2 - Port Winemaking Flashcards
Fermentation
- In port production the fermentation is stopped by the addition of grape spirit
- creating a sweet wine with usually 80-120g/L residual sugar
maceration
- maceration with the skin last for a maximum of two day
- extraction technique is very effective
Key methods of extraction during the fermentation
- foot treading in lagares
- modern lagares
- pumping over
- stainless-steel pistons
- autovinifiers
Foot treading in lagares
Small number of premium and super-premium ports used
- lagar is shallow around 80cm deep square tank
- allowing a large surface ate between the must and the grapes skins
- traditionally they were made from granite
- the extraction would come from foot treading
- foot treading is effective at extracting but the same time gentle enough not to crush the seeds
Modern lagares / robotic lagares
- silicon feet’s
- attached to a stainless-steel gantry
- press the grapes against the lagares floor and subsequently punch down the cap
- initial investment for the equipment is high
-modern lagares can produce wines of equal to those produce by foot treading
Pumping over
- this technique can produce ports with deep colour and high levels of concentration
- is not as effective at extracting as foot treading or modern lagares
Stainless-steel pistons
- open stainless-steel vats with the pistons punch done the cap to a programmed schedule
- can be used in conjunction with pumping over
- usually needed to promote a more-even extraction
- produce wines very similar in quality as modern lagares or foot treading
autovinifiers
- sealed concrete or stainless-steel tanks
- provide a solution to cap management
- little extraction occurs before fermentation starts
- does not require electricity
- rising pressure of the CO2 produce from the fermentation pushes the juice up through pipes into a holding tank
- the pressure of the CO2 reaches a certain level the value automatically released and the wine in the holding tank is no longer supported by the gas pressure sprays over the cap
- wines light colour, body and flavours
- suitable for basic tawny, white and ruby ports
Fermentation vessels
- stainless-steel easy to control temperature and clean
- small volume can use granite, concrete and old wood
destemmed
-unripe stems can impart bitterness
-fully ripe stems can aid pressing
reducing compaction
drainage
fermentation temperature
Red port 28-32c
White port 20c
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Fortification
fortified to an alcohol strength between 19-22%abv
-aguardente or spirit used for the fortify must come from grapes or grape derived about 77%abv
- the reason of port displays spirity aromas because the low abv distillation
- the other reason is the amount of spirit 1L spirit for 4L fermented must
- because of this the quality the spirit need be good
- since 1991 producers start sourcing and buying their own aguardente improving quality
- fermentation is stoped around 5-7%abv
- sugar levels at 80-120%abv depending the house style
-the grapes for port are picked when the flavours and tannins are ripe potential alcohol is not an issue for these wines acidity can be low and ph high acidification is common
-the wine is drained from the skins before adding the aguardente
- the mass of the grapes skins after draining will be pressed
- the pressed wine will be add to the free run wine to provide greater colour and tannins
- necessary of wines that are to undergo long periods of ageing
- ports do not go trough malolactic conversion
- all the ports spend there first winter in the Douro
- after fermentation wines are left to clarify before rack
- rotary vacuum filter are used to remove the remaining lees
- in the spring wines may be shipped to the lodges in Vila nova de Gaia
blending is a key part of the production process and may happen at any point
-blends from different vineyard parcels
-different grapes varieties
(co-fermentation of different varieties is quite common)
- depending on the style different vintages
- lots are treated differently in the winery may also be kept separate and used as blending options
- wines destined to vintage port will have deeper colour, greater concentration of flavours, high tannins to be able to undergo extensive ageing
maturation
- climate of Vila Nova de Gaia is better suited to the maturation of port wine
(strong Atlantic influence the temperature are generally cooler and mor constant - however in recent times gradually more producers have build well-insulated, humidity-controlled lodges in the vineyard are
- most styles of port aged in oak even if is for a short time
- balseiros are vats with 100.000 L generally used to store wines and keep them fresh
- pipes 600L generally used to gentle oxidation
-for port maturation don’t want new oak flavours only used barrels are used for port ageing
Racking
- carried out during the maturation process to remove lees
- control the amount of oxidation as is the degree to which the vessels are topped up with wine
