Grape Berry Flashcards
What are the four steps of ripening?
Herbaceous phase
Veraison
Maturation
Sur-maturation
At which point in ripening do many of the desirable flavour compounds accumulate in the grape?
Just after the increase in sugar formation slows down; max reached then decline during sur-maturation
What are the main constituents of grapevine berry juice?
Water (80%)
Sugars and other carbs (20%)
Acids (1%)
Phenolic compounds (0.1%)
What mineral salts are present in grapevine berry juice and what do they do?
Mainly potassium and calcium salt
Buffer (mask) effect of acids
What is the effect of pectins?
High concentrations make it difficult to extract and.or clarify grape juice; broken down by pectolytic enzymes during grape processing
Gemurztraminer and Viognier are high in pectins
What are the main acids in grapes?
Tartaric and malic
Can also contain low levels of citric, ascorbic and acetic acids
What types of grapes may have high malic acid?
Those picked early or ripened in very cool conditions
What are phenolic compounds?
Group of chemical compounds that affect a wine’s colour, texture, astringency and bitterness
What are anthocyanins?
Phenolic compounds the give red wine colour
Found in pulp directly underneath skins of black grapes
What are tannins?
Large phenolic compounds that determine body and astringency of wine
Antioxidant, preservative
Precursor to aromatic compounds when wines are aged
What affects the chemical composition of grapes?
Grape variety
Environment: climate, soil
Viticultural management
Seasonal variation
What is the herbaceous phase?
From formation of berry until veraison
What is veraison?
Marks beginning of berry ripening when grapes change color
Berry stops photosynthesizing (all sugars that accumulate after are photosynthesized by the leaves)
What is maturation?
Grapes swell, sugar concentration increases, acidity decreases
Lasts for 40-60 days
At physiological maturity berries attain max diameter and sugar
What is sur-maturation?
When berries are left on vine and become over-ripe
What are the main criteria when selecting vines?
Adaptation to climate
Resistance to disease
Adaptation to soil conditions
Economic characteristics
What are American hybrids bred with vitis vinifera?
Concord, Black Hamburg, Clinton
What is the group name “teinturier”?
Grape varieties that give deep red juice on pressing because they have anthocyanins in pulp as well as skin (e.g., Alicante Bouschet–cross between Petit Bouschet and Grenache)
What is Petit Bouschet?
Cross between Aramon and Teinturier
What is mass selection?
Traditional method of selecting vines
Passing through vineyard before harvest and marking out best plants from which to take cuttings during the winter
What is clonal selection?
Selecting plants originating from a single parent with desirable qualities
What is layering?
Vine canes are buried in the ground then separated from parent once they establish their own roots
Used in Argentina and in Champagne for Bollinger’s “Vieilles Vignes Francaises”
What is vitis vinifera sativa?
Vitis vinifera subdivision
Cultivate vine with 5-10,000 wine-producing varieties (including all classics)
Selected to be hermaphroditic for good fruit set and for relatively large fruit
What is vitis vinifera silvestris
Vitis vinifera subdivision
Wile European vines
Not usually hermaphrodite
Mostly eliminated by phylloxera
What is vitis labrusca?
Wild vine species found in north eastern US
Produces strongly flavoured, dark berries; described as “foxy”
Common parent in American hybrids (Conford)
Not often used as parent for rootstock production
What is vitis riparia?
Wild vine species on river banks and alluvial soil in central-eastern parts of North America
Used principally as a rootstock
Low vigour, surface rooting, encourages early ripening, good resistance to phylloxera, suffer from chlorosis in chalky soil
What is vitis rupestris?
Wild vine in light soils in southern center US
Used primarily as rootstock
Vigorous, deep rooting, good resistance to phylloxera, suffer from chlorosis
What is vitis berlandieri?
Wild vine on chalky slops in southern US and Mexico
Vigorous, deep rooting, high resistance to chlorosis, cuttings have poor ability to root
Often hybridized with riparia and rupestris to produce lime-resistant rootstocks that growth and root easily with different levels of vigour
Why is Chardonnay an ideal component in the blend for quality sparkling wine production?
Supplies acidity, elegant light body, citrus and green fruit
Why does the winemaker have to be extra vigilant with Syrah/Shiraz?
It is prone to develop reductive (mercaptan) flavours
Why was Viognier traditionally co-fermented with Syrah in Côte Rôtie?
To increase wine colour and colour stability
Which of the Muscat varietals is know to produce more complex and elegant wine styles?
Muscat Blanc a Petits Grains
What is one of the distinguishing similarities between Gewurztraminer and Pinot Gris?
Pink grape skins
What is negative attribute of Pinot Gris/Grigio?
Too many uninteresting, dilute, neutral examples
What varieties are sometimes locally referred to as Riesling?
Crouchen Blanc, Welschriesling, Semillon
What is a negative attribute of Riesling?
Still under appreciated by most wine consumers
Is Gewurstraminer blended?
Rarely but can contribute fruit to a multi-varietal blend and can be blended with other aromatic varieties (Muscat, Riesling)
What is the grape of Muscadelle and Muscadet?
Melon de Bourgogne
What type of wines does Muscat Ottonel make and where?
Dry and off-dry fruit whites in Alsace and Central Europe
Why does Chenin Blanc have to be picked in tries (several passes through vineyard)?
Because it ripens unevenly and need to avoid having leafy and tropical aromas in same wines
What is the perception of Chenin Blanc?
Under appreciated and unfashionable
What is Fume Blanc?
Oak-aged Sauvignon Blanc from the US
What kind of diseases is Sauvignon Blanc susceptible to?
Black rot and powdery mildew
What is the perception of Semillon?
Under appreciated and unfashionable
What is a negative attribute of Semillon?
Can lack aromas and acidity in some conditions
In such cases it is blended with SB
Can Viognier be oaked?
Yes, but flavours are delicate and can easily be lost when too much oak is used
Can Viognier be aged?
No, it does not improve with age
What does Viognier from over-ripe grapes taste like?
Over-alcoholic and bitter
What are other names and subvarieties of Trebbiano
Other names include Procanico, Ugni Blanc Subvarieties are: Trebbiano di Toscana Trebbiano di Soave (actually Verdicchio) Trebbiano Romagnolo Trebbiano d'Abruzzo (may be Bombino)
What does its high-acid, low-alcohol qualities make Trebbiano/Ugni Blanc ideal for?
Brandy (Cognac, Armagnac)
What is Trebbiano blended with?
Local varieties in Gascony and Provence
Garganega (Soave)
Malvasia (Frascati)
Verdelllo, Grechetto (Orvieto)
Why is Pinot Noir ideal for sparkling wine?
It takes up autolyic flavours well and supplies body and length
What are negative attributes of Cabernet Sauvignon?
Can be austere and hollow on its own
Ripens late and can be difficult to ripen fully
Low yields despite high vigour
What is a positive attribute of Cabernet Franc as compared to Cabernet Sauvignon?
It can give CS like structure and flavours but can ripen in cooler, wetter conditions
What is the “international” style for Merlot?
Deep colour, full body, high alcohol, baked/jammy fruit often supported by toasty oak
What are negative attributes of Merlot?
Can be rather bland and lacking structure
Early budding so prone to spring frosts
Prone to coulure
If Petit Sirah is on a label, what is it?
It is not Syrah; it is Durif
What is the name for Grenache in Sardinia?
Cannonau
What is a Tempranillo from Rioja like?
Ripens with high levels of malic acid so MLF by-products (soap and creaminess) distinctive
What are some synonyms for Tempranillo?
Tinta Roriz (Douro, Dao0, Aragonez (Alentejo), Ull de Llere (Catalunya), Cencibel (Valdepenas) and Tinta del Pais/Tinta de Toro (Ribera del Duero/Toro)
What is Nebbiolo blended with?
Barbera, Bonarda (in Piedmont)
What does Barbera contribute to a blend?
Deep colour and high acid
What is Sangiovese blended with?
CS, Syrah, Merlot (Tuscany)
What are positive attributes of Sangiovese?
Good quality potential
Traditional
How does Zinfandel/Primitivo tend to ripen?
Unevenly, so shrivelled and unripe grapes may be on the same bunch
What are examples of crossed varieties?
Muller-Thurgau (Riesling x Madeleine Royale) Ruby Cabernet (Carigan x CS) Pinotage (Pinot Noir x Cinsault)
What is a a commonly suggested parentage for Muller-Thurgau?
Riesling x Silvaner
What is Muller-Thurgau commonly blended with?
Riesling, Silvaner, Kerner (in Liebfraumilch) Morio Muskat (aromatic medium whites)
What are positive attributes of Ruby Cabernet ?
Can withstand hot weather, is drought resistant
Produces high yiels
What is a negative attribute of Pinotage?
Reputation for isoamyl acetate (paint) smell remains despite improvements in wine making
What are examples of hybridized varieties?
Seyval Blanc (Seibel 5656 x Seibel 4986) Rondo ((Precoce de Malingre x vitis amurensis) x St. Laurent) Vidal (Ugni Blanc x 4986 Seibel)
What is an wine making technique that some producers are using to improve their Seyval Blanc?
Ageing in oak barrels leading to fuller, soften wines
Why is Seybal Blanc outlawed in the EU for quality wine production?
Because there are some non-vinifera genes present in the variety
How is Rondo like Tempranillo?
Pronounced Malolactic (creamy) notes
What are positive attributes of Rondo?
Early ripening, high resistance against frost and disease
Produces intensely coloured ruby-red wines making it an ideal blending component (Dornfelder, Pinot Noir)
May be used in quality wine production because produces vinifera-like wines
What is Ugni Blanc used as the base of?
Canadian ice wine (thick skins make it suitable for sweet, law harvest (non-boytrytised) wines and ice wine)
