D1C16 White Winemaking

Question 1

What are orange wines?

Answer 1

White wines fermented on skins without temperature control/sulphur additions

Question 2

What are the benefits of whole bunch pressing in white winemaking?

Answer 2

• reduces chance of oxidation before/during the process
• gentlest form of pressing
• however, only an option if grapes have been hand-picked

Question 3

What is free run juice?

Answer 3

Juice drained off as soon as grapes are crushed (lowest in tannin and colour)

Question 4

What is press juice?

Answer 4

Wine that runs off through pressing (lower acidity and less sugar than free run)

Question 5

What are press fractions?

Answer 5

Separate fractions of press juice that may later be blended together in winemaking/maturation process

Question 6

What is hyperoxidation?

Answer 6

• a process of deliberately exposing the must to large quantities of oxygen before fermentation
• targets compounds in the must that oxidize most readily turning them brown, then during fermentation they precipitate, turning wine to original colour
• aim is to produce wines that are more stable against oxygen after fermentation
• more suited to neutral varieties (ex. Chardonnay)

Question 7

What are four methods to clarify white wine must?

Answer 7

1) sedimentation
2) flotation
3) centrifugation
4) clarifying agents

Question 8

What is sedimentation?

Answer 8

• simplest (and cheapest) method of clarifying must (and wine) where must is chilled to around 4 degrees C, and suspended solids are left to fall over time (12-24 hours)
• clear juice is racked into fermentation vessel

Question 9

What is flotation?

Answer 9

• a must clarification method that involves bubbling gas (usually nitrogen) up through must
• as bubbles rise, they bring the solid particles with them which are then skimmed off top of vessel
• fining agents must be added for particles to bind together
• can be continuously done and must doesn’t have to be chilled

Question 10

What is a centrifuge (and centrifugation)?

Answer 10

• a machine that comprises of a rapidly rotating container which uses centrifugal force to separate solids from liquids
• used continuously, works quickly, but expensive
• can be used on must and wine

Question 11

What are fermentation temperatures for white wines?

Answer 11

• 15 degrees C if fruity aromas are desired

- 27-25 if fruity aromas aren’t desired, to promote yeast health

Question 12

What do different fermentation vessels do for white wines?

Answer 12

• stainless steel: fruity, floral whites during to ability to control temperature easily
• concrete and oak: may be used for wines at warmer temperatures where fruity/floral aromas aren’t the aim
• smaller oak vessels becoming more popular (especially in premium Chardonnay) due to deeper, fuller body (oxidative environment)

Question 13

What are the effects of MLF on white wines? (4)

Answer 13

1) reduction in acidity
2) increase in pH
3) increase in microbiological stability
4) modification to flavour

Question 14

What are the steps for maturation, finishing and packaging white wine?

Answer 14

newly made wine –> blending? –> maturation in oak vessels? –> lees aging? –> blending? –> stabilization –> clarifying? –> packaging –> wine for sale

Question 15

What affects does lees aging have on white wine?

Answer 15

• gives more body, softens mouthfeel, helps stabilize

- protects wine from oxygen