Midterm Flashcards
Basic definition of wine
fermented juice of grapes
major components of wine
- water
- alcohol
- sugar
- phenolic compounds
percentage of water in wine
80-90%
percentage of alcohol in wine
10-15%
ethyl alcohol (ethanol)
the primary results of alcoholic fermentation and the main alcohol component of wine
wines with high levels of alcohol vs low levels in terms of body
heavier and lighter respectively
percentage of acid in wine
.5-.75%
6 principal acids found in wine
- tartaric acid
- malic acid
- citric acid
- lactic acid
- acetic acid
- succinic acid
tartaric acid
the most prevelant of the acids found in both grapes and wine. It is also the strongest in terms of pH. Forms wine diamonds at low temperatures
malic acid
sharp tasting acid frequently associated w/ green apples.
citric acid
is not usually considered to be a natural component of grapes it is sometimes added to increase the total acidity in a wine
lactic acid
it is not found in grapes it is created in wine by adding lactic acid bacteria which convert malic acid to lactic acid through malolactic fermentation
acetic acid
the acid found in most types of vinegar. A low level is typically created during fermentation but a high concentration can be unpleasant and make wine undrinkable
two ways to describe the acidity level of a wine
total acidity (TA) and pH
Total Acidity (TA)
the volume of all the acids in a wine
pH
represents the combined chemical strength of acids present
percentage of sugar in grapes
15-28% at harvest
The two types of sugars that appear in grapes
- glucose
- fructose
phenolic compounds (phenolics, polypehnolics, polyphenols)
a large category of various molecules that are present in many wines
examples of phenolic compounds
- anthocyanins
- flavones & flavonols
- tannins
- vanillin
- resveratrol
anthocyanins
compounds that give red wine its color
flavones & flavonols
yellow pigments found in white wines that increase in grapes w/ increased exposure to sunlight
tannins
astringent or bitter compounds found in the skins, seeds, and stems of grapes. they are a natural preservative and help to protect red wines from oxidation during the aging process
vanillin
an aromatic phenolic compound in oak that imparts a vanilla scent to barrel-aged wines
resveratrol
a compound in wine believed to have several beneficial health effects in humans
aldehydes
oxidized alcohols that are from when wine is exposed to air.
esters (ethyl acetate)
represent the largest group of odiferous compounds. at low concentrations - fruity/flowery aroma; high concentrations - nail polish remover, varnish, or glue
3 types of wine faults
- TCA
- Sulfur
- Bacteria
Trichloroanisole (TCA)
musty, moldy odor similar to that of a dank basement. referred to as being corked or as having cork taint. The culprit is a mold which can grow on and in the bark of the cork oak tree
3 types of sulfur compounds
- sulfur dioxiode (SO2)
- Hydrogen sulfide (H2S)
- Mercaptan
sulfur dioxiode (SO2)
causes an acrid smell similar to that of burnt matches and can cause an unpleasant burning sensation in the throat or nose
Hydrogen sulfide (H2S)
causes an odor of rotten eggs. This happens most often when a barrel or tank of wine rests for a long time with a large amount of yeast sediment at the bottom
mercaptan
forms from a combination of sulfur and ethanol and causes a smell like garlic or onions
two types of bacteria that can survive in a highly acidic environment
- lactic bacteria
- acetobacter
lactic bacteria
are responsible for malolactic fermentation intentional or otherwise
Acetobacter
can convert alcohol into acetic acid
acetic acid odor
vinegar
butyric acid odor
rancid butter or spoiled cheese
lactic acid odor
sauerkraut or goat cheese
geranium odor
crushed geranium leaves caused by incomplete malolactic fermentation
Brettanomyces (Brett)
a member of the yeast family and causes a sweaty or horsy odor. Also described as Band-Aid like or medicinal
Green odor
the smell of leaves usually resulting from the use of immature (under-ripe_ grapes
oxidized
odor of nutty/caramelized character
maderized
a cooked or baked odor resulting from excessive heating or oxidization
moldy
odor resulting from the use of moldy grapes or barrels
rubbery
odor associated w. very low acid wines or excess sulfur
stagnant
stale water odor
stemmy
better green odor of grape stems
wet cardboard
a paper chemical odor associated w/ cork taint
yeasty or leesy
may develop if dead yeast remains in contact with the wine too long
reduction or reductive
refers to a smell of rotten eggs, garlic, struck matches, cabbage, or burnt rubber
sensation
refers to an organism’s neurological response to a stimulus in the environment
perception
involves the brain’s interpretation of the information gathered by the senses
sensory stimulus
any chemical, physical, or thermal activator that can produce a response in a sense receptor
detection threshold
indicates the smallest amount of stimulus needed to trigger an unidentifiable sesation
recognition threshold
refers to the smallest amount of stimulus required to trigger an identifiable sensation
olfactory epithelium
the sensory organ for the sense of smell is a small patch of special tissue located on the roof and wall of the inside of the nose
the stalks contain
tannins
the pulp contains
- sugars
- acids
- water
the skin contains
tannins
color
flavor
the pips contains
bitter oils
5 primary tastes
- sweet
- salty
- acid/sour
- bitter
- umami
5 classifications of wine
- table wine - (7-15%) alcohol
- Dessert wine - residual sugar
- fortified wine - alc. added, 15-20%
- sparkling wine - CO2 - natural or added
- Aromatized - flavored w/ herbs & spices
Grape Genus
Vitis
Grape Species
- Vinifera
- Labrusca
- Rupestis
Grape Variety
Chardonnay
Riesling
Cab
Sauv Blanc
Clone
Chardonnay - AXR1, Dijon 95 FPMS 4
Chardonnay Grapes
grows in a range of climates made in wide range of styles characteristics vary with climate acidity high in cooler climates low in hotter climates
Chardonnay Tastes
cool climate: citrus/green fruit, lemon, apple, pear
moderate climate: stone/white fruit, melon, peach, hot climate: tropical fruit, banana, pineapple, mango
malolactic fermentation: dairy, butter, cream
lees contact: savoury, bread, yeast, creamy texture
oak ageing: wood, toast, nuts, vanilla
Top Producing Chardonnay Countries
France (Burgundy & Champagne), USA, Australia
sauvignon blanc grape characteristics
Acidity: High
Alcohol: Medium
Sauvignon blanc tastes
- citrus
- green (apple)
- herbaceous
Top producing sauvignon blanc countries
- France (Bordeaux & Loire Valley)
- New Zealand
- USA,
- Chile
- South Africa
Riesling Tastes
- citrus
- floral
- stone fruit
- petrol
Riesling Characteristics
Acidity: High to Very High
Alcohol: Very low to High
Top Producing Riesling Countries
Germany
Alsace (France)
Australia
USA
Pinot Grigio Grape Characteristics
grown throughout Italy
dry
light to medium body
medium acid
Pinot Grigio Flavours
delicate green & citrus fruit
green apple
lemon
Pinot Gris Grape Characteristics
classic region Alsace
dry, medium or sweet
full bodied
Pinot Gris Flavours
tropical fruit/spice banana melon ginger honey
Cabernet Sauvignon Grape Characteristics
needs a moderate or hot climate deeply coloured with high levels of tannins and acidity pronounced aromas produces wines for ageing oak often used to mature wines
Cab Sauvignon Flavour
moderate climate: black fruit blackcurrant bell pepper herbaceous hot climate: black fruit blackcurrant black cherry eucalyptus mint
Merlot Grape Characteristics
needs a moderate to hot climate
lighter in colour, acidity and tannins than Cabernet Sauvignon
higher in body and alcohol
oak often used to mature wines
Merlot Flavours
moderate climate: red fruit red berry strawberry red plum hot climate: black fruit blackberry black plums black cherry fruitcake/chocolate
Pinot Noir Grape Characteristics
prefers a cool or moderate climate
lightly coloured
low levels of tannins
most wines best consumed when young
Pinot Noir Flavours
Fruit character: red fruit
strawberry
raspberry
red cherry
best examples can age and develop gamey aromas
Pinot Noir Top Producing Countries
France (Burgundy)
USA (Oregon & CA)
Germany
Syrah/Shiraz Grape Characteristics
needs a moderate or hot climate
deeply coloured and usually full bodied
medium or high levels of tannins and medium acidity
oak often used to mature wines
Syrah/Shiraz Flavours
moderate climate: black fruit/pepper blackberry black pepper hot climate: black fruit/sweet spice blackberry liquorice dark chocolate maturity vegetal leather
Grenache/Garnacha Grape Characteristics
needs a hot climate
lighter in colour
full-bodied with high levels of alcohol and low acidity
used for the production of rosé wines
Grenache/Garnacha Flavors
hot climate: red fruit strawberry raspberry white pepper clove liquorice
4 senses used to evaluate and appreciate wine
-sight
-smell
-taste
touch
phylloxera
an aphid-like insect which ravaged European vineyards in the 19th century and continues to wreak havoc worldwide
clones
Grapes that are slightly different from their parent. This can occur when asexually reproduced grapevines are planted in new surroundings and slight genetic variations occur as the plant modifies itself to adapt to its new conditions.
The Key Factors that Affect Style Quality and Price
grape variety environment grape growing winemaking maturation
What a vine needs to grow
sunlight
water
warmth
nutrients
typical wine characteristics of hot climates
-more alc
more tannin
fuller body
less acidity
typical wine characteristics of cool climates
less alc
less tannin
lighter body
more acidity
the worlds wine producing area’s
lie between 30 degrees and 50 degrees north and south latitude
Viticulture
Managing the vines health
free from disease and pests
Guiding its growth thru the use of Pruning, Training & Trellising
Manage the canopy and the yield
diseases that can hurt vines
Viruses (plants)
Bacteria (insects)
Funghi (airborne - humidity)
pests that can hurt vines
phylloxera
deer
Yield
The resulting quantity from a specific measure of grapes or land
Examples: Tons of grapes per acre Hectoliters (26gal) per hectare (2.47 acres) Liters per marc Vines per acre
viticulture
branch of agriculture that specifically deals with the intentional cultivation of grapevines
winegrowing
when grapes are grown specifically to make wine, as opposed to juice or table grapes
Cloning for grapevine propagation
the grower can choose a healthy grapevine that is known for having desirable characteristics, cut off a short length of a young cane, place it in water where it will start to grow roots and then plant it in the vineyard
Field grafting
as long as the rootstock ( the trunk and major root system) is healthy, the grower can remove its existing brances, make a small incision into the trunk, and insert an unrooted cutting from a desirable vine from another vineyard. The cutting & rootstock will heal at the wound site and the cutting will begin to grow as if it had been planted in the ground, except that it will have have access to an extensive root network
Third leaf
the first crop of grapes to be used to make wine is normally harvested in their third year
When does the viticulture process start
with the emergence of new greenery in the spring, once temperatures start to get above 50F
bud break
tiny shoots called buds emerge from nodes in the vine’s branches
flowering
the next critical phase that takes place 40-80 days after bud break. clusters of tiny flowers appear at intervals along the shoots, and each flower that is fertilized will become the foundation for one or more grapes
berry set/ fruit set
the transition from flower to berry
coulure
(shatter in english) can cause poor fruit set with many flowers failing to become fully developed berries
millerandage
(abnormal fruit set) sometimes caused by bad weather during flowering, results in grape bunches that have a high proportion of small seedless berries mixed in with the normal larger seed-bearing grapes
veraison
signals a sudden acceleration toward maturation. it is most noticable in red grapes, which begin to take on color. white grapes also chance in appearance, remaining green but becomin translucent or golden
The time period from bud break to harvest
around 140-160 days
respiration
occurs as the plant breaks down sugar and related carbohydrates in order to release their energy for use by the plant for activities such as root and leaf growth
transpiration
the process by which water evaporates through openings on the underside of the leaves known as stomata
translocation
the process by which materials are moved from one area of the plant to another
weather
the actual meterological conditions experienced. It is the most chanageable and uncontrollable of the variables that go into making wine and is often the biggest factor that causes one vintage to be different from the next
climate
the historal average weather of a place, what is expected in the long term
microclimate
refers to the typical weather of a small area. Experts use the term to mean the environment within and directly surrounding a single vine’s canopy or at most a section of a row
mesoclimate
conditions of an entire vineyard
macroclimate
refers to the conditions of the overall region
oidium
a powdery mildew that is a damaging fungal disease
peronospora
a downy mildew that is a damaging fungal disease
Botrytis Cinera
when it is present at the wrong time or on grapes that are detrimentally affected by it, it is known as gray mold and wreaks havoc with the ripening grapes. It is used to make fine sweet wines
pre-fermentation
referred to as the “crush” ecompassing not only the actual crushing (if any) of grapes but also everything that gets the juice ready for the initiation of fermentation
sorting
the first stop in grape reception where leaves, underripe bunches, damaged fruit, and other debris can be removed before processing begins. This is usually done by hand but it can be partially mechanized
crusher-destemmer machine
this piece of equipment is designed to break open the berries and release the juice. at the same time the grapes are separated from the stem structure of the bunch which is then discarded. The result is a lot of liquid containing skins and seeds but no stems. Sometimes this step is eliminated for white wines
crushing
must be done gently as too much force can cause the release of tannins from the skins and seeds, whose astringency and bitterness are undesirable
pressing stage
fresh grapes, whether crushed first or not, are poured into the press in order to separate the solids from the juice; minimal skin contact is usually the standard. The skins could provide harsher tannins and flavors.
free run
the juice that immediately drains out of the press caused by the movement of grapes since harvest. Is very high quality
pomace
the cake of dry compressed skins and pips that remains after the final pressing
must
grape juice that is destined for fermentation
acidification
the process of adding acid directly to the must to increase acidity. it is generally done with tartaric acid
chaptilization
sugar is cautiously added to the must to increase the sugar levels
débourage
the process of letting the juice settle for a day or two before allowing fermentation to begun
the basic formula for fermentation
C6H1206 + yeast –> 2(C2H5OH) + 2(CO2) + heat
inoculation
the must with the cultured eyast gets the fermentation off to a fast start and gives the cultured yeast a substantial advantage over any wild yeast that may be present in the must
saccharomyces cerevisiae
the strain of yeast used for winemaking
length of fermentation of white wines
2-6 weeks
stuck fermentation
if the fermentation gets out of control and the liquid goes above 100F the yeast will likely die and fermentation will stop prematurely
the alcohol content of a dry white wine
12-14%
malolactic fermentation
a conversion process that can take place simultaneously with the primary (alcohol) fermentation or after the primary fermentation is complete. It is carried out by a particular strain of lactic bacteria that decomposes the sharp malic acid in the wine and ends up converting into lactic acid. Gives the wine creamy characteristics and buttery aromas
lees
the sediment of expired yeast cells and any other solid particles in the wine begin to sink in the bottom of the tank/barrel`
sur lie aging (on the lees)
as the wine rests on the lees, the dead yeast cells begin to decompose, potentially imparting a yeast aroma, creamy texture, and increased complexity in the wine
battonage
the sediment is stirred back up into the liquid to amplify the effects of sur lie aging
sulfur additiong
added to the wine if necessary to decrease the chance of microbial spoilage or browning in the finished wine
racking
involves allowing the suspended matter to settle to the bottom of the fermentation vessel and then carefully drawing the wine off the sediment and into a fresh container.
fining
a gentle form of clarifying a wine by adding a clarifying agent: egg whites, bentonite
filtering
invloves straining the wine through a barrier with very fine openings in order to trap any particulates over a certain size
aging wine in oak barrels
allows a slow oxidation that changes the wine and adds complexity
blending
shortly before bottling many different vats of wine may be blended together to make a finished product. It is used to develop complexity, balance or create a particular type of finished wine.
cold stablization
to prevent wine diamonds from forming in the consumers refigerator the wines must be chilled around 25F and then held at this temp for 1-3 weeks racking the wine away from the precipitates
red wine crushing and destemming
this process is done in order to break the grapes, free the juice, and allow the yeast to begin working
maceration
during red wine fermentation the skins remain in contact with the juice, the red and blue pigments are extracted out of the skins and into the darkening juice, along with tannins and flavor constituents
the cap
the carbon dioxide that is continuously produced during fermentation forms bubbles that push the grape solids and skins to the top of fermentation vessel in a fairly dense and compact mass
4 most common methods of cap mgmt
- punching down
- pumping voer
- rack and return
rotofermentation
pushing down
physically pushing the cap down into the juice
pumping over
pumping juice from the botttom of the tank and spraying it over the top of the cap
rack and return
also known as délestage this is sort of an extreme form of pumping over in which the fermenting juice is drained into separate holding tank before it is returned to the original tank by spraying it over the now sunken cap
rotofermentation
a process that occurs in a specialized fermentation vessel that either rotates on its own or contains an inner paddle that mixes the fermenting must. this eliminates the need for punching down or pumping over
extended maceration
the new wine may be allowed to remain in contact with the grape skins for several days to several weeks or even longer after fermentation is complete
Malolactic Fermentation in reds
in most reds high acidity is unnecessary so the added complexity is a plus. It results in a more microbially stable wine as some spoilage bacteria will attack malic acid
polymerization
the slow infusion of oxygen that seeps through the wood and into the red wine will help the tannic molecules combine with each other
variations in oak barrels
- new barrels add more flavor
- largre barrels have less of an effect than smaller barrels
carbonic maceration
also known as whole berry fermentation. it involves enzymatic fermentation that requires neither yeast nor bacteria. It occurs in whole, unbroken grapes in the absence of oxygen. primarily known for making Beaujolais Nouveau a light red wine from the Beaujolais region of france
vin gris
the most common method for making a rosé that involves limited contact between the skins and the juice so that only a degree of color is extracted from the grape skins and makes it into wine.
saignée
method of rosé production where red grapes are crushed, destemmed and vatted anywhere from several hours to several days. Next a certain amount of the juice is run (or bled) to make rosé
direct press method
rose production method where the grapes either destemmed or whole clusters are crushed and pressed at the same time resulting in very pale pink juice which is then fermented
ways to make sweet wines
- botrytis cinera (noble rot)
- late harvest
- dried grapes
- freezing
geography
Latitude Elevation Topography Aspect Proximity to water
soil
Chalk, clay, sand, gravel, limestone
water & air
Control vines desire to grow – vigor
Rock and slate act as heat collectors
cellaring
Once received by the buyer, bottles should be stored: At a constant 55º Free from excessive light At 60 -75 % humidity On their side
