Terms & Definitions Flashcards
Sedimentation
A form of clarification. It is also sometimes called ‘settling’. Suspended solids in must or wine are left to fall over time with gravity.
Can occur prior or post fermentation
Centrifugation
A machine that comprises a rapidly rotating container which uses centrifugal forces to separate solids from liquids
Bentonite
A form of clay that adsorbs unstable proteins and unstable colloidal coloring matter.
Used in the winery as a fining agent.
Can be used to fine must as well as wine
Main shoots
The primary unit of wine growth. Major structures, which are collectively called the canopy, are the buds, leaves, tendrils, lateral shoots, and inflorescence/grape bunches.
The main axis of the shoot transports water and solutes to and from the difference structures. Stores carbohydrates.
Solutes
Substances that dissolve in a liquid to form a solution, ie include sugars and minerals
Canes
When the leaves fall from the vine and the green shoots lignify (become woody, rigid and brown)
Occurs in the late summer
Buds
The structures of the shoot that form between the leaf stalk (petiole) and the stem. They contain all the structures in miniature that will become the green parts of the vine
2 main types are compound buds and prompt buds.
Compound buds or latent buds
Future season’s buds
Produce the shoots in the next growing season. Form in one growing season and break open in the next growing season.
Prompt buds
Current year’s buds
Form on the primary shoot and produce lateral shoots. Form and break open in the same growing season.
Lateral shoots
Secondary shoots that grow from the prompt buds. They are smaller and thinner than the primary shoots
Main function: allow the plant to carry on growing if the tip of the primary shoot has been damaged or eaten
Often produce inflorescence (ex. Pinot Noir)
Tendrils
Pair of the shoot that can help provide support
Leaves
The main site of photosynthesis
Transpiration
The process that draws water and nutrients from the soil up through the wine to the leaves. Occurs as the water diffuses from the leaf
Stomata partially close if the vine is water stressed, which can help conserve water, but limits photosynthesis by presenting CO2 from entering the vine
Inflorescence
A cluster of flower on a stem => becomes a bunch of grapes at fruit set
Usually between 1-3 on a shoot
Grape bunches
Fertilized inflorescence
Tight bunches are more prune to fungal disease due to the increased likelihood of grape-skin splitting and lack of air flow throughout the bunch
Conventional, modern winemaking
Builds on the scientific understanding of the processes which convert grape must into wine.
-Influenced by Louis Pasteur’s work (1860s) on identifying bacteria and yeasts
Includes
- Temperature control
- Use of additives and/or processing aids of many types
- Manipulations
Goal: produce stable wines that reliant display fruit character and have no faults
Organic winemaking
Making wine with certified organically-grown grapes and complying with rules that restrict certain practices from being performing during the winemaking process
Ecocert
Certification agency that issued a full list of allowable additives and processes allowed in organic winemaking
Biodynamic winemaking
Made from certified bio dynamically grown grapes
Demeter International
Main certifying association for biodynamic wines
Natural winemaking
Reject modern interventions in favor of artisan practice: “nothing added, nothing removed”
No agreed/certified definition. Usually refers to wines made with the fewest possible manipulations (ie low-intervention winemaking)
Natural winemaking certification organizations
Vin methode nature - France; first nationally recognized certification
L’Assoication does Vins Naturels - France
VinNatur - Italy
Amphorae
Giant clays pots that age wine underground
Oxidation reactions
The reactions caused by the presence of oxygen that create products that then go on to react with many must and wine compounds
Thiols
A category of aromatic compounds that are released during fermentation that give the box tree aromas in Sauvignon Blanc (ex. 4MMP)
They break down the presence of oxygen => can lead to the loss of fruitiness
Book sites thiols as an example of an aroma precursor present in grape must that creates aromas due to the fermentation process
Terpenes
A category of aromatic compounds that are released during fermentation that give fruity and floral aromas to wine. Ex’s Linalool and geraniol => grapes aromas/flavors in Muscat
Acetic acid
A byproduct of fermentation that gives vinegar it’s characteristic odor
Methoxypyrazines
Occur in Sauvignon Blanc that give a grassy, green pepper aroma
Book sites as examples of aromatic compounds found in grapes
Rotundone
Occurs in Syrah and Gruner Veltliner that produce a pepper aroma
Book sites as an example of an aromatic compound that is found in grapes
Esters
Compounds formed by the reaction of certain acids and alcohol, a majority of which are created through the action of yeasts in the fermentation process
Responsible for the fresh and fruity aromas => essential in young wines
Book sites as examples of aromas that are bo-products if the fermentation process
Isoamyl acetate
And ester that gives the aroma of banana (when highly concentrated) - Ex. in Beaujolais Nouveau
Others produce flavors of apple, pineapple, etc
Ethyl acetate
An ester that gives off the smell of nail polish, ie what causes volatile acidity in high quantities
Acetaldehyde
An ester that occurs in wine due to the oxidation of ethanol; also called ethanal
Nutty, apple and even a stale smell (often seen as a fault); however, gives Fino sherry it’s distinctive smell
Diacetyl
Produced during fermentation, esp malolactic conversion => buttery aroma
Vanillin
An organic compound
Aromas of vanilla
Can be derived by aging in new oak barrels
Eucalyptol
A monoterpenoid (a colorless liquid), which can be volatized from eucalyptus trees by heat and absorbed in the waxy layer of the skins of grapes in nearby vines
Glycerol
Compound derived from the sugar in grapes; contributes smoothness and perception of fullness in body. Slightly sweet taste
Ex. Botrytis wines and wine made by carbonic maceration
Phenolics
A group of compounds that occur in grapes, esp in the skins, stems, and seed, which include anthocyanins and tannins
Have an anti-oxidative effect
Anthocyanins
Color pigments responsible for the red or blue tints in red and rose wines
Tannins
Compounds that bind with proteins in the mouth, giving a drying sensation on the palate
Ullage
The headspace of air between the wine and the top of the container
Inert gases
Chemically inactive gases that do not react with compounds in the wine.
Ex. Nitrogen, carbon dioxide, and argon
Sulfur dioxide
A preservative that is almost universally used in winemaking. 2 main properties:
1) Anti-oxidant
2) Anti-microbial
Anti-oxidant
Reduces the effects of oxidation by reacting with the products of oxidation reactions => can’t oxidize further compounds
Anti-microbial
Inhibits the development of microbes such as yeast and bacteria
Bound SO2
Proportion of must or wine that has dissolved SO2 that has reacted with compounds in the liquid
It’s infective
Against oxidation and microbes
Free SO2
Proportion that is not bound. Majority of free SO2 exists in a relatively inactive form
A small proportion exists as molecular SO2, which is the most effective against oxidation and microbes
A greater proportion of free SO2 is in the molecular form at lower pH levels
