Describe Flashcards
To set out the characteristics
Describe 6 factors in the vineyard that affect temperature.
- latitude
- altitude
- slopes and aspect
- proximity to water
- winds
- characteristics of the soil
- clouds
- mist and fog
- diurnal range
Describe the function of the vine roots.
The roots are important for anchoring the vine and also for the uptake of water and nutrients. The roots are also a store of carbohydrates and produce hormones that have important functions within vine growth and grape ripening. In most cases, vines are grafted onto a rootstock.
Most of the vine’s roots are found in the top 50 cm of the soil, although vine roots have been found that reach over six metres down into the soil. Distribution of the main framework of roots is influenced by the soil properties, irrigation, cultivation and the type of rootstock. The water and nutrients are absorbed at the root tips, where the roots are actively growing.
Describe the effects of temperatures above 33 degree celsius on the vines’ ability to ripen grapes.
33 °C is reaching the maximum within the temperature range (18–33°C) for vines to ripen grapes. Temperatures above 33°C can lead to very hot, dry conditions that can lead to extreme water stress can cause photosynthesis to slow or stop and hence hinder sugar accumulation in this way. Extreme heat, especially when paired with dry conditions, can cause photosynthesis to slow or stop, slowing vine growth and grape ripening. In addition, water stress, which is typical in many hot regions, can also cause photosynthesis to slow down or stop due to the shutting of stomata to prevent water loss. The closed stomata limit intake of carbon dioxide, which is needed for photosynthesis.
Describe two regions that rely on the temperature moderating effects of ocean currents.
Vineyard areas in coastal regions can also be affected by ocean currents, which can have a marked influence on temperatures. For example, both the Willamette Valley in Oregon and Margaux in Bordeaux are located at approximately 45° latitude; however, the main grape in the Willamette is early-ripening Pinot Noir, whereas Margaux is capable of growing late-ripening Cabernet Sauvignon. The warmer climate in Bordeaux (average growing season temperature 17.7°C) is at least partially due to the Gulf Stream, which flows from the Gulf of Mexico and warms many European wine regions. By contrast, the west coast of North America, including Oregon, is cooled by the cold California current, which flows from the northern Pacific (average growing season temperature in Willamette Valley is 15.9°C). In the western USA, wine regions that are sheltered from the ocean influence, for example by mountain ranges, are much warmer and drier than those that are not.
Describe the result of low or high nitrogen levels in vineyard soils.
Too much nitrogen in the soil causes excessive vegetative growth, with sugars being diverted to the growing shoots and leaves rather than the grapes, hindering ripening. An excess of shoots and leaves in the canopy can cause shading of fruit and buds (with a number of consequences) and poor ventilation (leading to fungal disease) unless adequately managed. Too little nitrogen results in reduced vigour and yellowing of vine leaves. Grapes that have low nitrogen levels can also be problematic for fermentation.
Describe the importance of humus in vineyard soil composition.
Soil health describes the continued capacity of the soil to act as a living ecosystem that
sustains plants, animals and humans.1 It is related to:
* the structure of the soil: beneficial properties include good drainage, sufficient waterholding capacity, sufficient oxygen, the ability to resist erosion and to allow the roots of the vine to penetrate to sufficient depth
* the amount of organic matter and humus in the soil: decomposing organic matter supplies nutrients, and humus improves the structure of soil and its water-holding capacity
* the number of living organisms in the soil: earthworms and microbes break down organic matter into humus and inorganic nutrients that are accessible to the vine
* the total amount of available nutrients that the vine needs to grow successfully
Poor soil health can lead to problems with the availability and uptake of nutrients and water in the soil, and hence poor vine growth and ripening. Grape growers may have soil tests conducted when establishing the vineyard and then annually so that corrective measures, such as improving the structure of the soil or adjusting nutrient levels, can be taken.
Describe the types of herbicides used in vineyard management.
Herbicides are chemical sprays that kill weeds. There are three types of herbicides:
* Pre-emergence herbicides are sprayed before weeds establish. They persist in the
surface layers of the soil but are absorbed by the weeds’ roots and inhibit germination of young seedlings.
* Contact herbicides are sprayed on established weeds and kill the green parts of the weed that they contact, resulting in the death of the plant.
* Systemic herbicides are sprayed on established weeds and are taken in by the leaves. The herbicide travels up and down the weed in the sap and kills the whole plant.
Describe three ways that a producer in a region that does not allow irrigation could combat water stress in the vines.
Describe the conditions and symptoms of leaf spot.
Describe the effects of Leaf Roll Virus.
Describe how ethanol contributes to the overall perception of wine.
Describe the aromas produced from aroma precursors during fermentation.
Describe the four quadrants of Vicente Ferreira’s Model for Wine Aromas.
Describe the contributions of phenolics to a final wine.
Describe the main techniques used in reductive wine making.
Describe the techniques a winery can implement to reduce their dependence on sulfur dioxide.
Describe the advantages of using cultured yeasts in the fermentation process.
Describe the changes that occur to wine that has undergone malolactic fermentation.
Describe the advantages of using oak alternatives.
Describe the fining agents that remove unstable colour and bitter phenolic compounds.
Describe a winemakers options for depth filtration.
Describe two stabilization methods for preventing refermentation in the bottle.
Describe how light strike can be avoided.
Describe the components that make up Total Package Oxygen.
Describe a one-plus-one closure.
Describe HACCP as an approach to quality assurance.
Describe the reasons a producer would choose to avoid skin contact in the vinification of their white wine.
Describe the advantages and disadvantages of using cane cutting as a method to dry grapes for making wines with residual sugar.
Describe the effect of noble rot on the style of the final wine.
Describe the options a winemaker has for blending in a sweetening component into a wine to create a style with noticeable amounts of residual sugar.
Describe the considerations a winemaker must make when choosing to use rack and return as a method of cap management during maceration.
Describe the purpose of a ganimede tank.
Describe the ideal characteristics of grapes that will be used to make a wine with carbonic maceration technique.
Describe the effect on aromas in red wine when warmer fermentation temperatures are used.
Describe the effect of oak maturation on mid priced to premium priced red wines.
Describe how lees aging will change the qualities of a red wine.
Describe what happens during early grape growth (pre-véraison). (10%)
Describe the vine characteristics a vineyard manager might consider when determining whether a grape variety will be suited to the growing environment of a new vineyard site. (15%)
- Time of budding – Early budding grape varieties, such as Chardonnay, are more at risk from spring frost damage compared to late budding varieties, such as Riesling.
- Duration of annual life-cycle – Early ripening grape varieties, such as Chardonnay and Pinot Noir, are best suited to cool climates, ensuring that they reach a suitable level
of ripeness before wet, cold weather starts towards late autumn. Late ripening grape varieties, such as Mourvèdre, are better suited to warm and hot climates. Early ripening
varieties in these climates would gain sugar and lose acidity too rapidly, resulting in unbalanced wines. - Tolerance of drought – Grape varieties that are able to withstand a high level of water stress, such as Grenache, can be the best option in dry climates such as the southern
Rhône, inland Spain and McLaren Vale. - Resistance to disease – Some grape varieties are less susceptible to fungal diseases, meaning that they require less monitoring and/or treating in damp climates. For example, Cabernet Sauvignon is less susceptible to grey rot than Merlot, one of the reasons why these two grape varieties make useful blending partners, particularly in maritime Bordeaux.
- Winter hardiness – Some grape varieties, such as Vidal and Riesling, are relatively tolerant of very cold winter temperatures, making them suitable for the harsh winters
experienced in Ontario and the Finger Lakes. - Vigour – If high vigour grape varieties, such as Sauvignon Blanc, are grown on fertile soils with plentiful water, it is likely that their vigour will need managing to avoid excessive
shoot growth.
Describe the use of the following substances in the winery:
a) metatartaric acid
b) bentonite
c) calcium carbonate
d) diatomaceous earth
(20%)
a) metatartaric acid
Adding metatartaric acid prevents the growth of potassium bitartrate and calcium tartrate crystals, reducing the need for cold stabilisation. However, the compound is unstable, and its positive effect lost over time, especially when wine is stored at high temperatures (25-30℃/77-86℉), meaning it is best used for wines designed for early consumption. It is a quick and easy process that tends to be used more for red wines as for white wines CMC is more effective and long lasting.
b) bentonite
Bentonite is a form of clay that absorbs unstable proteins and unstable colloidal colouring matter. It has a minimal effect on the flavour and texture of wine. It does lead to some colour loss in red wines and produces large amounts of sediment, and so wine is lost when it is racked off. Bentonite can be used to dine must as well as wine.
c) calcium carbonate
In cool climates where grapes may have to be picked before they are fully ripe (e.g. due to the threat of poor weather), it may be necessary to deacidify the must or wine. Deacidification is carried out by adding calcium carbonate, also known as chalk or limestone, and it lowers acidity by the formation and precipitation of tartrates.
d) diatomaceous earth
The most common form of depth filtration uses diatomaceous earth (“DE”, also known as Kieselguhr), which, once it has been processed, is pure silica and inert. The DE is wetted and used as a filter medium. Wine is sucked by vacuum from the outside of a rotary drum, through the DE, to the inside of the drum.
Describe what Eutypa Dieback is and ways to avoid it （15%）.
Describe the components contained in the pulp, skin and seeds of a wine grape (10%).
