What grape variety would be most consistently used for premium wines rather than jug wines?
Weather refers to the generally prevailing weather conditions in a region such as temperature, wind speed, rainfall, etc. averaged over a series of years.
False, the definition is for climate.
The climate of a vineyard is called a _______.
The degree to which a grapevine's foliage and fruit are exposed to light can determine the amount of distinctive flavor compounds in its grapes.
If the amounts of the chemicals responsible for the celery/fresh vegetable, herbaceous, or grassy character of Sauvignon Blanc are reduced, fruity flavors of grapefruit, pineapple, melon and fig will emerge.
According to the grape growers surveyed, which vineyard factor does not promote grassiness in Sauvignon Blanc?
When grapes ripen, they get bigger and softer, their green color fades, aromatic compounds increase, sugars increase, and both total acid concentration and acid strength increase.
False, both total acid concentration and acid strength decrease.
For winemaking, the most important sugar in grape juice is sucrose.
False, the most important sugars in grape juice are glucose and fructose.
The amount of sugar in grape juice is estimated by measuring its density in units called "degrees Brix", which correspond to the percentage by weight of sugar in the juice.
If you were buying Chardonnay grapes for your winery, what composition would you like them to have?
22.9 degrees Brix, 0.80 total acid
Why can grapes from 2 vineyards with the same hot daytime temperatures have different acid compositions?
On cool nights, the grapes need less energy and use up less malic acid. Locations with cooler nighttime temps produce fruit that is higher in malic acid than produced in sites where it stays warm all night.
The weakening of acid strength during ripening is more important for wine quality than is the decrease in the total amount of acid, because wines with stronger acid strengths have brighter colors, require smaller amounts of sulfur dioxide to protect them, and more easily resist spoilage.
Refractometers are used to estimate the degress Brix of properly collected vineyard sample and can also be used to measure the disappearance of sugars during fermentation.
False, hydrometers can do both of these measurements.
This winemaking step ideally involves only breaking the skins of the grape berries to allow the juice to flow out without any damage to the seeds or stems.
The mixture of skins, seeds, stems, juice and pulp produced when the skin of the grape is broken and the juice flows out is called _____.
Sulfur dioxide is added at the crusher to slow down the growth of microbes that can spoil wines and to protect the juice from reactions with oxygen that can lead to both browning of pigments and deterioration of aroma and flavor.
A typical sulfur dioxide in wine would be _____?
35-125 parts per million
Sulfur dioxide is only added once during winemaking, at the crusher-stemmer.
False, sulfur dioxide levels are monitored throughout winemaking, and small amounts are added whenever they are needed.
For premium white varietal wine production, skin contact means that the chilled must is pumped into a tank to sit for several hours.
Free-run juice has more sugar and less acid and tannin than press-run juice because press juice is extracted at higher pressures from must containing a higher proportion of stems, skins and seeds.
Grappa can be produced when press juice is fermented and then distilled.
Modern premium winemaking equipment allows the extraction of about 135-185 gallons of juice per ton of grapes. This is made up of 3X as much press run juice than free run juice.
False, its about 3X more free run than press run.
The grape solids in the must are called pomace.
A juice with about 20 degrees Brix will yield a wine with about 10% alcohol through fermentation by yeasts, primarily from the genus Saccharomyces.
Because carbon dioxide gas is produced during fermentation, fermentation tanks are equipped with one way valves that allow CO2 to escape while preventing air from entering.
Wild yeasts are not used by most wineries because they can produce off odors and typically will stop fermenting around 6-9% alcohol.
Why does the degrees Brix not drop much during the early stages of white wine fermentation?
Because while the yeast cells are metabolizing with the aid of the dissolved O2 in the grape juice and increasing in number, they have not consumed enough glucose to change the density of the juice.
What additional evidence of yeast growth and metabolism, besides the drop degrees Brix, do wineries measure during the active stage of fermentation?
Another indication of the increased fermentation activity of the yeasts is the warming of the fermenting juice.
A stuck fermentation is one that cannot be stated
False, its one that stops by itself before all the glucose has been used up.
What procedure would you not expect to be done before fermentation of Chardonnay?
A probably fermentation temperature for premium quality white table wines would be about?
55 degress F
Wines of 2-3% of residual sugar can be made by slowing down their fermentations before all the sugar has been used up by chilling them at about 4-8 degrees Brix and then centrifuging to remove the cold-inactivated yeast.
Sediments in wine tanks are called lees.
You are having dinner at a friend's house and drinking a delicious bottle of white wine. The label says "Callaway Vineyard and Winery 1990 Calla-lees Chardonnay in the Classic Sur Lie Style" What does "sur lie style" mean?
In some cases, most commonly for Chardonnay, the winemaker may want to add a yeast character similar to champagne bouquet to the wine and will allow the wine to remain in contact with the yeast for weeks or months.
The malolactic fermentation reduces the acidity in the fermenting grape juice and finished wine because it converts the malic acid from the grape juice to lactic acid, which is less tart.
What additional changes occur in wines that undergo the malolactic fermentation?
In addition to reducing acidity, the MLF causes other organoleptic changes. If produces gas and causes the wine to be less fruity and to have transient cheesy off odors, but it also allows them to develop greater complexity, including a buttery flavor, with aging.
The malolactic fermentation is most often used to reduce the acidity of warm region or warm to hot season grape juices.
It is critical for winemakers to control the timing of the MLF to be sure that it is completed before bottling.
Because most of the worlds white table wines emphasize the aroma of the grapes and the MLF reduces fruitiness, most winemakers take precautions to prevent the MLF altogether in these wines.
The process of transferring wine from one vat containing less to another vat which is clean is called ______.
If wine can be made perfectly clear simply with settling and racking, why do few wineries rely on these methods?
Wineries do not use these slower, "natural" methods because the wine would be too old for contemporary tastes by the time it reaches the market.
In filtering, the wine is forced through media that vary in "tightness" from those that trap and remove just the very largest particles (chunks of grape skins) to those that take out tiny malolactic bacteria.
Fining is a clarification process that is used to alter other important organoleptic properties of wines in order to clarify them.
Fining agents such as gelatin and egg albumin react with the specific wine components (tannin) that are to be removed and form particles that can be removed.
A wine is neither heat- nor cold-stable if it becomes cloudy when exposed to high temperatures, and it forms crystals when subjected to temperatures around 32 degrees.
Making sure wines are microbiologically stable is designed to prevent gassiness and the development of off odors and flavors from bacteria and yeast growth during barrel aging.
False, microbiological prevents cloudiness.
Sterile filtration followed by aseptic bottling are key strategies in creating microbiogical stability.
Because vinegar bacteria can spoil wine only in the presence of O2, winemakers minimize air contact with wines in bulk storage.
Because nearly all white table wines are valued principally for their youthful, fruit characteristics, the vast majority of white wines are aged in neutral containers only for as long as it takes to clarify and stabilize them. Only a tiny minority of the world's white wines are candidates for aging in oak containers.
What 3 things happen when wines age in oak barrels?
Alcohol and water evaporate through the sides of the containers, concentrating the wine. Some O2 dissolves in the wine, allowing O2-dependent maturation reactions to occur slowly. Substances such as color, odor, and flavor components and tannins from the wood are extracted into the wine.
Why has oak become the traditional aging container for wines?
Trees are large enough to make wine containers in useful sizes, wood is tight grained, strong, make curved shapes, and flavors are extracted.
American oak barrels will import more oak or vanilla flavor to wines than will European oak barrels.
For winemaking, oak from the forests of France is all pretty much the same.
Larger barrels will import more oak character to wines than smaller barrels.
Under what aging conditions will the components of the wine in a barrel become concentrated?
The barrels are stored in a relatively dry environment such as an above ground warehouse in California.
Describe the aging regime you would use for White Riesling or other wines to which you want to add very little or no oak flavor.
Such wines are either aged in stainless steel tanks or large, typically oval shaped oak barrels of 500-2000 gallons capacity.
You are going to make your mark in the wine world by creating a rare style of dry Chenin Blanc with a lot of oak character. What aging regime would you use?
You could begin by fermenting Chenin Blanc juice in oak barrels and add more oak by aging the wine for several months in the new 60 gallon American oak barrels.
Many California wineries have found that oak chips or oak structures added to wines in stainless steel tanks can satisfactorily duplicate all aspects of the barrel aging process and are much cheaper.
There are certain conventions based on flavor and structural compatibility that are followed by many producers when making varietal blends. For example, Chardonnay and Chenin Blanc are often blended.
False, Chardonnay and Pinot Blanc are more often blended.
The bottle shape and color are chosen for a particular wine based on the traditional shapes and colors used in the European wine. Clear Bordeaux bottles are often used for Sauvignon Blanc and Sermillon varietal wines.
Corks come from the bark of an oak, Quercussuber.
The date that bottles in the case were filled is stamped on the box. This is useful for estimating the approximate drinkability of wines without vintage dates.
You have been hired by Chateau Prestigious Wine Cellars to protect their cash flows in the 1st year of operation. Based on your extensive knowledge of the white wine making process, you could calculate that the 1st income for the sale of their oak aged Chardonnay wines would come at about how many months after the harvest?
You lost your job when Chateau Prestigious Wine Cellars folded because its 1st year cash flows were gobbled up by the owners high living son in law. Luckily you have been hired by the neighboring wine cellar, Chateau Very Ordinary, and asked to project their cash flows. Based on your extensive knowledge of the white wine making process you calculate that they could expect to first earn income from the sale of their Jus' Plan Mountain Chablis wines about how many months after the harvest?
Blends are typically made the same day as the wines are bottled
California coastal wineries store bottled wines an average of 4 months at the winery until they are released for sale.
What is not a part of "the best possible aging conditions" for bottled wines?
The best wines will improve indefinitely after bottling is kept under the proper conditions
False, only will improve to a certain point.
What wine is the worst for bottle aging?
For premium white varietal grapes grown in California, cooler growing regions produce wines with greater aging potential.
What changes would you expect when white wines age in the bottle?
Increased complexity and moderated tartness
California wineries use sensory evaluation in quality control, and the average tasting situation involves 5 tasters examining no more than 10-30 wines per day.
False, it involves 5 tasters who examine 30 wines per day in 1-3 sessions
Which components of white table wines 1. Originate from grapes, 2. Are fermentation end products, 3. Are developed during aging?
1. color, sugar, acidity, varietal aroma, and flavor.
2. alcohol and carbon dioxide
3. malolactic fermentation and/or oak barrell and/or sur lie aging flavors
What winemaking steps would you use to make a Sauvignon Blanc without grassiness?
Harvest at 22 degrees Brix or above, no skin contact, ferment in barrels and at warmer temps, age in oak sur lie, and blend with Sermillon or Chardonnay
In 1990 white table wines, roses, and blush varietals constituted 53% of the shipments from California wineries to domestic markets.