2.5 Winemaking Flashcards
What is crushing?
Splitting the grape skins to release the juices
What is pressing?
Squeezing the crushed grapes in a press to extract the liquid. Can be either pre or post fermentation.
What is alcoholic fermentation?
Yeast feeds on the sugar in the grape must. Sugar carbon dioxide and heat are produced.
Generally, yeast will consume all the sugar resulting in a dry wine.
What is abv?
Alcohol by volume (expressed as a %)
Most wine is between 11.5% and 16% abv
What is storage/maturation?
Post fermentation, new wine is stored for some time before bottling
a few months-1 year (most wines) flavors change little
Extended storage (more than 1 year) is less common, but wines begin to develop tertiary flavors/aromas and tannins integrate. Often in oak (adds secondary flavors/aromas)
Name some packaging options?
Glass bottles
Bag - in- box
Plastic bottles
Bricks (i.e; Tetra Pak)
List the steps, in order, for red winemaking
Crushing
Alcoholic fermentation
Draining
Pressing
Storage/maturation
Packaging
What color grapes are used to red wine?
Black
The skins must be included in the fermentation so that the grape must can extract color and tannins.
What happens in red winemaking immediately after fermentation? How/why?
Draining
To separate the new wine from the skins, dead yeast cells and other solids (the “lees”). The largest particles, separated through the initial draining process (“racking”) are called the gross lees. Failure to remove the gross lees can lead to bacterial spoilage.
How are color and tannin extracted durng fermentation?
The heat created by fermentation helps to extract color and tannin. But CAP MANAGEMENT is the process of helping the skins to remain submerged.
Usually either Punch down
OR
Pump over
What is Punch down?
A plunger’s used to manually push the solid down into the liquid (carefully, so as to not squish the seeds)
What is Pump over?
Using a pump to move grape must from the bottem of the fermentation vessel over the top of the cap.
How does Rose’ winemaking differ from red winemaking?
2 common methods
- Short maceration (skins are left in contact with the juice for several hours, then removed) and fermentation continues
- Blending (add a bit of red wine and mix with white wine)
List the steps of white winemaking?
Crushing
Pressing
Alcoholic fermentation
Storage/maturation
Packaging
Notice pressing occurs before fermentation
What color grapes are use to make white wine?
Usually white…. but you can also use black grapes to make white wine!
What’s the name for sugar remaining in the wine after fermentation is complete?
Residual sugar
List the techniques that can be used to make sweet wines?
Concentrated grape sugars
Removing the yeast
Killing the yeast
Adding sweetness to the wine
What methods are used to concentrate grape sugars?
Late harvest/extra-ripe grapes
Botrytis
Frozen grapes
Grapes that are dried after harvest
Why is it possible to make sweet wines from grapes with concentrated sugars?
The yeast generally can’t eat all the sugar
ex: Tokaji Aszu
How are yeasts removed prior to the completion of fermentation in order to make sweet wines?
with filters
ex: White Zinfandel
What method is used to kill the yeast in order to produce a sweet wine?
Fortification (add alcohol)
ex: Port
What sweetening agents are sometimes added to wine to increase sweetness after fermentation?
- Unfermented grape juice
- Sugars in grape juice can be concentrated into an extremely sweet liquid
- Sweet wine can be blended with dry wine.
What categories of tools are in the winemaker’s toolbox to influence wine style? (8)
Adjustments
Fermentation Temperature
Winery vessels
Oak alternatives
Malolactic conversion
Lees
Blending
Clarification
When might a winemaking choose to adjust the must?
When the grapes don’t have the right proportion of acid or sugar
The goal is to improve the BALANCE of the wine
How and why are sugar adjustments made?
If sugar levels are too low (cool climate or an unusually cool vintage), the wine will have low alcohol and vey light body. To improve this, sugar can be added prior to fermentation.
How and why are acid adjustments made?
- Warm climates (low acid) - acid can be added
- Cool climates (high acid) - the acid is neutralized by the addition of a compound such as calcium carbonate.
True or false: Alcoholic fermentation generates heat. The temperature can impact the style of wine that will be produced as should be monitored.
True
What temperature issues/concerns are common in red wine production? What are common fermentation temperatures?
Reds are usually fermented at higher temperatures to aid in the process of extraction.
68-90 degrees F
What temperature issues/concerns are common in white and rose’ wine production? What are common fermentation temperatures?
Temperatures are cooler than for red wines - it’s necessary to protect the more delicate aromas and flavors.
54-72 degrees F
What types of winery vessels are used for fermentation and/or storage/maturation?
Stainless steel
Concrete
Oak
Which types of vessels are inert (neutral)?
Stainless steel
Concrete
What are stainless steel and concrete vessels used for?
Either fermentation or storage
Why are stainless steel and concrete inert (neutral)
the composition does not impart flavor to the wine
They’re airtight - preventing exposure to oxygen (oxidation)
What wood is most commonly used for winery vessels?
Oak
(Chestnut and other woods are sometimes used in certain regions)
Why would a winemaker choose to use an oak vessel?
- Oak adds flavors such as coffee, vanilla and smoke
- Oak allows development of tertiary aromas/flavors through slow oxygen exposure
What factors impact the degree of flavor an oak barrel imparts to wine?
- How the barrel was produced
- Barrel age
- Barrel size
- Type of oak
How are oak barrels made?
Oak staves (planks) are heated around an open flame and bent into shape. The level of “toast” impacts the flavor characteristics that are imparted to the wine ( sweet spice and charred wood aromas/flavors).
Metal hoops are placed around the staves to hold the barrel in place.
How does barrel age impact the flavors/aromas imparted to wine?
New barrels add a great deal of flavor.
Previously used barrels impart less flavor.
After 2-3 uses, barrels impart little flavor.
After many uses, barrels are called “old oak”
What flavors can oak impart to wine?
Vanilla
Coconut
Charred wood
Spice
Are oak barrels watertight? airtight?
Watertight - yes
airtight - no. Oxygen SLOWLY moves in and out of the barrel pores - adding flavors such as caramel, dried fruit, hazelnut, almond and walnut)
Oxygen also helps to soften tannins
Do small or large barrels impact the flavor of wine more?
Small barrels
More wine is in contact with the surface area of the barrel.
What are oak alternatives used for in winemaking?
The impart some oak flavor and are MUCH cheaper than barrels.
Oak staves, oak chips etc.
What is Malolactic conversion used for in winemaking?
It changes tart malic acid into softer lactic acid.
it lowers total acidity and creates buttery flavors.
Is Malolactic conversion used in all wines?
It;’s used in almost all red wines. (buttery flavors aren’t discernable)
For whites, it is a stylistic choice. It’s common with Chardonnay. I’s rare with aromatic white grapes.
What are Lees?
Dead yeast cells
Why might a winemaker choose to leave a wine in contact with the FINE lees during maturation?
Especially if stirred, the lees impart additional flavor and texture, increasing complexity and mouthfeel.
Biscuit, bread
What’s blending and why is it used?
It defines and maintains style - enabling a winemaker to create a house style that’s recognizable year after year.
Complexity
What’s clarification?
Used to create perfectly clear wine
Filtration
Use of egg whites or diatomaceous earth, which bond to microscopic solids, allowing them to be removed
a downside of filtration is that it can strip flavor, as well as solids.
Do all wines have the potential to improve in bottle with age?
No
~5 % of whites
~10% of reds
What happens to NON age-worthy wines as they age?
The fruit flavors fade and are replaced with vegetal notes.
What components in wine increase the potential to improve with age?
High acidity
High levels of tannin
High levels of residual sugar
Concentration of flavors that have potential to evolve positively
Balance
How can fruit flavors develop with bottle aging?
Fresh fruit evolves into dried fruit
Flavors such as mushroom and leather develop
How do white wines change with age?
Color - deepens from lemon to gold to amber
Tertiary flavors such as dried apricot, spice, honey and nut develop
How do red wines change with age?
Color - changes from ruby to garnet to towny to brown and grows lighter
Tannin become softer
Tertiary flavors such as fig, prune, meat and wet leaves develop
Sediments develop
