Wine Composition

Question 1

A bottle of wine is roughly this percentage water

Answer 1

86%

Question 2

Aroma and color and flavor is what percentage of a bottle of wine by weight

Answer 2

3%

Question 3

Above this degrees Fahrenheit water stress can delay ripening

Answer 3

95°F

Question 4

How does frost damage a vine?

Answer 4

Destroys green plant tissue. limits, ability to ripen fruit

Question 5

Skins of grapes contribute what percentage of a grape

Answer 5

5 to 15%

Question 6

In what decade were rotary fermenters introduced, and malolactic starter cultures became commercially available in wine

Answer 6

1980s

Question 7

When were the first active dry yeast produced commercially?

Answer 7

1965

Question 8

And what decade was the de Stemmer crusher reoriented so crushing followed De stemming

Answer 8

1970s

Question 9

In what decade were the first instances of pure bacterial culture used to induce maloactic fermentation?

Answer 9

Late 1950s

Question 10

What year was the Vaslin horizontal plate press popularized

Answer 10

1945

Same year Andre Tschelitscheff demonstrated the benefits of cold fermentation temperature

Question 11

Who postulated that bacteria is responsible for acid reduction in wine

Answer 11

Hermann Muller (1891)

Question 12

Who posited that Malic acid is converted to lactic acid by CO2 and bacteria?

Answer 12

Hermann Muller and Osterwalder

Question 13

Who discovered the yeast is the agent of fermentation?

Answer 13

1850s Louis Pasteur (1857)

Question 14

Emile Peynaud
Brad Webb

isolated this bacterial culture?

Answer 14

The first Malolactic Culture

Question 15

Why would a wine that has just been sulfured look bleached

Answer 15

Sulfur binds to anthocyanins temporarily to create colorless complexes, making juice looke bleached

Question 16

What creates tannin effect in a drinker?

Answer 16

Tannins bind with proteins in the drinker’s mouth

Question 17

After a year of fermentation and aging, the color of red wine is driven by this

Answer 17

Concentration of polymeric pigments

Question 18

Polymeric pigments are associated with this sensation mid palate

Answer 18

Fruit sweetness

Question 19

Two examples of phenolics

Answer 19

Tannins and Anthocyanins

Question 20

Three acids formed during fermentation

Answer 20

Lactic
Succenic
Acetic

Question 21

Two parameters for measuring acidity

Answer 21

PH
Titratable Acidity

Question 22

What is the primary organic acid occurring naturally in grapes?

Answer 22

Tartaric

Other natural grape acids are malic and citric

Question 23

When is the wine dry?

Answer 23

Less than 2 g/L liter or
Or zero to -3° brix

Question 24

Why do hydrometers measure negative brix as fermentation begins

Answer 24

Alcohol is less dense than water, placing sugar

Question 25

General range of brix for dry or sparkling wine

Answer 25

18 to 27 Or 180 to 270 g/L of residual sugar

Question 26

Scales for estimating sugar content of juice in fermenting grape must

Answer 26

Brix Baumé Oeschle Klosterneuberg (KMW or Babo) CNM

Question 27

What are the two main grape sugars?

Answer 27

Glucose and fructose

Question 28

Most unfermentable sugars are this where glucose and fructose are hexoses (six carbon)

Answer 28

Pentoses