Lecture 13: Alcohol 1

Question 1

_______ is a biological process in which sugars from plants (e.g., glucose, fructose, and sucrose) are converted into cellular energy, ethanol and carbon dioxide as metabolic waste products.

Answer 1

Alcoholic fermentation (ethanol fermentation)

Question 2

True or False: Because yeasts perform this conversion in the absence of oxygen, alcoholic fermentation is an anaerobic process.

Answer 2

True

Question 3

Alcohol fermentation was discovered by?

Answer 3

1810 by Gay-Lussac

Question 4

What 3 things did alcohol fermentation lead too?

Answer 4

Production of alcoholic beverages

Rising of bread dough

Ethanol fuel

Question 5

How could birds get drunk?

Answer 5

Particularly fruits that are damaged (i.e. the skin is broken) are colonised by S. cerevisiae, which is transmitted by bees, wasps, and Drosophila.

Question 6

True or False: Most important civilizations empirically discovered fermentation and produced an alcoholic beverage from grapes (wine) or from other fruits (cider) was probably accidental.

Answer 6

True

Question 7

______ is a liana (woody vine) with tendrils and palmate leaves

Answer 7

The grape wine

Vitis vinifera

Question 8

What is the fruit of wine?

Answer 8

Berry

Question 9

True or False: Wine was domesticated independently at least 2 times.

Answer 9

True

Transcaucasia and W Mediterranean area.

Question 10

_____ earliest wine making in Europe.

Answer 10

Greeks (ca. 6500 ya.)

Question 11

_______ developed cultivation on trellises, making white and red wine (5000 y old sealed wine jars found in tombs).

Answer 11

Egyptians

Question 12

_______ classified grape varieties and made many innovations: developed the press, barrels, adding spices and herbs to the wine

Answer 12

Romans

Question 13

_______ = the science of growing grapes (Vitis vinifera)

_______ = the science of making wine

Answer 13

Viticulture

Oenology

Question 14

_______ was the Greek god of the grape harvest, winemaking and wine, of ritual madness and ecstasy in Greek mythology.

________ is the Roman equivalent , the god of wine and intoxication

Answer 14

Dionysus

Bacchus

Question 15

True or False: Dionysus thus came to be considered a patron of the arts

Answer 15

True

Question 16

_______ introduced wine making and wine to France, Germany, England

Answer 16

Romans

Question 17

One was one of the first grapes introduced to California in 1769 by Father Junipero Serra?

Answer 17

Mission grape

Question 18

The time of harvest is determined primarily by the _______ and _______.

Answer 18

content in sugar (15—20% glucose and fructose)

acid

Question 19

Sugars are stored in the ______ along with water, organic acids and other compounds.

Pigments are stored in the _______.

Tannins are present in the _____.

Answer 19

pulp (mesocarp)

epicarp (“skin”)

seeds

Question 20

_______ is the process required to gently squeeze the berries and break the skins to liberate the grape juice.

Answer 20

Crushing

Question 21

The resulting mix of skins, juice and seeds is called ______.

Answer 21

must

Question 22

_______ squeezes the skins the extract the remaining liquid and separates it from the skins and seeds.

Answer 22

Pressing

Question 23

Red wines are produced by leaving skins in contact with the juice (_______)throughout the fermentation

Answer 23

(maceration)

Question 24

How are white wines made vs red wines?

Answer 24

With white wines, grapes are crushed, pressed and then fermented.

With red wines grapes are crushed, macerated-fermented, and then pressed to remove the skins.

Question 25

True or False: Fermentation ends when there are no more sugars in the wine.

Answer 25

True

Question 26

______ is added to juice to inhibit the growth of unwanted yeasts and bacteria brought in with the grapes and removing oxygen from the fermentation vats insuring that Acetobacter spp. will not turn the resulted ethanol into acetic acid

Answer 26

SO2

Question 27

If higher concentrations of alcohol are desired, the wine must be _______.

Answer 27

fortified or distilled.

Question 28

_______ may involve filtration, centrifugation, refrigeration. _______ involves pasteurization, and/or treatment with sorbic acid.

Answer 28

Clarification and stabilization Stabilisation

Question 29

Malolactic fermentation occurs when lactic acid bacteria (Lactobacillus spp.) metabolize ______ and produce ______ and ______

Answer 29

malic acid lactic acid and carbon dioxide Happens in all red wines and some white

Question 30

True or False: bottles that are often flushed with N to minimize exposure to oxygen

Answer 30

True

Question 31

_______Is an aerobic fermentation in which alcohol is converted into acetic acid (vinegar) by bacteria of the genus Acetobacter, esp. A. aceti

Answer 31

Acetic fermentation

Question 32

True or False: Research shows that people’s enjoyment of wine is influenced by how much it costs

Answer 32

True

Question 33

True or False: A third alcoholic fermentation is necessary to produce CO2 in the wine. The classical method (developed in the Chapagne region is to do that directly in the bottle.

Answer 33

False, second

Question 34

Sediments from the 2nd fermentation accumulate in the cap and they are eliminated through a process called _______

Answer 34

disgorgement

Question 35

True or False: You want to buy a sparkling wine in which CO2 results from a second fermentation not from CO2 injected, soda-like wine

Answer 35

True The bubbles are finer and the fizz lasts longer.

Question 36

_______ wines are wines which are added alcohol (usually brandy) to make them stronger (15-21% ethanol) and the additional ethanol acts as a preservative.

Answer 36

Fortified

Question 37

True or False: In Canada, per capita consumption of wine has been rising slowly and steadily for years and Canadians currently go through about 6 litres of wine per capita

Answer 37

False, 13 L per capita