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Flashcards in Oenology Deck (41):
1

Dryness-Sweetness Scale:

French:
Sec, Demi-Sec, Doux

Germany
Trocken, Halbtrocken

Italy
Secco, Amabile/Abboceato, Dolce

Spain
Seco, no medium sweet, Dulce

Portugal
Seco, no medium sweet, Doce/Adamado

2

List a bunch of fortified wines

Port
Madeira
Sherry
Marsala
VDN
Setúbal
Carcavelos
Pico
Greece's OPE wines

3

3 general methods of fortification

1. Arrest fermentation by adding spirit while sugars remain, e.g. Port

2. Fortify after fermentation has finished, e.g. Sherry

3. Grape must fortified PRIOR to fermentation - produces a mistelle rather than a fortified wine, e.g. Ratafia (Champagne), Macvin du Jura, Pineau des Charentes, Floc de Gascogne

4

Continuous Method is aka ___. Where do you see it?

Russian Continuous Method. See it used for German Sekt.
- similar to Tank Method except base wine is pumped through series of continuous tanks while undergoing the 2nd ferment.
- L. de Tirage is constantly added and lees accumulate in the first several tanks, therefore offering higher autolyzed flavors thank regular Tank Method.

5

What causes a stuck fermentation?

1. If yeast cells are killed by natural inhibitors.
2. If yeast cells are killed by high fermentation temps.
3. If yeasts use up some needed nutrient.

6

Méthod Ancestrale is aka ___. Give an example.

Méthode Rurale, see it in Cordon de Bugey.
- at 6.5% abv wine is transferred to bite to continue fermenting. No Tirage, No Dosage.

7

Beneficio is the ____ of wine with spirit (it's aka Mutage).

Fortification
- It occurs when about 1/3 of sugar has been converted to alcohol.
- wine is fortified to 19-22% abv w/aguardiente, a 77% neutral grape spirit (usually 1:4 ratio)

8

What creates VA in a wine?

A small amount of remaining acetaldehyde is inevitably converted to acetic acid, which in turn reacts with alcohol to produce ethyl acetate (the VA smell). When volatile acidity is encountered as a fault, excessive acetic acid has been produced by the activity of acetobacter, the group of bacteria responsible for turning wine to vinegar in the presence of oxygen.

9

What can cause H2S (rotten egg smell)?

1. low levels of nitrogen in the must leads to the formation of hydrogen sulfide (H2S)
2. Adding too much SO2

10

Do mercaptans smell good or bad?

Bad

11

White wine fermentations are ___ and Red wine fermentation are usually ___.

Whites are cooler, reds are warmer (no more than 95F)

12

Are ambient yeasts the same thing as wild or native yeasts?

No. Ambient yeasts inhabit the winery and come to life in the presence of must. They are less predictable than cultured yeasts.

13

Name two ways to remove alcohol from wine.

1. Spinning cone
2. Reverse osmosis

14

What are the two parts of Reverse Osmosis?

Permeate - contains water and ethanol, is distilled to a proper level before being recombined with the...

Retentate—the wine’s aromatic compounds—at a lower percentage of alcohol

15

What are the 2 acids used to acidify wine?

Tartaric (preferred, added prior to fermentation) and malic

16

How is délestage different from remontage?

Délestage is when you drain the whole tank, the juice goes into another vessel, and then the juice is pumped over the cap in the fermentation vessel.

Remontage is a continuous pumping over of the must over the cap.

17

What is the French term for free-run?

Vin de goutte

18

What's the French term for pressed juice?

Vin de presse

19

What's the French word for racking?

Soutirage

20

What is collage?

Fining
- use isinglass, bentonite, casein, gelatin or egg white.

21

What is débourbage?

Settling

22

What's the German term for sterilized fresh grape juice?

Süssreserve

23

What are the 3 basic methods of making rosé?

Blending - when you blend red and white wines (champagne).

Limited skin maceration

Saignée - bleeding off

24

What are some flavor compounds that oak imparts on a wine?

Lactones and phenolic aldehydes, such as vanillin.

25

What is microbullage?

Micro-oxygenation

26

What are the species of oak trees used in France? In America?

France: q. robur and q. petraea
America: q. alba

27

What is the difference in the way French barrels and American barrels are dried?

French oak is usually air-dried, a gentle process that leaches out some of oak’s more aggressive tannins and flavors, whereas American oak is quickly kiln-dried, and lactones are concentrated.

28

What are the 3 stages of heating/shaping staves?

Warming (chauffage), Shaping (cintrage), and Toasting (bousinage).

29

Light toast promotes the most extraction of wood tannin. True or False?

True

30

What is the approximate ideal average summer temperature for white grapes?

66F

31

A controversial form of micro-oxygenation, ___, occurs during élévage.

cliquage

32

In MLF there is a drop in ___ and a shift in __, the degree of how much depending on the amount of ___ acid.

drop in acidity, shift in pH, malic acid.

33

An average pH level in wine and grape juice is ___.

3 to 3.8, which is quite acidic.

34

What's the difference between LAB heterofermentative or homofermentative?

Hetero - produces lactic acid, acetic acid, and ethanol,
Homo - makes only lactic acid

35

Oenococcus oeni is the one species of LAB that winemakers want to carry our MLF because...

it produces the best results (they're resistant to hostile conditions).

36

LAB produce acetic acid from metabolizing sugars, increasing ___ ___.

volatile acidity

37

List some factors that favor diacetyl production.

1. the presence of oxygen
2. high concentrations of citric acid and sugar
3. temperatures below 18 °C
4. the removal of yeast cells before MLF

38

What's the smell of toast, popcorn, and hazelnut?

Thiazole

39

When a wine smells like rotting cabbages or smelly socks (mercaptans), what caused that?

The production of volatile sulfur compounds (VSCs), These are produced by the metabolism of the sulfur-containing amino acids cysteine and methionine

40

Sensitivities including headaches, breathing difficulties, hypertension or hypotension, allergic reactions, and palpitations are caused by what?

A byproduct of MLF called biogenic amines. All fermented products contain them, but malolactic bacteria are capable of producing reasonably high levels.

They are formed by the decarboxylation of amino acids, and the major ones found in wine are histamine, tyramine, putrescine, and phenylethylamine.

Not all strains of LAB are able to decarboxylate amino acids. The higher the wine’s pH, the more complex the range of bacterial species that will grow in it. As a result, there will usually be higher levels of biogenic amines.

Although sulfites are often blamed for allergic reactions to wine, it’s much more likely to be the biogenic amines that are responsible, although this hasn’t been proven conclusively.

Currently, there are no regulations for biogenic amine levels in wine, but this could change.

41

Co-inoculation with compatible strains of bacteria and yeasts is commonplace now, and is used mostly for what style of wine?

Inexpensive reds. The result is fruitier wines (especially reds), in part because any diacetyl produced by the bacteria is used by the yeasts, and there's the added bonus of no risk period between the end of alcoholic fermentation and the beginning of MLF.