Common Elements in Winemaking and Maturation UNFINISHED

Question 1

What are the major four constituent parts of a grape?

Answer 1

Seeds and stems (tannin)
Skins (tannin and flavour)
Bloom (waxy surface, contains yeast)
Pulp (sugar, acid, water)

Question 2

What is the benefit of picking grapes at night in terms of oxygen exposure?

Answer 2

Chemical reactions occur much slower at low temperatures

Question 3

What might be used to fill airtight vessels used for protective winemaking?

Answer 3

Co2

Question 4

Some people might argue that wines made protectively lack what?

Answer 4

Complexity and interest

Question 5

What will a concrete tank be lined with in order to make it inert?

Answer 5

Epoxy resin

Question 6

How many litres in a barrique?

Answer 6

225L

Question 7

What two things does sulphur dioxide act as in the winery?

Answer 7

antioxidant and antiseptic

Question 8

What are some issues associated with sulphur dioxide use in wine?

Answer 8

High levels are toxic
Small amounts can cause allergic reactions
Too much and wine can seem harsh and lacking in fruit

Question 9

How many uses can you get out of a barrel before it imparts little flavour or tannin?

Answer 9

4

Question 10

What are the two types of press systems?

Answer 10

Basket press

Pneumatic press

Question 11

Where are basket presses commonly used?

Answer 11

Champagne

Question 12

What are separated volumes of pressed juice called?

Answer 12

Fractions

Question 13

What is used in wine ‘enrichment’ of must when there is insufficient sugar in the grape?

Answer 13

Rectified Concentrated Grape Must (RCGM)

Question 14

What is it called when sugars that are not from rectified concentrated grape must are added to wine?

Answer 14

Chaptalisation

Question 15

Aside from additions, what can be done to must to increase sugar concentration?

Answer 15

Removing water from must (this also concentrates tannin, acid etc.)

Question 16

What acid and in what form is sometimes added to grape juice when levels are insufficient?

Answer 16

Tartaric acid in powder form

Question 17

Deacidification can be achieved by the addition of what?

Answer 17

An alkali

Question 18

What is the scientific equation for alcoholic fermentation?

Answer 18

Sugar + yeast = alcohol, flavour compounds, heat and Co2

Question 19

What is the yeast responsible for the majority of wine fermentations?

Answer 19

Saccharomyces cerevisiae

Question 20

Alcoholic fermentation will not start if the temperature is below what?

Answer 20

5*C

Question 21

At what upper temperature will alcoholic fermentation cease?

Answer 21

35*C

Question 22

Name 3 reasons why fermentation may stop before all sugar is consumed?

Answer 22

Temperatures exceed 35*C
Yeasts run out of nutrients (other than sugar)
Too much sugar and alcohol

Question 23

What are three ways of killing/removing yeast?

Answer 23

So2
Adding grape spirit (fortified wines)
Chilling wine below 5*C to halt yeast activity and then filtering

Question 24

What are two ways a winemaker can manipulate temperature during fermentation?

Answer 24

Heating/refrigeration

By pumping over

Question 25

Briefly explain MLF. Name the bacteria necessary.

Answer 25

Lactic acid bacteria converts tart malic grape acid into softer lactic acid.

Question 26

How is MLF encouraged?

How is it inhibited? (3)

Answer 26

By increasing the temperature of the wine and not adding So2

Storage at cool temperatures, the use of So2 or by filtering bacteria

Question 27

How is MLF discouraged?

Answer 27

So2
storage at cool temperatures
filtering out bacteria

Question 28

Dead yeast cells and grape fragments that settle to the bottom of the fermentation storage vessel within are few hours are called?

Answer 28

Gross lees

Question 29

What characteristics does a wine need sufficient levels of to survive medium-long term ageing?

Answer 29

Tannin, acidity and/or alcohol and will need flavours that will develop in an interesting way