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
