Vinification 2 Flashcards
Volatile Acidity
of a wine is its total concentration of volatile acids, those naturally occurring organic acids of wines that are separable by distillation. Wine’s most common volatile acid by far is acetic acid(more than 96%), which is why it is used as the routine measure of volatile acidity (VA). A few other acids such as formic, propionic, succinic, and lactic, normally present in trace amounts in wines, are also volatile. The EU limit for VA (expressed as acetic) is 1.2 g/l for red wine and 1.08 g/l for white and rosé.
Acetic acid, in small amounts, is a by-product of the normal action of yeast in grape juice. However, the major source is the action of a group of bacteria known as acetobacter which require oxygen for their growth and survival, and cause a reaction between the alcohol of the wine and the oxygen to produce acetic acid. Very low concentrations of acetic acid, below 0.2 g/l, do not affect the taste adversely. Increasing concentrations change the taste of the wine, however, from added complexity and fruitiness to a frankly vinegary flavour at levels much above 1.5 g/l. Most everyday wines are very low in acetic acid but some red wines may be excessively acetic. A few fine wines, usually mature reds in bottle, are rich enough in body, tannins, and alcohol to bear low concentrations of acetic acid that are sometimes said to lift the flavour, although they would probably be even better without the VA.
It is not the acetic acid itself that causes changes in the aroma but the esterknown as ethyl acetate, the reaction product of acetic acid and ethanol.
Exposure of wines to air in the presence of acetobacter starts the process of vinegar production, although if exposure to air is limited the wine will probably not be spoiled.
It was the research work of Louis pasteur, trying to find a reason for the spoilage of so much burgundy shipped to England, that resulted in the discovery of acetobacter. It also resulted in the discovery that yeast is responsible for the conversion of grape sugars to wine.
Cold Soak/ Cold Maceration
The contents of the fermentation tank are cooled to delay the onset of fermentation and kept in this state for up to a week. This is a gentle approach to extract material from the grapes into the liquid that surrounds them. The technique was initially taken to extreme by the addition of a large foes of Sulfur dioxide, which increased the extraction properties of the liquid.
What year was biodynamics created by Dr Rudolf Steiner?
1924, he died the following year
Picking Options
“Hand Harvesting isn’t always the best for quality”
- Night, Cool and quick transfer to the winery can be beneficial for? Mechanical Harvesting
- 4 Benefits of hand Harvesting: Select- check rot, ripeness and quality, Gentle- can be placed gently into small containers, Whole Bunch- carbonic maceration or whole bunch for Chardonnay, or part of legal requirements (ie Champagne), Physical requirement of vineyard- ie Hills and steep cliffs of vineyards
- 4 Machine Advantages: Night- done when it is really cold, Quick- to he winery quickly to prevent oxidation, More Cost Effective, Scare Labour- ie Australia, can be the only cost effective option.
- Modern harvesters now have sorting options which can be more through than some labour that may not be as trained in picking the best berries
Common Faults
Fault- Internal, Taint- External to the process, Fault- A contributor to the wine (SO2, etc) are in excess from normal wine characteristics
Oxidative Faults
- Oxidation, Acetaldehyde, Voltatile Acidity, Ethyl Acetate
- How to avoid these: Protective handling, Topping up barrels, gas blanketing, effective SO2
Reductive Faults
H2S (stressed yeast, stuck ferments- cause; lack of nutrition, unclarified musts)
Elemental Sulphur- coming in from the vineyard: can be avoided by in whites by settling via centrifuge of must
Mercaptans or Thiols- H2S and ethanol forming together
Dimethyl Sulfide (DMS)- “cooked corn”, often from bottle age
Additive Related Faults
Excess SO2- from additions
Diacetyl- from lactic acid bacteria
Geranium- from Dornoch acid and lactic acid bacteria
Microbiological Faults
Brettanomyces- can be formed by: 4- ethyl- phenol; band- aid, barnyard; 4- Ethylguaiacol- bacon, smoke, cloves, spice, 4- Ethylcatechol, Isovaleric Acid- sweaty sock, rancid
Taints
- Cork type taints- TCA/ TBA can come from environmental situations (ie Shipping containers, wooden pallets, wooden barrels), Earthy- type taints: Geosmin, Moulds (ie Botrytis), Smoke Taints- Guaiacol (smoke taints, high smoke oak), Heat Damage- Maderisation (premature oxidation), Light Struck, Ladybird Taint, Naturally Occuring flavour can be considered a taint- Eucalyptol (gum leaf aroma), Rotundone (found in cool climate Shiraz),
- CAUSE: Poor hygiene; too much or too little O2 or SO2; too longer maceration pre- or post- ferment; faulty fining, filtration or stabilisation; Dirty Barrels; Too long Barrel ageing; Poor corks; Poor Storage;
- Don’t forget that regular testing- tasting and/ or analysis is extremely important
Handling of Wine- Bulk
- Cost Effective
- Bulk wine shipping in the U.K. Has gone from 20% to 80%
- Environmental, Operational, Availabilty, Effect on wine quality- ie Oxidation and Reduction during transport, contaimination, or leaks- these are issues to think of about when writing an essay
- There are two ways to ship in bulk- stainless steel ISO containers or flexitanks
- Ullage, OXygen Transmission Rates, Cross Containination, Dissolved CO2, Flexitank, ISO Tank, Insulation, Taint and Spoilage, Leaks, Gas Cover- Word cloud from Wine Tutor. TV
Maturation
- Depends on money as to maturation technique used
- Can have a significant impact on quality.
- Essays on Oak pop up all the time in the MW exam. Students should be aware of- variables (origin, format, factoring process, grain size, toast level, water bent and age), other types of woods used (ie acacia),
- In both red and white oak plays a role in oxiganisating, stabilising and improving,
- Potential risks of length in oak (ie over exposure to oak- drying out, microbial spoilage, over sensory impact,
- The role of micro- oxygenisation is important to understand as well.
- Chips and powder- the use for cheap wines
- White wine: lees and malo must be understood, benefits of barrel fermentation- Chardonnay: better intergration of oak and fruit, different Barrels give wine makers more choice when it comes to blending wines, lees- keep the wine fresh and also reduces the risk of malo driven dyacetal
- Other Maturation vessels include: inert tanks- stainless, glass epoxy or concrete, as well as the growing trend of clay, ceramic or eggs, amphorae, quevri- aware of cost, suitable winemaking techniques, thermic qualities, oxygen transmission rates, sensory impact
- The bottle itself should be considered as well- vintage port, champagne, vintage Barolo, etc
- Tag Cloud for an essay on maturation: Stainless Steel, Glass Fibre, Epoxy, Amphora, Qvevri, Clay, Concrete, Oak, Barrels, Barrique, Hogshead, Puncheon, Foudre, French/ American Oak, Slovenian, Hungarian, Grain Size, Toast, Seasoning, Lactones, Micro- oxygenation, Micro oxidation, Stavs, Powder, Lees, Battonage, Settling, Racking, Oxidative, Reductive, MLF, temperature, time, Legal Requirments, labour, access, cost,
Ycoden-Daute-Isora
Complicated name from the Guanche pre-Hispanic times, for the most ancient, but recently denominated, wine region in the Spanish canary islands. It is centred on the town of Icod de los Vinos, where wine has been made since the Spanish conquest in the 15th century. It now produces some of the best dry whites in the islands, from listán Blanco (palomino) and, increasingly, from the much more distinctive vijariego and marmajuelo grapes. The region has 1,350 ha/3,300 acres under vines. In the 1990s, coastal vineyards were consistently uprooted and replaced by inland vineyards at much higher elevations on the verdant volcanic slopes.
Valle de la Orotava
Denominated wine region with just under 1,000 ha/2,470 acres of vines on the lush northern flanks of Mount Teide on Tenerife in the Spanish canary islands. Much improved reds, whites, and rosés are made from indigenous varieties and exported by the likes of Suertes del Marqués.
Valle de Güimar
Denominated wine region of just under 1,000 ha/2,470 acres at up to 1,400 m/4,593 ft occupying a valley in the dry south-eastern part of Tenerife in the Spanish canary islands. A few tiny wineries, technically improved with eu subsidies, make surprisingly distinguished wines from the white listán Blanco grape, but in such small quantities that they are hardly known even on the island.
Ucles
Promising Spanish do in the Cuenca province of castilla-la mancha.
Txakoli
Usually white wine made in Spain’s basque country, known as Chacolí in Castilian. Like vinho verde it is strongly Atlantic influenced and is usually sold young, very slightly sparkling, and low in alcohol. A century ago over 1,000 ha of vines stretched from Bayonne to Bilbao, but after phylloxera ravaged the region, few vineyards were replanted. With cool summers, and an annual rainfall of 1,500 mm/58 in, this is hardly ideal grape-growing country. The high trained Hondarribi Zuri white grape variety, which accounts for 85% of Txakoli, traditionally produced thin wines, but quality noticeably improved during the 1990s. Hondarrabi Beltza makes light reds for local consumption.
Getariako Txakolina is the principal appellation yet is still one of Spain’s smallest do regions and a matter of considerable pride to those few basque farmers who stubbornly refuse to give in to the elements and have even increased their vineyards to reach 84 ha/201 acres on the rocky Biscay coast west of San Sebastian (see map under spain).
Bizkaiko Txakolina is an even smaller DO region with just 60 ha/144 acres of vineyards scattered in Vizcaya province around the main city of Bilbao. The predominance of folle blanche grapes makes for more acidic and herbaceous wines than in Getariako.
Arabako Txakolina is the newest DO for Txakoli and comprises just 50 ha of vineyards in the Ayala valley near Vizcaya. Hondarribi Zuri and Hondarrabi Beltza are the main grape varieties, while Petit Manseng, Petit Courbu, and Gros Manseng are also permitted.
Tierra de Barros
Spanish wine zone. See extremadura.
Tacoronte- Acentejo
do wine region of 1,730 ha/4,270 acres of vines on the west-facing slopes up to 800m in the north east of the volcanic island of Tenerife in the canary islands. Tacoronte-Acentejo produces red wines made predominantly from the dark-berried listán Negro and Negramoll grapes. The fertile volcanic soil imparts a peculiar character to these improving wines.
Sierras de Malaga
Spanish do created in the early 21st century as effectively a subappellation of málaga to include a number of relatively new vineyards producing dry, unfortified wines, some in a subzone known as Serranía de Ronda around the inland town of Ronda, of which F. Schatz and Cortijo de los Aguilares are probably the best producers.
Ribera Del Jucar
promising Spanish do in the Cuenca province of castilla-la mancha whose first vintage was 2003.
Ribera del Guadiana
Is the chosen name for a single denominated zone encompassing about 26,000 ha/64,000 acres of vineyards in Spain’s extremadura region. The do, awarded in 1998, includes such well-known areas as Tierra de Barros. The autonomous Extremadura government is actively encouraging the planting of international varieties and improvements in wine quality but the results have been slow in coming.
Ribeira Sacra
Growing Spanish do, created in 1996. It is the only galician region specializing in red wines, from the mencía grape, and some less well-known local varieties, together with some whites from Godello and Albariño. Since 2005 the region has won growing acclaim, particularly in the United States, where its top producers Algueira, Guímaro, Dominio do Bibei, Raúl Pérez, Ponte da Boga, and Envínate enjoy a certain cult status.
Pla L Llevant
small (335 ha/800 acres) but thriving do on the Spanish island of mallorca.
Pla de Bages
small but growing catalan wine region north west of Barcelona in Spain with just over 550 ha/1,300 acres under vine. Grape varieties are similar to those in neighbouring penedès, with international varieties such as Merlot and Cabernet Sauvignon planted enthusiastically during the 1990s.
Mondejar
denominated wine zone in northern Castilla-La Mancha, Spain, near Guadalajara, created in 1996 and producing table wines of modest distinction. Tempranillo is the main variety in the 2,100 ha/5,000 acres of vineyards.
Méntrida
Spanish town and wine zone south west of Madrid in castilla-la mancha traditionally producing robust red wines from garnacha grapes. The one producer who is making high-quality wine in this part of Spain, Marqués de Griñon, grows cabernet sauvignon, chardonnay, syrah, and petit verdot in his vineyard at Malpica de Tajo, which used to be just outside the denomination but has now been incorporated within it. He spurned the opportunity to jump rank from what was then the lowest to the local do and was rewarded in 2002 with his own single-estate DO (see vino de pago), Dominio de Valdepusa. Meanwhile, a small number of producers in Méntrida proper and in its mountainous northern area, part of the GREDOS region, began making significant progress with local Garnacha and Albillo Real grapes as well as with Syrah and Cabernet Sauvignon.
Manchuela
One of Spain’s newest wine regions, granted a do in 2000, with vineyards totalling more than 55,000 ha/130,000 acres (although only 3,700 ha of these were registered for DO wines in 2014) on the eastern border of castilla-la mancha, straddling Cuenca and Albacete provinces. This is the home of the Bobal grape, which is mainly used for rosés and unoaked young reds, with Tempranillo growing in importance for oak-aged reds. At least one private estate was making a name for itself by adapting Syrah to the local clay-limestone terroir and making blends with the best local varieties Monastrell, Garnacha, Garnacha Tintorera (alicante bouschet), and Bobal. The white Macabeo also produces very drinkable fragrant whites in northern Albacete, while the local Albilla de Manchuela has been rediscovered as a good quality grape. Overall, this high plateau, which reaches an elevation of more than 1,000 m/3,280 ft in western Cuenca shows great potential but has mostly lacked the investment required to develop it.
