16.5 Fermentation Temperatures and Vessels for White Wine

Question 1

Why is 15°c an ideal temperature for fermenting white grape must?

Answer 1

Desirable volatile aroma and flavour compounds such as esters are best produced and retained at cooler temperatures.

Question 2

When are fruity aromas not desired in white wine?

Answer 2

When a winemaker wants oak to provide aroma and flavour.

Question 3

If a winemaker wants less fruity aromas, at what temperature might she ferment white grape must?

Answer 3

17-25°c, usually in the middle of this range (20°c).

Question 4

What ester is not produced when white grape is fermented between 17-25°c?

Answer 4

Isoamyl acetate (banana-like aroma)

Question 5

Stainless steel vessels are used for making what style of white wine?

Answer 5

Fruity and floral white wines such as Sauvignon Blanc and Pinot Grigio from Veneto.

Question 6

Name 2 reasons why stainless steel vessels are used for making floral and fruity white wines.

Answer 6

1) Easy to control temperatures and maintain a cool fermentation which enhances these aromas

2) Stainless steel is an inert vessel which stops oxygen ingress which can destroy volatile aromas

Question 7

What vessels are used to ferment white grape must at higher temperatures?

Answer 7

Concrete, old oak, as well as stainless steel

Question 8

Why would a winemaker ferment white grape must at higher temperatures (i.e., between 17-25°c)?

Answer 8

Maximizing floral and fruity aromas is not the aim.

Question 9

Name 2 styles of white wine that that do not have a fruity, floral aroma and are therefore fermented at temperatures between 17-25°c.

Answer 9

1) White Rioja
2) Some Chablis styles

Question 10

Name 3 reasons why small oak barrels are used for making / fermenting white wine.

Answer 10

1) The wine maker does not want to preserve primary aromas and flavours.
2) More blending options possible because the wine in each barrel slightly different
3) The small barrel size Increases contact between wine / lees which contributes to texture

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Question 11

Describe white wine that has been fermented in small oak barrels. (2 points)

Answer 11

1) Deeper colour, fuller body (more lees contact, more oxygen exposure)
2) More integrated oak aromas due to yeast action during fermentation as well as maturation

Question 12

Why does fermentation and maturation in small oak barrels lead to better oak integration?

Answer 12

Both fermentation and maturation happen in oak so the lees interact with oak for a longer period of time.

There is less opportunity to lees and oak to interact if fermentation occurs in stainless steel and maturation occurs in oak.

Question 13

List 3 reasons why fermentation in small oak barrels adds to costs.

Answer 13

1) Buying barrels, and often lots of them (barriques only hold 225l)

2) Monitoring each small barrel

3) Time, insurance