18.3 Whole Berry/Bunch Fermentations Flashcards
If whole bunches are used in fermentation, how must the grapes have been harvested?
Hand-harvested
What are the two options for using uncrushed fruit in fermentation?
- whole bunches of grapes
2. whole destemmed grapes
If using whole bunches of grapes are used, what is very important? Why?
- stems of the bunches must be fully ripe
- unripe stems can add unpleasant green flavours and bitter tannins
What desirable flavours can stems add?
- ‘spicy’ or ‘herbal’
- can also add some tannins
What might producers do to crushed fruit fermentations to add ‘spicy’ or ‘herbal’ flavours?
add left over stems from the destemming process
Why might a producer specifically choose not to add stems?
- when fermenting grape varieties with naturally high tannins
- e.g. Cabernet Sauvignon
What is the objective of whole berry/bunch fermentation?
- to create an oxygen free environment for the uncrushed fruit
What are the outcomes of an oxygen-free fermentation of whole berries/bunches?
- grapes change from aerobic respiration to anaerobic metabolism
- some sugar is converted to alcohol (without yeast)
- malic acid broken down to create ethanol (reducing malic acid by 50%, lowering acidity, raising pH)
- glycerol levels increase (add texture)
- distinctive aromas created inside the grape (kirsch, banana, bubble gum and cinnamon)
What is intracellular fermentation?
- grapes change from aerobic respiration to anaerobic metabolism
- some sugar is converted to alcohol without the involvement of any yeast
What flavors are the result of whole berry/bunch fermentation?
kirsch, banana, bubble gum, cinnamon
What are the costs associated with whole berry/bunch fermentation?
- techniques do not have a significant impact on cost
- hand-harvesting, sorting, use of oak will all add costs
What are the 3 forms of whole berry/bunch fermentation?
- Carbonic Maceration
- Semi-Carbonic Maceration
- Whole Berries/Bunches w/ Crushed Fruit
What is carbonic maceration?
- only whole, uncrushed bunches used
- vessels filled with CO2 to remove all oxygen
- intracellular fermentation starts
- alcohol level in grape reaches ~2%
- grapes skins split, juice released
- juice drained
- grapes pressed
- free run juice + press juiced blended
- fermentation completes
When do the grape skins start to split in carbonic maceration?
When the alcohol level in grape reached ~2%
What does carbonic maceration extract from the grapes? What does it barely extract?
- Extracts colour
- Barely extracts any tannins
Describe a wine that has gone through carbonic maceration.
- fruity
- low tannins
- not super complex
- distinctive notes of kirsch, banana, bubble gum and cinnamon-like spice
- fruit notes from the grape variety
- unlikely to use oak
When are wines that go through carbonic maceration best consumed?
within a year after harvest
What quality wines are typically made with carbonic maceration?
acceptable or good, inexpensive and mid-priced wine
Name a region and a type of wine that are famous for carbonic maceration.
- Beaujolais
- Beaujolais Nouveau
What is semi-carbonic maceration? How is it different from carbonic maceration?
- does not involve filling the vessel with CO2
- start with whole bunches
- bottom grapes crushed under the weight of the grapes above
- some juice released
- ambient yeast start to ferment the juice (cultured yeast can also be added)
- fermentation produces CO2, which fills the vessel
- remaining intact grapes undergo carbonic maceration
- intact grapes begin to split
- release their juice
- grapes are pressed
- yeast complete the fermentation off skins
How might a producer use semi-carbonic maceration but also create a wine with slightly more concentration, body and tannin, and hence a longer ageing capacity?
- Continue the alcoholic fermentation on the skins
- Punching down or pumping over
- Ever-decreasing amount of carbonic maceration takes place
- Post-fermentation maceration and/or maturation in oak
When fermentation is continued on the skins post semi-carbonic maceration, what does it add to the wine?
- better integration of the aromas from intracellular fermentation with aromas from the grape variety
- more fruitiness
- softer mouthfeel
How is whole berry/bunch with crushed fruit fermentation carried out?
- not blanketed in CO2
- whole berries/bunches largely submerged by crushed grapes
- kept away from oxygen
- intracellular fermentation takes place
- berries crushed
- cap regularly punched down
What are the effects of whole berry/bunch with crushed fruit fermentation on the end wines?
- smoother texture
- more vibrant and fresh primary aromas (than crushed fruit fermentations)
What styles and qualities of wines is whole berry/bunch with crushed fruit fermentation used on?
- wide range of grape varieties
- wines of different qualities and prices
