Wine Making Flashcards
Components of a grape
75% pulp
20% skin
5% seeds (2-4 seeds)
Water
Sugar
Pulp (acids, minerals, pectin compounds, vitamins)
Skin (aroma, flavor, color, tannin)
A high ratio of skin to juice promises lots of concentrated aroma, flavor, and structure
Components of wine taste
Alcohol Acid Tannin Fruitiness Dryness Sweetness
Hang time
Time it takes grape to ripen
Long = preferable, components of grape other than sugar (e.g, tannin) to reach physiological maturity
Over ripe = bad, only want long hang in pursuit of ripeness
Alcohol in wine
Components: yeast + sugar —> alcohol + Co2 + heat + byproducts
Glycerol = byproduct, gives wine sweetness and may contribute to slightly viscous, mouth-coating texture
More alcohol, fuller body, weighty on palate
Hot = wine with too much alcohol that when you smell, you get a burn
- masks flavor of wine
- overly ripe, similar to raisins called “overcooked”
Can balance alcohol with tannin, acidity, fruit
Hard to be over 15% and still good
Acidity
Ripening: acid content decreases from 3% to <1%, sugar content increases from 4% to >24%
Harvest when optimal balance between sugar and acid
Acidity - liveliness, snappiness, freshness, thirst quenching
Wines that lack acidity cannot age
In warm regions, grapes lose natural acidity, so winemakers “adjust” acid by adding 2-3g of tartaric acid per liter
Types of acidity: harsh, round, candied, volatile (acetic acid formed by bacteria during or after fermentation)
Tannin
Plants build tannins for protection, preservation and defense
Part of complex compound called phenols
Located in: grape skins, seeds, stems
Cabernet Sauvignon - lots
Pinot noir - relatively little
Structure - sense that wine has an underlying architecture
Live longer without tannins
Tannin taste: bitterness; espresso or dark chocolate
Tannin feel: astringency or dryness
As grapes ripen, sugar builds, acidity drops, tank s mature —> seeds turn nutty brown as tannin ripens
Tannin molecules in wine are hugely attracted to protein in saliva; saliva bound by tannin molecules can no longer lubricate the palate, and as a result, mouth tissues rub against one another, causing your palate to feel dry
Perception of tannin can be changed by food
Fruitiness
WB - 14
- Propsensity of a wine to display ripe, fruitlike aromas and flavors
- Most marked in young wines
- Gewueztraminer and gamay are characteristically very fruity
- Fruitiness is often confused with sweetness, but the two are distinctly different
Dryness and sweetness
WB - 15
- Port: generally has approximately 8% residual sugar
- Sauterns: 10-15% residual sugar
- Sweetness: can be a goal, as in dessert wines, or a counterpoint, something used in small amounts to create overall balance and harmony
Attributes of wine greatness
WB - p. 4-8
- Distinctiveness
- Balance - Characteristic a wine possesses when all of its major components (acid, alcohol, fruit, and tannin) are in equilibrium; Integration - unique and stunning character that comes from the synthesis of the independent parts
- Precision
- Complexity
- Beyond Fruitness
- Length - Persistence of a wine on your palate, even after you’ve swallowed; the better the wine, the longer the length
- Choreography
- Connectedness
- Ability to evoke an emotional response
Terroir
WB - 17
Soil, slope, orientation to the sun, and elevation are all part of a vineyard’s terroir, as is every nuance of climate, including rainfall, wind velocity, frequency of fog, cumulative hours of sunshine, average high and low temperatures, and so forth
Climate
WB - 17-20
- Vines begin to grow when the ambient temperature reaches about 50 F
- Average daily temperature reaches 63-68 F (17-20C), vines will bud and then flower
- Mid-80s F (28-30C) - vine’s hit growth stride and flourish
- Microclimate - area around a vine that extends 6’ above the ground and about 3’ into the soil, below the ground
- Intense sun can cause grapes to lose considerable acidity through respiration, leading to flat, flabby wine, or cause hyperactive leaf growth, which shades the grapes and may lead to vegetal and other off-flavors in the wine
- At about 104 F (40C) sustained heat becomes intolerable for most grapevines
- Vigor: growth of leaves and shoots
Fruitfulness: number of grape clusters and size of grapes - Temperature swings: by delaying ripening, cool nights also extend the span of time from bud break to harvest, leading to better total physiological maturity
Flowering
WB - 18
- Flowering: only those flowers that become pollinated and “set” on the cluster become individual grape berries
- Up to 85% o fa vine’s flowers never set
- Cultivated grapevines are hermaphroditic
Rain
WB - 21
- Rain, especially just before or during harvest, is dreaded throughout the wine world; absorbed quickly through the roots, rainwater can bloat the grapes, diluting their flavors; rot or mildew can take hold; trying to pick grapes when the vineyard is a foot-deep in mud is challenging; hail is worse
Types of rocks
WB - 22
- Sedimentary rock: sandstone, clay, limestone, peat, lignite, coal, quartz
- Igneous Rock: formed from molten or partially molten material, most igneous rocks are crystalline
- Metamorphic: sedimentary or igneous rock that has been transformed by heat or pressure; example are marble and slate
Water & Frost
WB - 22
- Well-drained soils encourage the roots to burrow deeper into the earth, where they find a more stable environment of moisture and nutrients
- Vines with fully developed root systems can handle drought or other climatic difficulties better
- in the spring, right before flowering, vines need some water to jump-start growth –> flower swill not set properly, will not create grape berries
- Veraison: tie in summer when the grapes begin to change color
- After prolonged below-freezing temperatures, the entire vine and root system can die
Wind
WB - 23
A gentle breeze is almost always good (it cools the grapes and promotes air circulation as a guard against rot)
Soils
WB - 24,25
Fill all of the soil
Soil
WB - 27
- There are 5 main factors in the creation of soil: parent material, climate, topography, biota, and time
- size of soil’s particles: larger particles such as sand can be important for good drainage; smaller particles may help hold enough water to support the vine’s growth
- Soil is its color and ability to reflect sunlight or absorb heat
Rootstock
WB - 33
- Rootstock is the root system beneath the soil; and the rootstock has nothing to do with the variety of grapes produced
Organic Wine
WB - 35
- Made from organic grapes and, in addition, sulfites cannot be added to the wine
- Sulfites, natural antimicrobial agents, help prevent spoilage and act as a preservative
Vine spacing
WB - 35
- The closer vines are spaced, the more their roots may have to compete for the same soil, nutrients, and water
- If vines are too vigorous, this competition may be beneficial, acting to slow down the vines’ growth, limit the number of grape clusters produced, and bring the veins into a better balance
Red vs. White wine
WB - 38
- Red wine: juice is fermented with the red grape skins
- White wine: skins aren’t necessary to tint the juice (it’s already clear), plus the skins might add tannin; skins are quickly separated from the juice before the juice is fermented
Making dry red wine
WB - 38
- With grapes that already have a lot of tannin in their skins (e.g., cabernet sauvignon), stems can add excessive tannin and are generally removed
- Less-tannic varieties (e.g., grenache from the Rhone Valley or pinot noir from burgundy) can leave stems on to add tannin
- Slower fermentations often produce more complex and aromatic wines
- Unattended, the skins will remain at the surface of the liquid, pushed from underneath by the tremendous pressure of the CO2 for as long as fermentation continues
- During fermentation, the temperature of the must rises to 60-85 F (16-29C)
- Winemaker does not want temperature to rise above 85F because higher temperatures will burn off (volatize) delicate aromas and flavors of the wine
- Separate from skins for good - wine is drained off to begin aging; this wine is free run - the best wine
Must
Soupy mass of crushed grapes, juice, skins, pulp, seeds, and possibly stems
Malolactic fermentation
Process critical to red wine’s softness and microbial stability
Racking
Process of allowing solids to settle to the bottom of the vat or barrel, then pouring of drawing the clear wine off
Fining
helps remove excessive tannin, thus hopefully, making the wine softer and less bitter, and improving it’s balance
- Choice of fining agent to use is important
- Each fining agent is made up of different-size protein molecules that attach themselves to different things
Filtering
- Helps to stabilize a wine microbiologically and helps to clarify it by removing suspended particles
- Excessive filtering, however, also removes desirable particles and thus strips the wine of some of its flavor and aroma
Aging
- Best red wines in the world always experience both barrel (oxidative) and bottle (reductive) aging
Making white wine
- Much effort is made to keep the fermetning juice cold (again, the idea is to preserve freshness and aroma)
- Ferment at 50-65 F (10-18 C)
- During barrel fermentation, the barrel is filled about 3/4 full to prevent the wine from foaming over
- As the wine ferments, the temperature raises to 70 F(21 C) or more
- Some fresh fruit aromas and flavors are sacrificed, the yeasts help pull toasty, sweet, vanillin flavors from the wood, creating the barrel-fermented style
Malolactic Fermentation (ML)
- Months-long process
- Carried out by bacteria (Oenococcus oeni)
- bacteria convert the malic acid in the wine to lactic acid
- Goal: change the way the wine will feel on the palate
- During ML, a byproduct called diacetyl is produced that gives a buttery taste
- Winemaker can lessen the buttery flavor
- -> leaving the wine in the barrel for several days after the ML fermentation is complete, but before the wine is dosed with antimicrobial agent sulfur dioxide; yeasts remaining in the juice will metabolize the diacetyl
Barrels
- Oak flavors are extracted more gradually from tight-grained (narrow ring) oak trees; and these, as noted, always come from cool, dry forests
- Oaktree is generally harvested when it is 150-250 years old
- Split the oak into staves along natural grain lines, then air-dry the staves by leaving them stacked outdoors in a stave yard, exposed to air, sun, rain, snow, wind, fungi, and microbes for 2-4 years
- harshest tannin is gradually leached out of the wood
- After the barrel is built, it will be exposed to a fire again, this time to “toast” the inside; the fire carmelizes the wood’s natural carbohydrates, bringing out compounds such as vanillin, a molecule that occurs naturally in oak
- Since the mid-1990s, some American oak barrels have been made according to the traditional European method
- after 4 uses or so, a barrel is generally considered “neutral”
Role of Oak
- Phenols impart vanilla-like flavors, notes of tea and tobacco, and an impression of sweetness
- Oak chips, beans, and locks are added directly to the fermenting tank, either loose or enclosed in a giant mesh teabag; staves can be inserted into a frame that can be dropped into older barrels or suspended in stainless steel tanks
American Oak
- Heavier, denser, and less porous than French oak, also tends to be less tannic and have more pronounced vanilla and sometimes coconut-like flavors
French Oak
More subtle in terms of flavor, somewhat more tannic, and allows for slightly greater, but still gentle oxidation
Aging v. fermenting in oak
Fermenting: yeasts also interact with the wood; when the spent yeast cells (lees) are ultimately removed from the wine, a measure of the wood tannin (and wood flavors) may be removed with them
Age: may have more pronounced flavors than fermenting
Making off dry wine
- Fermentation is stopped, usually by giving the wine a small dose of SO2 (sulfur dioxide), which kills the yeasts before they have converted all the sugar to alcohol
Dessert wine grapes
- Picked when their sugar content is very high
- Picked, laid out on mats, and allowed to raisinate, thereby concentrating their sugar
- Permitted to freeze on the vine so that water can be separated from the sugary juice
- Attacked by the fungus Botrytis cinerea (noble rot of French Sauternes), which consumes some of the water in the grapes and helps more to evaporate, again concentrating the sugar
Chaptalization
The act of adding sugar to a low-alcohol wine before and/or during fermentation so the yeasts will have more sugar to convert to alcohol
