Acids

Question 1

What is sensory evaluation

Answer 1

The systematic assessment of wine using the evidence provided by our senses

Question 2

In order for evaluation to take place what three things must the brain do

Answer 2

1) perceive stimulus
2) identify it
3) measure its intensity

Question 3

What are the three major thresholds of evaluation

Answer 3

Detection
Recognition
Differentiation

Question 4

What is an acid

Answer 4

Any chemical compound that, when dissolved in water, gives a solution with a hydrogen ion activity greater than water

Question 5

What are the six key acids in wine

Answer 5

Tartaric 
Malic
Succinic 
Lactic
Citric
Acetic

Question 6

Describe malic acid

Answer 6

Sharp, light bodied, green apple

Question 7

Describe tartaric acid

Answer 7

Steely, full bodied, neutral

Question 8

Describe lactic acid

Answer 8

Sour, milky, full-bodied

Question 9

Describe citric acid

Answer 9

Sharp, lemony, light bodied

Question 10

Describe acetic acid

Answer 10

Aromatic, vinegary, light bodied

Question 11

What is the most important acid in wine

Answer 11

Tartaric acid

Question 12

What are the benefits of tartaric acid

Answer 12

Aids chemical stability, stabilises colour and influences the taste of the final wine

Question 13

What is the concentration of tartaric acid dependent on

Answer 13

Grape variety and soil content

Question 14

What happens to the acid levels of tartaric acid during ripening

Answer 14

They hardly diminish

Question 15

What are the disadvantages of tartaric acid

Answer 15

They can form tartrates. This is a potential instability issue in the final wine

Question 16

What acid is found in most fruit and berries, notably in green apples

Answer 16

Malic acid

Question 17

Where would you find higher levels of malic acid and why?

Answer 17

In cooler climates due to degree of ripeness

Question 18

What are the benefits of succinic acid

Answer 18

It is stable and resistant to attack by wine bacteria and when combined with ethanol creates mild fruity esters

Question 19

Which acid is used as an artificial sweetener and acidity regulator

Answer 19

Succinic acid

Question 20

Which acid is a byproduct of the fermentation process

Answer 20

Succinic acid

Question 21

Which acid is found in very minute quantities in winegrapes

Answer 21

Citric acid

Question 22

What is the concentration of citric acid compared to tartaric acid

Answer 22

1/20

Question 23

Which acid is more harsh, tartaric or citric

Answer 23

Citric

Question 24

Which acid can react with bacteria to produce acetic acid

Answer 24

Citric acid

Question 25

What is the primary acid of yoghurt and milk

Answer 25

Lactic

Question 26

Where is the lactic acid produced

Answer 26

During winemaking by lactic acid bacteria

Question 27

What is milder than tartaric and malic acid

Answer 27

Lactic

Question 28

What is the most volatile acid found in wine

Answer 28

Acetic acid

Question 29

Acetic acid is formed in four ways: what are they

Answer 29

Formed by yeast during the alcoholic fermentation By bacteria fermenting citric acid during the malolactic fermentation By lactic bacteria converting residual sugar during stuck fermentations By acetobacter converting ethyl alcohol in finished wine, due to excessive exposure to oxygen

Question 30

Why is acidity important in wine

Answer 30

It influences colour, balance, taste and chemical stability

Question 31

What are the three key acids found in grapes

Answer 31

Tartaric Malic Citric

Question 32

Name two primary acids derived from fermentation process

Answer 32

Lactic and acetic

Question 33

How can you reduce the malic acid content

Answer 33

MLF | Converting malic acid into lactic acid