Red: Whole Berry and Bunch Fermentation

Question 1

What are the three methods of whole fruit fermentation?

Answer 1

1. carbonic maceration
2. semi-carbonic maceration
3. whole bunches and berries with crushed fruit

Question 2

Why is it important to have “ripe” stems when using whole bunches?

Answer 2

• ripe stems give pleasant flavors and tannins to the fermentation when whole bunches are used
• unripe stems give unpleasant flavors and bitter tannins

Question 3

What is the objective of using whole bunches or berries during fermentation?

Answer 3

• objective is to create an oxygen-free environment for the uncrushed fruit, which causes the grapes to change to anaerobic metabolism
• some of the sugar in the grape is converted into alcohol
• malic acid is broken down to create alcohol, which lowers the acidity and pH, and glycerol levels increase, which adds texture
• distinctive aromas are created, which include kirsch, banana, bubblegum, and cinnamon

Question 4

Describe the carbonic maceration process.

Answer 4

• whole, uncrushed bunches are placed into vessels that are filled with CO2
• intracellular fermentation starts, producing above 2% abv
• the grapes are crushed or burst
• juice is normally drained, and grapes are pressed
• yeast completes fermentation

Question 5

What style of wines does carbonic maceration result in?

Answer 5

• red wine with bright color, low tannin
• flavors of kirsch, banana, bubblegum, etc.
• best consumed while young
• often used for Bojo Nouveau

Question 6

Describe the process of semi-carbonic maceration.

Answer 6

• the vessel is filled with whole bunches
• the weight of the grapes crushes fruit at the bottom
• ambient yeast starts fermentation of the juice, producing CO2
• CO2 fills the vessel and the intact grapes undergo carbonic maceration
• the grapes split
• the grapes are pressed and complete a conventional fermentation

Question 7

How can a winemaker use semi-carbonic maceration, but produce a wine with more concentration, body, and tannins?

Answer 7

• perform alcoholic fermentation in contact with the skins, followed by post-fermentation maceration and maceration in oak
• this is sometimes done when making fruity styles of wines from Pinot Noir, Malbec, Tempranillo, Gamay, and Carignan

Question 8

Describe the method of mixing whole berries and bunches with crushed fruit.

Answer 8

• whole bunches or berries are mixed with crushed fruit during the fermentation
• as the whole fruit is submerged in liquid, it is kept away from oxygen and goes through intracellular fermentation
• punching down crushes more and more fruit
• post-fermentation maceration and oak maturation may follow

Question 9

What are the goals of mixing whole fruit with crushed fruit for fermentation?

Answer 9

• to give a smoother texture to the wine
• to give more vibrant and fresh primary aromas