Vinification

Question 1

Primary flavors in wine come from: the grapes, fermentation, or age?

Answer 1

Grapes themselves

Question 2

What sugar does yeast prefer to consume?

Answer 2

Glucose

Question 3

What is the conversion ratio used to estimate potential alcohol in the EU?

Answer 3

16.83 grams per litre of sugar in the must yields 1% abv

Question 4

Yeasts convert roughly what % of sugar into alcohol?

Answer 4

90-95%

Question 5

What is the main acid in grapes, are there others?

Answer 5

Tartaric
Yes, Malic & Citric

Question 6

How do pH and TA differ in the perception of a wine?

Answer 6

pH affects texture
TA affects how “sour” a wine will be

Question 7

What are the three categories of Phenolic compounds?

Answer 7

Flavonoids (polyphenols like Anthocyanins and Catechins)
Non-Flavonoids
Tannins

Question 8

Which method of white wine pressing yields a higher degree of skin contact: destemming before pressing or whole-cluster pressing?

Answer 8

Destemming before pressing

Question 9

In what style of winemaking is whole cluster pressing generally favorable?

Answer 9

Sparkling wine production

Question 10

When does extraction begin in red winemaking?

Answer 10

As soon as berries are crushed

Question 11

Are whole cluster fermentations warmer or cooler than destemmed fermentations?

Answer 11

Cooler - stems provide channels for airflow

Question 12

What style of red winemaking is semi-carbonic?

Answer 12

Whole cluster

Question 13

At what % of alcohol does intracellular fermentation generally stop?

Answer 13

2%

Question 14

What are Pectolytic enzymes?

Answer 14

Enzymes that break down pectin in grape skins, used to increase extraction in a short period of time

Question 15

What are the three methods of rose production ?

Answer 15

Direct press
Saignee
Blending

Question 16

What is cold soaking?

Answer 16

Process where red must is held at a cool temperature to inhibit fermentation
Fruit enzymes break down skins to increase color

Question 17

Are thermoinification and flash detente used in quality winemaking?

Answer 17

No

Question 18

At what point does extraction end?

Answer 18

Pressing

Question 19

What is the press cut?

Answer 19

When a winemaker decides when to switch from a light press to heavy press juice

Question 20

What method of pressing is preferred for quality winemaking: Batch pressing or Continuous pressing?

Answer 20

Batch pressing

Question 21

What is debourbage?

Answer 21

Settling of must overnight at a cold temperature then racking off sediment - done post pressing

Question 22

When is Bentonite clay added to a wine to clarify it? How does it work?

Answer 22

After pressing before racking
Natural electrostatic processes (positively charged connects to negatively charged ions in the juice)

Question 23

How might alcohol be adjusted in the winemaking process?

Answer 23

If potential alcohol is too high adding water to the must in tank BEFORE fermentation

Question 24

During the process of Malolactic fermentation, what does Citric acid turn into?

Answer 24

Diacetyl

Question 25

Does MLF increase or decrease a wines total acidity?

Answer 25

Decrease

Question 26

What is the name of the main wine yeast?

Answer 26

Saccharomyces cervisiae

Question 27

What is the name of the LAB that causes MLF?

Answer 27

Oenococcus oeni

Question 28

Non-saccharomyces yeasts generally die off after what point in the winemaking process?

Answer 28

Just after fermentation begins

Question 29

Botrytis is likely to carry what genus of Yeast? What does this yeast produce a lot of?

Answer 29

Pichia yeasts It's a spoilage yeast that produces a high amount of VA

Question 30

What yeast strain produces a higher proportion of ethyl acetate?

Answer 30

Kloeckera apiculata - a cold tolerant yeast

Question 31

Is Brettanomyces bruxellensis an alcohol tolerant yeast variety or not?

Answer 31

It is very alcohol tolerant

Question 32

LAB converts glucose into what?

Answer 32

Lactic acid

Question 33

What are biogenic amines and what causes them?

Answer 33

Off-putting aromas of putrescine and cadaverine Caused by undesired LAB species

Question 34

What are pyridines and what causes them?

Answer 34

Aromas of mousiness, flavors of acrolein (bitter), and causes ropiness caused by undesired LAB species

Question 35

What is ropiness in wine?

Answer 35

It's a viscous slime that forms from polysaccharides linking together

Question 36

What is the species of Acetic acid bacteria that can live in wine?

Answer 36

Acetobacter

Question 37

What causes populations of acetobacter to rise?

Answer 37

Exposure to oxygen post fermentation Can be managed by topping up barrels and also with SO2 during aging

Question 38

Roughly how much C02 is produced in relation to volume of the must ?

Answer 38

CO2 is 60x greater than the volume of the must

Question 39

Is fermentation a reductive or oxidative environment?

Answer 39

Reductive - CO2 displaces oxygen

Question 40

How many yeast cells per milliliter are generally required for fermentation to begin?

Answer 40

Roughly 10 million cells

Question 41

What are the three stages for yeast during fermentation?

Answer 41

Lag phase - yeast adapting to environment Exponential phase - reproduction Stationary phase - the act of fermentation

Question 42

If nitrogen is too low during a fermentation what aroma can be produced? How does this actually affect the act of fermentation?

Answer 42

Hydrogen Sulfide (rotten eggs) Can lead to a stuck fermentation

Question 43

What are mercaptans? What are they derived from?

Answer 43

Bad smelling thiols (skunk, onion, rubber) Created when hydrogen sulfide is produced and reacts w/ the wine to create other compounds

Question 44

What is the temperature range that yeasts generally are able to operate within?

Answer 44

45-95 degrees Fahrenheit

Question 45

What temperature range are yeasts most active in?

Answer 45

70-80 degrees Fahrenheit

Question 46

What is the process of Remontage?

Answer 46

Pump overs

Question 47

What is the process of Pigeage?

Answer 47

Punch downs

Question 48

During Remontage what is the use of the "sprinkler" vs. "fire hose" technique?

Answer 48

Sprinkler will be less extractive Fire hose is much more extraction

Question 49

What is Delestage?

Answer 49

Rack and return Removes the must to another tank w/ skins left behind then pumping the must back over the skins to mix thoroughly

Question 50

Where is Submerged Cap fermentation historically popular?

Answer 50

Piemonte

Question 51

Besides Lactic acid, what other compounds are created during MLF?

Answer 51

Acetic acid Acetaldehyde Diacetyl

Question 52

Where was the technique of microoxygenation popularized?

Answer 52

Madrian in the 1990's

Question 53

What does microoxygenation try and mimic?

Answer 53

Aging in a porous vessel like oak

Question 54

What wine fault is risked when microoxygenation is used?

Answer 54

Prem-ox

Question 55

What is cliquage?

Answer 55

A technique that mimics the oxidative effects of racking with one large hit of O2

Question 56

Are the following forests know for having tight grain, medium grain, or coarse grained oak: Troncais Allier Jupilles Nevers Bertranges Vosges Limousin Zemplen Hills (Hungary)

Answer 56

Troncais - Tight Allier -Tight Jupilles - Tight Nevers - Medium Bertranges - medium Vosges - loose Limousin - Coarse Zemplen Hills - tight

Question 57

If wines use 100% new oak how does the price increase per bottle (French and American)

Answer 57

French: $3.30-$7.50 / bottle American: $1.65 + /bottle

Question 58

What is the humidity range where alcohol and water evaporate at the same rate? If lower/higher, what happens to the wine?

Answer 58

70% If lower - alcohol increases as water evaporates w/o the alcohol If higher - alcohol decreases

Question 59

What is the process of Ouillage? How often is it practiced?

Answer 59

Topping up of barrels Every 2-6 weeks

Question 60

May USDA certified organic wine contain added sulfites?

Answer 60

No

Question 61

May USDA certified wine made from organic grapes contain added sulfites?

Answer 61

Yes up to 100ppm of SO2

Question 62

When might SO2 be added to a wine?

Answer 62

Before fermentation to inhibit bad bacteria or undesirable yeast During fermentation (stopping it) After MLF to prevent oxidation At bottling to inhibit oxidation that naturally happens during bottling

Question 63

What is the French term for racking?

Answer 63

Soutirage

Question 64

What is protective racking?

Answer 64

An anaerobic way to rack a wine pushing wine from a barrel using inert gasses

Question 65

What is the tool that is used to rack a wine?

Answer 65

A racking wand or racking arm

Question 66

How can mercaptans be removed from a final wine?

Answer 66

Using copper sulfate - reacts w/ insoluble compounds that fall out of solution

Question 67

What are the legal limits of Copper sulfate use in the US and EU?

Answer 67

.5mg/L in the US 1mg/L in the EU

Question 68

What is copper casse?

Answer 68

Excess copper in a wine that increases rate of oxidation and can cause haziness or a reddish/brown particulate in white wine