SUMMARY
WSET4: D5
FORTIFIED WINES
Iwan Wiering RV, 2025-2026
www.wijnlerendrinken.nl
, Iwan Wiering RV, Summary WSET4 D5: Wine Production, 2025-2026
Summary WSET4
D5 Fortified Wines
Iwan Wiering:
I am a Dutch wine teacher, music teacher and conductor. In 2020 I graduated WSET3. In 2021 I
aced all 4 exams (3 theory modules and 1 tasting module) at the Dutch Wine Academy in 1 day,
becoming “Registervinoloog van de Wijnacademie”. In 2023 I started studying for the WSET4
Diploma. I hope this summary will help you ace your D5 exam, as it helped myself to get
prepared for the exam.
In the last few years I gathered many digital maps. Please check www.wijnlerendrinken.nl for
more information on how to take advantage on them on a small cost.
Please use a licensed purchased copy of this summary only, since I put a lot of time and effort in
writing it. Diploma Course will cost you around Euro 10.000,00 at least. Please don’t economize
for the last few Euros, but let me be of a little profit instead. This way I can keep on writing many
documents and summaries to your advantage, and keep them updated.
As WSET stimulates ‘talking around the subject’ and ‘flair’ to gain higher marks, I added some
useful extra info from the ‘Sherry Academy’ and the ‘School of Port’ in this summary, that
doesn’t show in the textbook but might help you to a higher percentage.
Please also check some useful podcasts on https://eatsleepwinerepeat.co.uk/podcasts/ as
they can be very helpful.
Cheers and thanks, Iwan.
2
, Iwan Wiering RV, Summary WSET4 D5: Wine Production, 2025-2026
List of Abbreviations
DO Denominación de Origen
IVBAM Instituto do Vinho, do Bordado e do Artesanato da Madeira
IVDP Instituto dos Vinhos do Porto e do Douro
IVP Instituto do Vinho do Porto
LBV late bottled vintage
PDO Protected Denomination of Origin
PGI Protected Geographical Indication
PX Pedro Ximénez
RCGM rectified concentrated grape must
SAT Systematic Approach to Tasting
VDN Vins Doux Naturels
VOS Vinum Optimum Signatum / Very Old Sherry
VORS Vinum Optimum Rare Signatum / Very Old Rare Sherry
VSP vertical shoot position
VVO very very old
3
, Iwan Wiering RV, Summary WSET4 D5: Wine Production, 2025-2026
1: Key Choices Affecting Style, Quality
and Price in Fortified Wines
Learning Objectives:
1. Describe the process of fortification.
2. Explain how maturation options impact on the style, quality and price of fortified wines.
3. Explain how winemaking and post-fermentation options impact on the style, quality and price of
fortified wines.
Red, white, rosé; dry to sweet; youthful and aromatic to fully developed and oxidative.
GRAPE VARIETY
May provide own aroma/flavour to wine (VDNs from Muscat, protective winemaking, early
release) or be simply used as neutral base for flavours of maturation.
Rutherglen Muscat (wines aged in warm, oxidative conditions), aromas Muscat still noticeable
in best wines.
Palomino (neutral variety): Sherry aromas from maturation process. Combination bone-dry
palate, low glycerol, pungency from high acetaldehyde can give sensation similar to acidity in
Fino and Manzanilla, but acidity is low (characteristic of Palomino).
Structural components (acidity and, in black grapes, colour and tannin) important factors.
Madeira (notable for high acidity) number of varieties, such as Sercial and Verdelho, with
naturally high acidity.
Colour important consideration in red wines. Port usually blend, attaining suitable level of
colour in base wine. Basic Tawny Port needs to look aged in short time: made from wines that
are light in colour compared to Vintage Port (expected to retain deep colour over decades of
bottle maturation, includes Touriga Nacional and Sousão).
Influence tannin: high levels not required nor desirable in early drinking styles of Ruby Port or
Maury Grenat. By comparison, role of tannins in colour stability makes medium (+) or high levels
beneficial in long-aged wines. Tannins soften with age, and can become integrated and provide
necessary structure and balance on palate.
VINEYARD SITE
Vineyard location and climate important influences on base material fortifieds. Douro vineyards
scored according to location, aspect, altitude: determines how much Port wine plot can
produce. Vintage Ports come from plots known to produce outstanding-quality wines that age
well. Languedoc Muscat de Frontignan: slightly fuller wines with riper flavours from low altitude
vineyards than high-altitude sites Muscat de St-Jean-de-Minervois.
Region Soil Climate Vineyards
Sherry Albariza: limestone, 36° North, 0-90 m. Hot mediterranean 7,000 ha. Cordon trained + spur pruned,
silica, clay with hot, dry summers and mild VSP: open canopy, mechanisation, reduces
(Palomino) relatively warm winters, no frost. disease pressure. Gentle 10–15% slopes.
Barros: more clay Poniente – Levante. Challenge: Albariza crusts. Troughs/gullies catch winter
Arenas: sandy sunburn. Low disease pressure, but rain: aserpia.
(Moscatel) mildew, European grapevine moth
(pheromone traps).
Port Stony, shallow, free- Warm continental: hot summers, cold 32,000 ha. Steep slopes. Cordon trained +
draining, poor. winters. Shelter from Serra do Marão: spur pruned or head trained + cane pruned.
Schist splits in warmer and drier than Porto. VSP, summer pruning, fertilisers.
4
, Iwan Wiering RV, Summary WSET4 D5: Wine Production, 2025-2026
vertical layers: deep Baixo Corgo (west, wettest), Cima Socalcos: trad narrow terraces supported
rooting Corgo, Douro Superior (east, driest). by walls of dry rock.
Patamares: terraces supported by steep
earth ramp, cheaper but erosion and weeds.
Large: 2 rows, uneven ripeness. Narrow: 1
row.
Vinha ao alto: vertical rows up the slopes,
least expensive.
Madeira Rich, fertile, Warm summer, mild winter. 450 ha. Pergola (latadas), also cordon
volcanic Mountainous. North/centre very wet, trained + spur pruned. High disease
south drier. Humid climate pressure: VSP (espaldeira), leaf removal.
Irrigation by levadas.
VDN Mediterranean, Roussillon warmest. Shady canopy required (sunburn, grape
Tramontane: transpiration: shriveling).
concentration sugar: less spirit
needed, however reduces juice yield.
TIMING OF HARVEST
Botrytis not desirable: harvest before increased risk of rain/humidity. Some styles fruit picked at
just beyond minimum potential alcohol. Unripe fruit flavours avoided, but Sherry from
Palomino, potential alcohol and health grapes much more important than flavours in grapes.
Other styles, such as Rutherglen Muscat, PX and Moscatel Sherry, grapes on vine longer than
full maturity to concentrate sugars, necessary for very high residual sugar.
Sherry 1st week august – 2nd week September. Picked at 12% potential alcohol. Max 80
hl/ha, usually 60-70.
Port Max 55 hl/ha, usually 30.
Madeira Starts end august or early September, by hand. Min 9% abv but no more than 11%
and high acidity. 150 hl/ha (fertile + irrigation).
VDN Max generally 30 hl/ha. Law: min 14.8% abv potential alcohol, usually not riper to
retain acidity. Late harvest not desired.
SKIN CONTACT AND EXTRACTION
Extraction of colour, tannins and flavour from skins key process in red fortifieds: often sweet
and adding fortifying alcohol midway through fermentation process, limiting maceration to 2–3
days. Especially in wines that undergo long ageing (need high concentrations of colour, tannin
and flavours): extraction techniques need to be as effective as possible. Port industry developed
specialist equipment that permit maximum extraction while remaining gentle enough not to
crush seeds and release bitter tannins. Contrast: basic Tawny and Rosé Ports less extraction to
create paler wines. Some producers of Madeira, Muscat-based VDNs and White Port, let white
grapes macerate for limited time on skins, to increase body and texture and extract additional
flavours. By contrast, skin contact not desirable for biologically aged Sherries (Fino, Manzanilla)
as phenolic compounds can restrict growth of flor.
Sherry Pressed on arrival. No skin contact. 1st press more acidity, low phenolics: Fino. 2nd press lower
acidity (potassium from skins), more coarse: Oloroso. Clarify before fermentation: cold settling,
centrifugation, flotation. Cultured yeast 22-26°C, stainless steel. Malo prevented by chilling must
(no SO₂ for flor).
Port Foot treading, modern lagares, pumping over, stainless steel pistons, autovinifiers. Ambient yeast
28-32°C (white 17-22°C, rosé 15-16°C). No malo (bacteria unable to tolerate high alcohol).
Madeira IVBAM checks. Destemmed, crushed, sometimes skin contact. Fined and filtered.
VDN Few hours of skin contact.
Black: fermented + fortified with skins to increase colour, flavour, tannin + pumping over + punching
down to maximise extraction. White 15°C, red 28°C, both to retain fruity aromas.
Rutherglen Grapes partly shriveled: hard to extract juice, therefore fermented briefly on skins to break down
pulp and release sugar and flavours. Enzymes added + cap management techniques.
5
, Iwan Wiering RV, Summary WSET4 D5: Wine Production, 2025-2026
TIMING OF FORTIFICATION
Dry wines: fortified once fermentation is complete, leaving no residual sugar.
Majority of sweet wines: fortifying midway through fermentation, stopping fermentation by
raising alcohol above that at which yeasts can operate, leaving residual sugar. Timing
fortification calculated to desired residual sugar final wine.
Sherries such as Pale Cream, Medium and Cream: fermenting dry, adding sweetening
component: creates different styles than by fortifying during fermentation.
Cream Sherry: dry Oloroso blended with PX, combining characteristics aged, dry Palomino with
raisined PX.
Sherry Base wine 11-12.5%, fortified to 15-15.5% (fino) or 17% (oloroso).
Port Base wine 5-7% and 80-120 g/l sugar, fortified to 19-22%
Madeira Fortified to 17-18%.
VDN White min 100-125 g/l sugar, red min 45 (usually around 100). Base wine 5-8% abv fortified to 15-18%.
Rutherglen Base wine 1-2%: drained off skins + fortified to 17.5%. Light fining for protein stability.
THE FORTIFYING SPIRIT
Sherry 95%. Port 77%. Madeira 96%. VDN 95-96%. Rutherglen Muscat minimal 96%.
Most wines 95–96% abv grape spirit: neutral aroma and flavour, and do not mask characteristics
wine. High level alcohol minimises volume of spirit needed, less dilution base wine. Exception:
Port fortified with grape spirit of 77% abv (+/– 0.5%): more characterful and contributes more of
its own aroma and flavour characteristics to blend. Also due to lower strength, significant
volume of spirit required to bring must to 19–22% abv: style/quality of spirit important influence
on style/quality final wine. Although some producers choose more aromatic styles of spirit (red
Ports), in Rosé Ports relatively subtle spirit not to overpower the delicate style.
In VDN 5-10% is spirit, in Port 25%.
MATURATION
Some fortifieds, including a number of VDNs, Ruby and Rosé Ports and some White Ports,
released early to drink soon after release. Often stored in stainless steel or concrete and
protected from oxygen: youthful, primary flavours.
Other wines released after short ageing with intention to improve in bottle: Vintage, some LBV,
few years in large oak vessels before bottling. Designed to age in bottle: very concentrated with
high tannins on release. After number of years in bottle, fresh fruit develops to dried fruit and
tannins soften and integrate.
Other fortifieds, such as premium Tawny Ports, Madeiras, Rutherglen Muscats and some styles
of VDNs and Sherries, aged oxidatively, often for extended periods. Maturation in small wooden
vessels to encourage oxygen exposure. Small size also increases evaporation rate and leads to
ullage. Choice how often to top-up and whether to fill completely to top as part of managing
exposure to oxygen. Some wines also matured in warm or heated conditions: further speeds up
oxidation, evaporation and general maturation. Oxidative ageing: aromas of almond, hazelnut,
walnut, caramel, toffee, coffee, dried fruits (fig, prune, raisin).
Biological ageing Fino/Manzanilla: aged under veil of flor, protects wine from oxidation, lowering
glycerol (and hence body) and contributing aromas of hay, apple skin, bruised apple, bread
dough, chamomile, almond, hazelnut.
Sherry 600 L butt old American in bodegas 16-20°C and min 65% humidity.
Port Lodges Villanova da Gaia. 600 L pipes to 100,000 L balseiros old oak. Racking to remove lees.
Madeira Estufagem (45-50°C stainless steel) or Canteiro (25-40°C old oak).
6
, Iwan Wiering RV, Summary WSET4 D5: Wine Production, 2025-2026
VDN Unaged or aged (demi-johns, barrels)
Rutherglen Old oak 180-9,000 L, smaller: more evaporation, concentration, oxidation, maturation. Warm, dry
conditions (warehouse: tin roofs): quicker evaporation. Becoming deep brown and tertiary. Non-
vintage: blending for balance, complexity, consistent style.
MADERISATION
Wine heated and oxidised; name from process of maturation used, and has been for a number
of centuries, for wines of Madeira.
RANCIO
Tasting term to describe collection of aromas and flavours some styles of wines: leather, wood
varnish, strong coffee. Origin not well understood, but compounds extracted from wooden
vessels; oxygen and time play a role.
BLENDING
One of most important processes fortified wine production. Grapes, must or wines from
different varieties, vintages and vineyard sites all blended, depending on regulations, as well as
wines handled differently in winery.
Key aims blending:
Balance
Components that need balancing differ depending on style of wine. All fortifieds: alcohol
relatively high (compared to unfortified wines) and therefore in wines of good quality and above,
should be integrated within other components. Wines that undergo long ageing become
increasingly concentrated and lose primary fruit characters. Although these wines are complex,
better balance in final wine usually achieved by blending some younger wines with the older
wines: degree of freshness against developed flavours. Particularly notable in Sherry and
Rutherglen Muscat.
Balance – wines are generally aged for long periods of time and will be blended with younger
wines before bottling, to give a degree of freshness to the wine by balancing out the developed
aromas and flavours.
Consistency
Many fortifieds are non-vintage, expected to show consistency year on year. In some regions,
wines of different vintages mature separately (static maturation). Skilled blenders taste wines
from different vintages and create blend. In Sherry solera: fractional blending ensures
consistency among vessels of particular age. Modified version solera for Rutherglen Muscat.
Consistency – as many wines are non-vintage, wines from each vintage are matured individually,
blending from many vintages are needed to create a consistent product year on year.
Style
Blending essential method of influencing style. Port: blend of varieties important for level of
colour, tannin and flavour concentration in young wine and therefore ability to age.
Sweetened Sherries: blending in sweetening component, such as PX wine, completely
transforms style final wine. Brands important in most fortified wine categories: blending to
create ‘house style’ across the product range.
Style – blending influences the style of wine, for example, the choice of grape varieties used in
Port production will impact on colour, tannin and flavour concentration. This influences the
wine's ability to age or not. In some styles of Sherry, a sweetening component is added to the
final wine to create a sweet style of wine.
Complexity
Wines of different ages or have been treated differently in winery blended to gain greater range
of flavours.
7
WSET4: D5
FORTIFIED WINES
Iwan Wiering RV, 2025-2026
www.wijnlerendrinken.nl
, Iwan Wiering RV, Summary WSET4 D5: Wine Production, 2025-2026
Summary WSET4
D5 Fortified Wines
Iwan Wiering:
I am a Dutch wine teacher, music teacher and conductor. In 2020 I graduated WSET3. In 2021 I
aced all 4 exams (3 theory modules and 1 tasting module) at the Dutch Wine Academy in 1 day,
becoming “Registervinoloog van de Wijnacademie”. In 2023 I started studying for the WSET4
Diploma. I hope this summary will help you ace your D5 exam, as it helped myself to get
prepared for the exam.
In the last few years I gathered many digital maps. Please check www.wijnlerendrinken.nl for
more information on how to take advantage on them on a small cost.
Please use a licensed purchased copy of this summary only, since I put a lot of time and effort in
writing it. Diploma Course will cost you around Euro 10.000,00 at least. Please don’t economize
for the last few Euros, but let me be of a little profit instead. This way I can keep on writing many
documents and summaries to your advantage, and keep them updated.
As WSET stimulates ‘talking around the subject’ and ‘flair’ to gain higher marks, I added some
useful extra info from the ‘Sherry Academy’ and the ‘School of Port’ in this summary, that
doesn’t show in the textbook but might help you to a higher percentage.
Please also check some useful podcasts on https://eatsleepwinerepeat.co.uk/podcasts/ as
they can be very helpful.
Cheers and thanks, Iwan.
2
, Iwan Wiering RV, Summary WSET4 D5: Wine Production, 2025-2026
List of Abbreviations
DO Denominación de Origen
IVBAM Instituto do Vinho, do Bordado e do Artesanato da Madeira
IVDP Instituto dos Vinhos do Porto e do Douro
IVP Instituto do Vinho do Porto
LBV late bottled vintage
PDO Protected Denomination of Origin
PGI Protected Geographical Indication
PX Pedro Ximénez
RCGM rectified concentrated grape must
SAT Systematic Approach to Tasting
VDN Vins Doux Naturels
VOS Vinum Optimum Signatum / Very Old Sherry
VORS Vinum Optimum Rare Signatum / Very Old Rare Sherry
VSP vertical shoot position
VVO very very old
3
, Iwan Wiering RV, Summary WSET4 D5: Wine Production, 2025-2026
1: Key Choices Affecting Style, Quality
and Price in Fortified Wines
Learning Objectives:
1. Describe the process of fortification.
2. Explain how maturation options impact on the style, quality and price of fortified wines.
3. Explain how winemaking and post-fermentation options impact on the style, quality and price of
fortified wines.
Red, white, rosé; dry to sweet; youthful and aromatic to fully developed and oxidative.
GRAPE VARIETY
May provide own aroma/flavour to wine (VDNs from Muscat, protective winemaking, early
release) or be simply used as neutral base for flavours of maturation.
Rutherglen Muscat (wines aged in warm, oxidative conditions), aromas Muscat still noticeable
in best wines.
Palomino (neutral variety): Sherry aromas from maturation process. Combination bone-dry
palate, low glycerol, pungency from high acetaldehyde can give sensation similar to acidity in
Fino and Manzanilla, but acidity is low (characteristic of Palomino).
Structural components (acidity and, in black grapes, colour and tannin) important factors.
Madeira (notable for high acidity) number of varieties, such as Sercial and Verdelho, with
naturally high acidity.
Colour important consideration in red wines. Port usually blend, attaining suitable level of
colour in base wine. Basic Tawny Port needs to look aged in short time: made from wines that
are light in colour compared to Vintage Port (expected to retain deep colour over decades of
bottle maturation, includes Touriga Nacional and Sousão).
Influence tannin: high levels not required nor desirable in early drinking styles of Ruby Port or
Maury Grenat. By comparison, role of tannins in colour stability makes medium (+) or high levels
beneficial in long-aged wines. Tannins soften with age, and can become integrated and provide
necessary structure and balance on palate.
VINEYARD SITE
Vineyard location and climate important influences on base material fortifieds. Douro vineyards
scored according to location, aspect, altitude: determines how much Port wine plot can
produce. Vintage Ports come from plots known to produce outstanding-quality wines that age
well. Languedoc Muscat de Frontignan: slightly fuller wines with riper flavours from low altitude
vineyards than high-altitude sites Muscat de St-Jean-de-Minervois.
Region Soil Climate Vineyards
Sherry Albariza: limestone, 36° North, 0-90 m. Hot mediterranean 7,000 ha. Cordon trained + spur pruned,
silica, clay with hot, dry summers and mild VSP: open canopy, mechanisation, reduces
(Palomino) relatively warm winters, no frost. disease pressure. Gentle 10–15% slopes.
Barros: more clay Poniente – Levante. Challenge: Albariza crusts. Troughs/gullies catch winter
Arenas: sandy sunburn. Low disease pressure, but rain: aserpia.
(Moscatel) mildew, European grapevine moth
(pheromone traps).
Port Stony, shallow, free- Warm continental: hot summers, cold 32,000 ha. Steep slopes. Cordon trained +
draining, poor. winters. Shelter from Serra do Marão: spur pruned or head trained + cane pruned.
Schist splits in warmer and drier than Porto. VSP, summer pruning, fertilisers.
4
, Iwan Wiering RV, Summary WSET4 D5: Wine Production, 2025-2026
vertical layers: deep Baixo Corgo (west, wettest), Cima Socalcos: trad narrow terraces supported
rooting Corgo, Douro Superior (east, driest). by walls of dry rock.
Patamares: terraces supported by steep
earth ramp, cheaper but erosion and weeds.
Large: 2 rows, uneven ripeness. Narrow: 1
row.
Vinha ao alto: vertical rows up the slopes,
least expensive.
Madeira Rich, fertile, Warm summer, mild winter. 450 ha. Pergola (latadas), also cordon
volcanic Mountainous. North/centre very wet, trained + spur pruned. High disease
south drier. Humid climate pressure: VSP (espaldeira), leaf removal.
Irrigation by levadas.
VDN Mediterranean, Roussillon warmest. Shady canopy required (sunburn, grape
Tramontane: transpiration: shriveling).
concentration sugar: less spirit
needed, however reduces juice yield.
TIMING OF HARVEST
Botrytis not desirable: harvest before increased risk of rain/humidity. Some styles fruit picked at
just beyond minimum potential alcohol. Unripe fruit flavours avoided, but Sherry from
Palomino, potential alcohol and health grapes much more important than flavours in grapes.
Other styles, such as Rutherglen Muscat, PX and Moscatel Sherry, grapes on vine longer than
full maturity to concentrate sugars, necessary for very high residual sugar.
Sherry 1st week august – 2nd week September. Picked at 12% potential alcohol. Max 80
hl/ha, usually 60-70.
Port Max 55 hl/ha, usually 30.
Madeira Starts end august or early September, by hand. Min 9% abv but no more than 11%
and high acidity. 150 hl/ha (fertile + irrigation).
VDN Max generally 30 hl/ha. Law: min 14.8% abv potential alcohol, usually not riper to
retain acidity. Late harvest not desired.
SKIN CONTACT AND EXTRACTION
Extraction of colour, tannins and flavour from skins key process in red fortifieds: often sweet
and adding fortifying alcohol midway through fermentation process, limiting maceration to 2–3
days. Especially in wines that undergo long ageing (need high concentrations of colour, tannin
and flavours): extraction techniques need to be as effective as possible. Port industry developed
specialist equipment that permit maximum extraction while remaining gentle enough not to
crush seeds and release bitter tannins. Contrast: basic Tawny and Rosé Ports less extraction to
create paler wines. Some producers of Madeira, Muscat-based VDNs and White Port, let white
grapes macerate for limited time on skins, to increase body and texture and extract additional
flavours. By contrast, skin contact not desirable for biologically aged Sherries (Fino, Manzanilla)
as phenolic compounds can restrict growth of flor.
Sherry Pressed on arrival. No skin contact. 1st press more acidity, low phenolics: Fino. 2nd press lower
acidity (potassium from skins), more coarse: Oloroso. Clarify before fermentation: cold settling,
centrifugation, flotation. Cultured yeast 22-26°C, stainless steel. Malo prevented by chilling must
(no SO₂ for flor).
Port Foot treading, modern lagares, pumping over, stainless steel pistons, autovinifiers. Ambient yeast
28-32°C (white 17-22°C, rosé 15-16°C). No malo (bacteria unable to tolerate high alcohol).
Madeira IVBAM checks. Destemmed, crushed, sometimes skin contact. Fined and filtered.
VDN Few hours of skin contact.
Black: fermented + fortified with skins to increase colour, flavour, tannin + pumping over + punching
down to maximise extraction. White 15°C, red 28°C, both to retain fruity aromas.
Rutherglen Grapes partly shriveled: hard to extract juice, therefore fermented briefly on skins to break down
pulp and release sugar and flavours. Enzymes added + cap management techniques.
5
, Iwan Wiering RV, Summary WSET4 D5: Wine Production, 2025-2026
TIMING OF FORTIFICATION
Dry wines: fortified once fermentation is complete, leaving no residual sugar.
Majority of sweet wines: fortifying midway through fermentation, stopping fermentation by
raising alcohol above that at which yeasts can operate, leaving residual sugar. Timing
fortification calculated to desired residual sugar final wine.
Sherries such as Pale Cream, Medium and Cream: fermenting dry, adding sweetening
component: creates different styles than by fortifying during fermentation.
Cream Sherry: dry Oloroso blended with PX, combining characteristics aged, dry Palomino with
raisined PX.
Sherry Base wine 11-12.5%, fortified to 15-15.5% (fino) or 17% (oloroso).
Port Base wine 5-7% and 80-120 g/l sugar, fortified to 19-22%
Madeira Fortified to 17-18%.
VDN White min 100-125 g/l sugar, red min 45 (usually around 100). Base wine 5-8% abv fortified to 15-18%.
Rutherglen Base wine 1-2%: drained off skins + fortified to 17.5%. Light fining for protein stability.
THE FORTIFYING SPIRIT
Sherry 95%. Port 77%. Madeira 96%. VDN 95-96%. Rutherglen Muscat minimal 96%.
Most wines 95–96% abv grape spirit: neutral aroma and flavour, and do not mask characteristics
wine. High level alcohol minimises volume of spirit needed, less dilution base wine. Exception:
Port fortified with grape spirit of 77% abv (+/– 0.5%): more characterful and contributes more of
its own aroma and flavour characteristics to blend. Also due to lower strength, significant
volume of spirit required to bring must to 19–22% abv: style/quality of spirit important influence
on style/quality final wine. Although some producers choose more aromatic styles of spirit (red
Ports), in Rosé Ports relatively subtle spirit not to overpower the delicate style.
In VDN 5-10% is spirit, in Port 25%.
MATURATION
Some fortifieds, including a number of VDNs, Ruby and Rosé Ports and some White Ports,
released early to drink soon after release. Often stored in stainless steel or concrete and
protected from oxygen: youthful, primary flavours.
Other wines released after short ageing with intention to improve in bottle: Vintage, some LBV,
few years in large oak vessels before bottling. Designed to age in bottle: very concentrated with
high tannins on release. After number of years in bottle, fresh fruit develops to dried fruit and
tannins soften and integrate.
Other fortifieds, such as premium Tawny Ports, Madeiras, Rutherglen Muscats and some styles
of VDNs and Sherries, aged oxidatively, often for extended periods. Maturation in small wooden
vessels to encourage oxygen exposure. Small size also increases evaporation rate and leads to
ullage. Choice how often to top-up and whether to fill completely to top as part of managing
exposure to oxygen. Some wines also matured in warm or heated conditions: further speeds up
oxidation, evaporation and general maturation. Oxidative ageing: aromas of almond, hazelnut,
walnut, caramel, toffee, coffee, dried fruits (fig, prune, raisin).
Biological ageing Fino/Manzanilla: aged under veil of flor, protects wine from oxidation, lowering
glycerol (and hence body) and contributing aromas of hay, apple skin, bruised apple, bread
dough, chamomile, almond, hazelnut.
Sherry 600 L butt old American in bodegas 16-20°C and min 65% humidity.
Port Lodges Villanova da Gaia. 600 L pipes to 100,000 L balseiros old oak. Racking to remove lees.
Madeira Estufagem (45-50°C stainless steel) or Canteiro (25-40°C old oak).
6
, Iwan Wiering RV, Summary WSET4 D5: Wine Production, 2025-2026
VDN Unaged or aged (demi-johns, barrels)
Rutherglen Old oak 180-9,000 L, smaller: more evaporation, concentration, oxidation, maturation. Warm, dry
conditions (warehouse: tin roofs): quicker evaporation. Becoming deep brown and tertiary. Non-
vintage: blending for balance, complexity, consistent style.
MADERISATION
Wine heated and oxidised; name from process of maturation used, and has been for a number
of centuries, for wines of Madeira.
RANCIO
Tasting term to describe collection of aromas and flavours some styles of wines: leather, wood
varnish, strong coffee. Origin not well understood, but compounds extracted from wooden
vessels; oxygen and time play a role.
BLENDING
One of most important processes fortified wine production. Grapes, must or wines from
different varieties, vintages and vineyard sites all blended, depending on regulations, as well as
wines handled differently in winery.
Key aims blending:
Balance
Components that need balancing differ depending on style of wine. All fortifieds: alcohol
relatively high (compared to unfortified wines) and therefore in wines of good quality and above,
should be integrated within other components. Wines that undergo long ageing become
increasingly concentrated and lose primary fruit characters. Although these wines are complex,
better balance in final wine usually achieved by blending some younger wines with the older
wines: degree of freshness against developed flavours. Particularly notable in Sherry and
Rutherglen Muscat.
Balance – wines are generally aged for long periods of time and will be blended with younger
wines before bottling, to give a degree of freshness to the wine by balancing out the developed
aromas and flavours.
Consistency
Many fortifieds are non-vintage, expected to show consistency year on year. In some regions,
wines of different vintages mature separately (static maturation). Skilled blenders taste wines
from different vintages and create blend. In Sherry solera: fractional blending ensures
consistency among vessels of particular age. Modified version solera for Rutherglen Muscat.
Consistency – as many wines are non-vintage, wines from each vintage are matured individually,
blending from many vintages are needed to create a consistent product year on year.
Style
Blending essential method of influencing style. Port: blend of varieties important for level of
colour, tannin and flavour concentration in young wine and therefore ability to age.
Sweetened Sherries: blending in sweetening component, such as PX wine, completely
transforms style final wine. Brands important in most fortified wine categories: blending to
create ‘house style’ across the product range.
Style – blending influences the style of wine, for example, the choice of grape varieties used in
Port production will impact on colour, tannin and flavour concentration. This influences the
wine's ability to age or not. In some styles of Sherry, a sweetening component is added to the
final wine to create a sweet style of wine.
Complexity
Wines of different ages or have been treated differently in winery blended to gain greater range
of flavours.
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