing
Sulphiting
Adjustment to Acid & Sugar
Heat Treatment
Maceration on Skins
Fermentation with Skins
Post-Fermentation Maceration
Draining
Pressing
Clarification
✔✔White Wine Production Processs - ✔✔De-Stemming
Crushing
Sulphiting
Skin Contact
Draining
Pressing
Clarification
Adjustment to Acid & Sugar
Fermentation
✔✔White Wine Fermentation Temperature - ✔✔Generally cooler to preserve aromas
15C - 20C
, ✔✔Skin Contact in White Wine - ✔✔Typically remove as quickly as possible to prevent
extraction of harsh and bitter polyphenols
But many flavors lie in the skin cells next to the grape pulp so some contact is beneficial
for aromatic grapes
Crush gently and leave for a few hours at a cool temperature
Or leave freshly picked grapes for a day or two in a cool place
✔✔White Wine Fermentation Vessels (2) Pros / Cons - ✔✔Stainless Steel - Clean &
Fresh Wine, easy to clean & sterilize
Barrels - More complexity
✔✔Sur-Lie - ✔✔On the Lees
Lees - Deposit at the end of fermentation (yeast cells, grape fragments)
More flavor (toasty) and complexity
✔✔Battonage - ✔✔Lees after a few months begin to decompose and lead to reductive
condition
Stirring the lees (battonage) introduces oxygen to prevent reductive taint and gets wine
into contact with lees for more flavor
✔✔Prevention of Oxygen in White Wine - ✔✔White wines have no polyphenols to be
anti oxidants
Pressing in tank press flushed with Nitrogen
Moving it via pipes flushed with Nitrogen or CO2
Ensuring all joints are sealed tight
Keeping tanks topped up or blanketed with Nitrogen
Using Sulpher Dioxide and / or ascorbic acid
Monitoring levels of dissolved oxygen
✔✔Sweet Wines (6) - ✔✔Carafe Wines - add concentrated grape must to fully
fermented wine
German QbA Wines - add preserved grape juice to fully fermented wine
Cuvee & German QmP - Overripe grapes with concentrated sugars
Amarone & Vin Santo - Grapes picked when ripe and dried
Tokai, Sauterenes, German - Noble Rot; Botrytis cinerea
Eiswein/Icewine - Frozen grapes
✔✔Carafe Wines - ✔✔Cheapest and Simplest way to make a sweet whine
Add concentrated grape must
Medium Dry White Wine or Sweet White Wine
✔✔Cheap German Sweet Wines - ✔✔Only for QbA Wines
Add Sussreserve - unfermented preserved grape juice
QUESTION AND SOLUTIONS RANKED A+
✔✔Stopping Fermentation (6) - ✔✔1. Naturally when most sugars fermented
2. Increase pressure of CO2 to 7 atmospheric pressures - temporary
3. Reducing the temperature to 5C - temporary
4. Kill the yeast - heat to 80C to pasteurize - temporary
5. Remove the yeast - by filter or centrifuge - temporary
6. Add alcohol / fortify - which kills the yeast - permanent
✔✔Stuck Fermentation - ✔✔Too cold temp or lack of nutrients
Pump over to give a burst of oxygen, add yeast nutrient
Surefire way is to blend stuck vat into an active vat
✔✔Naturally Sweet Wines - Yeast Impact - ✔✔Rising sugars and alcohol weaken yeast
through osmotic pressure
Nutrients are depleted, noble rot inhibits growth
Chill and add SO2
✔✔Malo-lactic Fermentation - Process & presence in Red & White - ✔✔Bacteria
transforming harsh malic acid into smoother lactic acid
HOOC.CHOH.CH2.COOH = HOOC.CHOH.CH3 + CO2
Nearly all Red wines smoother & more stable as it consumes bacteria
Full body White - Chardonnay (diacetyl - butter)
Loss of some fruit in both Red & White
✔✔Malo-lactic bacteria strains - ✔✔Lactobacillus
Leuconostoc
Pediococcus
Typically present and spontaneous
Oenococcus - cultured version
✔✔How to encourage / discourage malo-lactic - ✔✔Encourage - Raise temp & no SO2
Discourage - Lower temp & SO2
✔✔Red Wine Fermentation Vessels - ✔✔Historically 50hl vats (good heat dissipation)
Cement lined with tiles or epoxy resin
Stainless Steel vats
✔✔Maceration - ✔✔Pre-Ferment "cold soak"
4C - 15C to prevent fermentation
Extract aroma from skins
Post Ferment
Extract polyphenols
,Careful not to get too tannic
Warmer post fermentation temperatures
Tannins and anthocyanins interact producing more stable colors
✔✔Punch Down "Why?" - ✔✔Extract further color and tannin from skins
Prevent the formation of acetic acid which would turn the vat to vinegar
✔✔Traditional Punch Down - ✔✔Barrel by barrel with a pole and disc several times /
day - very dangerous
Machine punch down with pistons
✔✔Submerged Cap Process - ✔✔Perforated screen just below the surface
Eliminates VA
Prevents full extraction
Can trap CO2 and cause too much pressure
✔✔Pumping Over Systems - ✔✔Pump liquid from bottom over the top of the cap
Manual or automatic
Good extraction as juice trickles through cap
✔✔Delestage - ✔✔Rack & Return
Extreme pump over
Entire vat run off into another tank then pumped back into original over the cap
✔✔Autovinifier - ✔✔Pump over mechanism using natural energy from fermentation
Algeria and Duoro where power was not assured
✔✔Rotary Fermentor - ✔✔Cement mixer - blade one direction, tube other direction
Can be harsh
✔✔Thermo Vinification - ✔✔Heat grapes to 60C - 75C and hold for 20 min to extract
color
Can lead to cooked flavor
Beaucastel does it in a way that doesn't harm grapes
✔✔Flash Detente - ✔✔Heat grapes to 95C for several minutes then place in vacuum
and rip apart
Super rich wine that needs to be blended with regular
✔✔Carbonic Maceration Stages (7) - ✔✔1. Vat filled with CO2 at atmospheric pressure
2. Filled with whole bunches of undamaged grapes (if damaged normal fermentation will
start)
3. Complex metabolic change akin to dying, grape attacked by own enzymes releasing
sugars, anaerobiosis
4. Enzymes attack sugars and turn into alcohol, intracellular fermentation
,5. Temp raises to 30C - 35C and goes for 5 - 15 days, alcohol to 3%
6. Contents become semi-liquid, pressed as usual (press juice better)
7. Transfer to a normal vessel and normal extracellular fermentation occurs
✔✔Variations on Carbonic Maceration (2) - ✔✔Whole Bunch Fermentation - Beaujolais;
grapes at bottom of vat get crushed and start normal fermention, CO2 rises and flushes
out air promoting intracellular fermentation
Whole Berry Fermentation - bunches destemmed and intracellular happens in berries
and normal occurs on escaped juice
✔✔Methods of Rose Production (4) - ✔✔Short Maceration - best; short maceration on
skins for right color and flavor
Saignee - bled off after a couple days to produce rose, but also concentrates remaining
must with more skin contact
Vin d'une nuit - one night of skin maceration
Double Pasta - Spanish, short maceration then transfer skins to another typical red wine
to make it black
✔✔Red Wine Production Process - ✔✔De Stemming
Crushing
Sulphiting
Adjustment to Acid & Sugar
Heat Treatment
Maceration on Skins
Fermentation with Skins
Post-Fermentation Maceration
Draining
Pressing
Clarification
✔✔White Wine Production Processs - ✔✔De-Stemming
Crushing
Sulphiting
Skin Contact
Draining
Pressing
Clarification
Adjustment to Acid & Sugar
Fermentation
✔✔White Wine Fermentation Temperature - ✔✔Generally cooler to preserve aromas
15C - 20C
, ✔✔Skin Contact in White Wine - ✔✔Typically remove as quickly as possible to prevent
extraction of harsh and bitter polyphenols
But many flavors lie in the skin cells next to the grape pulp so some contact is beneficial
for aromatic grapes
Crush gently and leave for a few hours at a cool temperature
Or leave freshly picked grapes for a day or two in a cool place
✔✔White Wine Fermentation Vessels (2) Pros / Cons - ✔✔Stainless Steel - Clean &
Fresh Wine, easy to clean & sterilize
Barrels - More complexity
✔✔Sur-Lie - ✔✔On the Lees
Lees - Deposit at the end of fermentation (yeast cells, grape fragments)
More flavor (toasty) and complexity
✔✔Battonage - ✔✔Lees after a few months begin to decompose and lead to reductive
condition
Stirring the lees (battonage) introduces oxygen to prevent reductive taint and gets wine
into contact with lees for more flavor
✔✔Prevention of Oxygen in White Wine - ✔✔White wines have no polyphenols to be
anti oxidants
Pressing in tank press flushed with Nitrogen
Moving it via pipes flushed with Nitrogen or CO2
Ensuring all joints are sealed tight
Keeping tanks topped up or blanketed with Nitrogen
Using Sulpher Dioxide and / or ascorbic acid
Monitoring levels of dissolved oxygen
✔✔Sweet Wines (6) - ✔✔Carafe Wines - add concentrated grape must to fully
fermented wine
German QbA Wines - add preserved grape juice to fully fermented wine
Cuvee & German QmP - Overripe grapes with concentrated sugars
Amarone & Vin Santo - Grapes picked when ripe and dried
Tokai, Sauterenes, German - Noble Rot; Botrytis cinerea
Eiswein/Icewine - Frozen grapes
✔✔Carafe Wines - ✔✔Cheapest and Simplest way to make a sweet whine
Add concentrated grape must
Medium Dry White Wine or Sweet White Wine
✔✔Cheap German Sweet Wines - ✔✔Only for QbA Wines
Add Sussreserve - unfermented preserved grape juice
