Standard Winemaking Options Flashcards
After how many months do autolytic notes start to become evident?
15-18 months
What factors affect the length of lees aging?
Desired style (primary fruit vs Lees)
Final price that can be attained
Financial ability to invest in storage
In what vessel does primary fermentation normally take place and why?
Stainless steel:
- large volumes can be fermented at one time
- temperature control
- easy to clean before and after fermentation
Why is second fermentation stressful for yeast?
- alcoholic conditions (10% too high for many)
- low pH
- low temperature
- high pressure
- poor availability of nutrients
What are the most popular types of press?
Pneumatic and traditional basket press
Why are cultured yeasts typically used in sparkling winemaking?
The priority is a reliable, healthy ferment - yeasts must be able to reliably ferment to dryness in challenging conditions with high acid and low pH.
Yeasts can be choose to emphasise a particular character in the wine - e.g. a neutral yeast will be used for autolytic styles so as to not emphasise fruity flavours which will compete with autolysis
Rapid autolysis and easy flocculation also often desirable
What is another name for second fermentation?
Prise de mousse (capturing the sparkle)
Why is whole bunch pressing a popular choice for premium traditional method sparkling wines?
- One of the gentlest forms of pressing.
- Gives delicate juice that is low in solids and phenolics (including tannin and anthocyanin)
- Stems create a network of channels that the juice can flow through more easily - minimises the press pressure required
What process can help remove excessive tannin and colour before primary fermentation?
Fining with casein, gelatine etc
Why is a steady temperature important for second fermentation?
Maintain yeast viability
Why would malolactic conversion be used?
Reduce acidity
Enhance texture
If malo is not desirable, wine may be sterile filtered
What qualities are desirable in a yeast for second fermentation?
Can commence ferment at 9-11% alcohol
Can cope with moderate temperature
Can cope with low pH
Can withstand high pressure
Can flocculate readily and easily to create a coarse sediment
What are the purposes of blending?
- Balance
- Consistency
- Style (house, early drinking)
- Rosé
- Complexity
- Minimise faults
- Volume
- Price
How does temperature affect the length of second fermentation sur latte?
Cooler temperatures create a longer, slower fermentation. This is said to create a more complex finished wine
What are the options available for base wine pre-second fermentation?
- maturation in oak
- Lees aging
What are the characteristics of press fractions (not free run juice)?
Press fractions are higher in phenolics, solids and pH and are useful for blending options.
The juice matures more quickly due to the higher level of solids, so can be good for wines with short maturation intended for early consumption
What is the pressure considered appropriate for most sparkling wines?
Six atmospheres/bars
What is a typical temperature for first fermentation and why?
14-20 degrees. Cooler temperatures help to retain primary fruit flavours
What does the liqueur de tirage contain?
Sugar (amount depends on desired level of effervescence)
Yeast
Yeast nutrients
Clarifying agent (such as bentonite or alginate)
What is autolysis?
The enzymatic breakdown of dead yeast cells
How long does autolysis continue?
On average 4-5 years, has been known to last up to 10
What are pupitres used for?
Hand riddling (remuage)
Describe the process of riddling (remuage)
Steady slow inclination towards the neck of the bottle causes the yeast to flocculate and fall towards the neck of the bottle
What effect does cooling the neck of the bottle have during disgorgement?
Frozen brine eases extraction, makes sure the yeast does not fall back into the bottle and increases the solubility of CO2 so the wine is less likely to gush
What is in the liqueur d’expedition?
A mixture of wine and sugar (or RCGM)
What is the role of dosage?
Added in the liqueur d’expedition to determine the final sweetness in the wine.
Used to balance acidity and encourage the development of post-disgorgement aromas via the Maillard reaction
What is the Maillard reaction?
The sugar in the liqueur d’expedition (dosage) reacts with compounds formed during yeast autolysis and roasted, toasted vanilla aromas develop
Describe the different between the traditional method and the transfer method
In transfer, riddling does not take place. Instead the wine is chilled to 0c.
Bottles are opened, the wine is poured into a pressurised tank. It is sweetened, sterile filtered, SO2 added and then rebottled.
What is the purpose of transfer method?
To avoid the cost of manual riddling without losing biscuity autolytic notes in the final wine
Why is transfer method less common now?
Developments in riddling technology (gyropalettes) mean that the key advantage of the method has been lost
Which formats still commonly use the transfer method?
Quarter bottles and Jeroboam sizes and larger - these formats are all v difficult to riddle
Describe the Ancestral method
Partly fermented must is placed into bottles. The remaining sugar is converted into alcohol and CO2, creating effervescence
What is another name for the Ancestral method?
Pet Nat (petillant nature)
What are the characteristics of a pet Nat wine?
Low alcohol, slightly cloudy (sediment is rarely removed) dry to off dry, unconventional flavours reminiscent of cider, early drinking (often bottled without additional SO2)
What other names is the tank method known by?
Cuvé Close, Charmat, Martinotti
What are the benefits of the tank method?
- Large volumes made inexpensively and quickly
- Much less labour intensive than traditional method
- Straightforward - no additional processes (such as riddling) or time on lees
What grape varieties are best suited to the tank method and why?
Semi aromatic - Glera - or aromatic - Muscat
The process preserves fresh fruity flavours
How and why is fermentation stopped during tank method?
Wine is cooled to around -5c when desired levels of pressure and residual sugar have been reached
Why is a cool first fermentation important for tank method?
Preserves fruity and floral flavours and aromas
Why is tank method wine cold stabilised after second fermentation?
To precipitate tartrates
How is tank method wine bottled?
With a counter pressure filler. Bottle is filled with CO2 under pressure then chilled wine replaces the CO2. This prevents oxygen entry and loss of CO2
Describe the Asti method
Must fermented in pressure tanks - CO2 allowed to escape until the wine has reached around 6% alcohol then the tank is closed.
CO2 is generated from the remaining sugar and another 1.5% alcohol is generated
Why are yeasts removed from wines such as Asti?
To ensure that it is stable despite a high level of fermentable sugar
What are the advantages of carbonation?
Quick
Easy
Leaves aromas and flavours of the base wine intact
What are the disadvantages of carbonation?
Bubbles may die quickly
Effervescence may highlight off flavours in lesser quality base wine
What level of residual sugar does a Brut wine have? (EU standard)
0-12g/l
What is the level of residual sugar in an extra dry wine (EU regs)?
12 - 17 g/l
How much residual sugar does a Brut Nature wine have? (EU regs)
0 - 3 g/l
What factors affect the mousse?
- Sugar availability. The more sugar the more CO2
- Capacity of CO2 to dissolve. Depends on health of grapes and winemaking process
- time on lees
- Efficiency of disgorgement
- Time in bottle
- Type of closure
- Service = temperature, glass shape etc
Describe the character of the mousse in wines that have not had long lees aging
Lively but short lived
