Natural and Human Factors in the Winery that can influence style, quality and price of a wine. Flashcards
Name the five parts of a grape?
Seeds and Stems, Bloom, Pulp, Tannins and skins
What do the seeds and stems contribute to the wine?
Tannins
What is the bloom?
Waxy surface that covers the skins of the grape and contains the native yeast that can be used to ferment the wine.
What does the pulp of the grape contain?
Water, sugar, and acids (tartric acid and malic acid)
What is a tannin?
Chemical compound that tastes very bitter, which falls as the grapes ripen
What does the grape’s skin contain?
High concentration of flavour compounds, also tannin and colour compounds
Why do winemakers use counteractive measures against oxygen during winemaking?
To preserve the primary fruit characteristics.
What are some examples of anaerobic or protective wnemaking? (keeping oxygen at minimum)
using sulphur dioxide, picking grapes at night when cooler, keeping grapes chilled until they reach the winery, filling winery equipment with carbon dioxide or nitrogen
Do wines that have been protected from oxygen during winemaking benefit from oxygen during maturation?
No
What affect does maturing wine in oak have?
Exposed wine to small amounts of oxygen, softens the tannins, creates more complex secondary and tertiary flavors to develop.
Do smaller barriques have greater oxidative effect than larger vessels?
yes
Do wines matured in barrel longer than two years generally go in smaller vessels or larger vessels?
Larger, to prevent too much oxidation.
Why is Sulphur Dioxide used in winemaking?
Acts as antioxidant and an antiseptic
What affect can oak tannins have on a wine?
gives more structure to both red and white wines, increases textural complexity
What are the four factors to consider when choosing which oak to use?
Species and Origin of oak, size, the production of the barrels (such as toasting), age, oak alternatives (staves or chips)
At what age does an oak barrel become neutral?
Fourth usage
When do grapes usually receive their first does of SO2
When they first arrive at the winery
What is free run juice?
When the grapes are crushed upon arrival it produces an initial juice
Are destemming and crushing done for all grapes on reception?
No, machine harvested grapes are already de-stemmed
What is the process that separates the liquid and the solid constituents of the grape?
Pressing
Why is it important to be gentle in both crushing and pressing?
So as not to crush or break the seeds which release unwanted bitter flavours
When do you press for white wines and when for red wines?
White wines are pressed prior to fermentation and reds are pressed after fermentation.
During winemaking, grape juice can also be referred to as xyz?
Must
What are three adjustments that can be made in the winery to improve a wine?
Sugar, alcohol and acid
What is enrichment?
Adding sugar to wine in the form of rectified concentrated grape must (RCGM)
What is chaptalisation?
adding sugar from other sources such as sugar beet
How do you remove alcohol from a wine?
Modern machinery can remove alcohol after fermentation is complete
What is acidification?
The addition of tartaric acid in powder form. Used in warm and hot regions
Deacidification is what?
Removing acid usually in cooler climate regions
What is fermentation?
The conversion of sugar into alcohol and CO2 through the action of yeast
Alchoholic fermentation will not begin until the temp is above what?
5 degrees celcius
Alcoholic fermentation will stop before all the sugar is consumed in two circumstances, what are they?
The yeast runs out of the nutrients it needs or the temperature rises above 35 degrees celcius
If the winemaker wants to stop fermentation, how do they do so?
By killing or removing the yeast (adding sulphur or grape spirit to kill or filtration to remove)
If a winemaker wants to remove the yeast, what steps do they take?
They stop fermentation by chilling the wine below 5 degrees celcius and then they filter out the yeast
What are the two important ways a winemaker can control the fermentation?
The choice of yeast and the control of temperature
What happens if fermenting wine gets too hot?
It can kill the yeast
What is the benefit of fermenting at low temperatures?
Winemaker can influence the flavors of the wine.
Fermenting at low temperatures aids in what flavours in white wine?
Retains fruit character in white wine and floral characters in white wine.
Why is fermenting at hot temperatures important for red wine?
Extraction of colours and tannins for red wine
What are ways a winemaker can control the temperature during fermentation?
Temperature controlled fermenting vat or pumping over also releases heat
What has been a huge contributing factor in the quality and consistency of modern wine?
Temperature control in fermentation
What affect does MLF in wines?
It softens and reduces acidity, creates buttery flavours
How does a winemaker encourage MLF?
raising the temperature of the wine and by not adding SO2 after alcoholic fermentation
How can a winemaker prevent MLF?
By storing wine at cool temperatures and adding SO2 or filtering out bacteria
What are gross lees?
Dead yeast cells
What happens if the lees is not removed?
It can cause unpleasant aromas to develop in the wine
What are fine lees?
The smaller particles that settle more slowly, they are removed more gradually
Why would a winemaker choose to keep white wine in contact with its lees for a period?
To add extra flavours and a richer texture to the wine
What are the six constituents of a wine?
Water, Ethanol, Sugars, Acids, Tannins and Colours, Aroma and Flavor Compounds
When does blending usually take place in winemaking?
Can take place at any time but usually after fermentation or during the maturation process.
What three things can blending help achieve?
Balance, consistency and style
What could a winemaker do to increase the tannins in the final product of a red wine?
Blend the free run wine with the press wine
What are the things during winemaking that can cause inconsistency?
small barrel wines mature differently individually, variations of fruit due to different vineyards or different harvesting times.
What are the three main techniques a winemaker uses to achieve clarification?
Sedimentation, fining and filtration
When do wines go through sedimentation?
After fermentation has finished
What is racking?
it is a process of sedimentation. Once the gross lees have settled in a deposit, the wine is slowly and gently pumped into a different vessel leaving the sediment behind
Why would a winemaker do repeated rackings?
The wine will continue to throw a deposit of fine lees during maturation, repeated rackings can improve clarity of wine
What is fining?
Adding a fining agent which is a substance that forms bond with wine constituents and causes clumps to form, then remove clumps by filtering. Fining speeds ups the natural haze or deposits that may appear in a bottle over time
Besides making a wine more clear, why else would you fine?
To improve the stability of the wine.
What is filtration?
Physically removing particles from wine as it passes through a filter. (gross and fine lees)
When do you filter a wine?
After fermentation and during maturation
What are the two methods of filtration?
depth filtration and surface filtration
Are fining and filtration used for all wines?
No, some winemakers believe that fining and filtration can affect a wine’s character and texture
When does a winemaker consider a wine stable?
It is stable if over a period of time the wine changes in a slow and predictable manner
Fining has two purposes, what are they?
To improve clarity and helps stabilize a wine
What are three important areas that require stabilization?
Tartrate Stability, microbiology stability and oxygen stability
What are tartrates?
Crystals in wine formed over time from the tartaric acid
What is the problem with tartrates?
Although harmless, most consumers do not like them in their wine
How does a winemaker get rid of tartrates?
They remove them using filtration
What causes a wine to microbiological instability?
Forms of yeast or bacteria can spoil a wine and make it undrinkable
Which wines are not at risk for microbiological instability?
Fortified wine (cannot survive in high alcohol)
Which wines are at most risk of microbiological instability?
Wines that have not undergone MLF, wines with low to medium alcohol and low acidity, and a little residual sugar
What happens when a wine oxidizes?
When excessive levels of oxygen dissolves in the wine, , loses fresh fruit aromas and gradually turns brown
How does a winemaker prevent oxidation?
SO2 or flushing bottles with nitrogen or carbon dioxide
What are the common elements in the winery?
Roles of Oxygen, Roles of SO2, winery vessels, alcoholic fermentation, malolactic fermentation
What are the three adjustments that can be made in a winery?
Must enrichment, acidification, deacidification
What is the process of white wine making?
Grape variety, grape reception, destemming, crushing, , skin contact, pressing, clarification, alcoholic fermentation, racking off gross lees, MLF
What is the process of red wine making?
Grape variety, grape reception, destemming, crushing, pre-fermentation extract, alcoholic fermentation and extraction, post-fermentation extraction, pressing, MLF, whole-bunch fermentation (carbonic maceration, semi-carbonic maceration, whole bunches with crushed fruit)
What is the process of rose winemaking?
direct pressing, short maceration, blending
What is the process of sweet winemaking?
interrupting the fermentation, adding a sweet component, concentrating grape sugars
What is the maturation process?
Oak vessels, inert vessels, lees contact, oak alternatives
What is the reason for blending?
Balance, consistency, style
What are the three types of clairification?
Sedimentation, fining, filtering (depth, surface)
What are the two elements of stabilization?
Tartrate and microbiological
What are the three types of packaging?
Glass, plastic, bag in box
What are the three types of closures?
Cork, synthetic cork and screwtop
