wine making
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Week4_WineMakingPartONEppt_IntroductionofwinemakingandwhitewinemakingD2L.pptx
Week 4 Wine making Part ONE: - Overall Wine Making process
- White Wine
HB 409: Introduction to Wine
Hello everyone!
During Week 4, we will focus on wine making.
Part ONE online lectures begins with overall wine making process and then move to specific process involved with making white wine.
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Recap from Global History of Wine
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Wine making
(Growing grapes) and Harvesting
De-stemming and Crushing/Pressing
Fermentation
Clarification
Aging
Bottling and Sealing
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Wine making
Winemaking Part ONE (Week 4)
focuses on:
Harvesting
De-stemming and Crushing
Pressing
Part of fermentation
Part of clarification / aging
White wine production
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Week 4 Part ONE – Module A
Overview – Introduction to winemaking
The first step of winemaking: Harvest
“Veraison”
Aroma, Sugar, and Acidity
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Video Resources: An Introduction to WineMaking
(Source: Guildsomm, 2019)
https://www.youtube.com/watch?v=2PIvfUvlBvg
(14 mins)
Type and Style
Steps in wine making differ according to style, traditions, and the desired final products
The right combination of grape variety and climate
Germany and France: most part cool-climate wines
Many US wines: warmer climates
Great wine takes place in the vineyard:
Winemakers and viticulturists work together!
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The Grapes
Most desired for premium white wine
Chardonnay
Gewürztraminer
Riesling
White Riesling
Johannisberg Riesling
Sauvignon Blanc
Sémillon
Less commonly used for premium wine
Chenin Blanc
French Colombard
Grey Riesling
Welschriesling
Italian Riesling
Sylvaner
For premium wines, a cooler climate is normally preferred
Premium wines can be produced in warm climates
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https://youtu.be/ldm3pUFtLmE
(Source: Wine Enthusiast)
Video Resource: Different Climates – Different Tastes of Chardonnay
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Recap from Viticulture
Location of the vineyard will determine much
Climate
Soil depth, soil texture/composition, topography (physical feature of an area)
Integral Part of wine grape growing?
All of these relatively “fixed factors” influence
The color, sugar, acidity, aroma and flavor compounds in the grapes
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Harvesting
Pick quickly at optimal ripeness
- Decision for When to Pick?
Hand-picking
(Grapes are picked in the cool mornings or at night in warm regions)
Mechanical harvesting in many larger operations
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Optimal ripeness and balance between sugar and acidity levels
Harvest
are important factors to check.
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Grape Ripening: color change
Red grapes: from green to red
- beginning to sweeten
White grapes: the clusters turn from bright green to a more mellow golden green.
(called Veraison* in French)
Sweetness
Aroma
Size of grape
Chlorophyll (green)
Acid concentration
acid strength
As grapes grow and ripen
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Video resource: Veraison (40 seconds)
https://www.youtube.com/watch?v=w1r_mp1HC7I
(Source: California Wines by Wine Institute)
(Source: Grape Ripening by Wine Folly)
Grape Ripening: Aroma and Sugar
Aroma compounds increase
a correlation between aroma compounds and the degree of sugar
Sugars increase
The important sugars in grapes are
Fructose
Glucose
As sugar increases, varietal aroma increases and tartness (e.g., tannin level) decreases
Veraison
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Measure the sugar levels
Sugar levels monitored by winemakers and viticulturists
Sugar content is measured in terms of density in the grapes: Brix
Brix: Percent sugar content by weight
The desired amount of sugar in the grapes at the time of harvest depends on the wine being made
Tools: Refractometers, hydrometers
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Video Resource: How to Use a Hydrometer for Winemaking
(Source: OldManStino)
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Grape Ripening: Acid Content and Acid Strength
The lower the pH, the stronger the acid
pH of unripe grapes: 2.5-2.8
pH at time of harvest: 3.4-3.8
Higher acid strengths lead to
Brighter color of wine
Spoilage resistance
Sweetness decreases the sensation of acidity!
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White grapes are harvested earlier than red grapes.
Grapes delivered quickly and cooled upon arrival at winery
To avoid oxidation
More critical for white wine production
Please continue Part ONE- module B
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Week 4 Wine Making Part ONE: Wine Making Process and White Wine
Module B:
De-stemming and Crushing / Pressing
Free-run juice
Whole-cluster” pressed juice
Part of fermentation
Malolactic Fermentation
Part of clarification / aging
White Wine Making
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De-stemming and Crushing /Pressing
Week 4 Part A
Module B
Processing fruit begins at the winery with crushing and de-stemming.
Typically the grapes are crushed and pressed
For some wines, the crushed grapes sit a while before pressing
(Wine Cellar Insider)
(Wine Folly)
Crushing Grapes
Ideally, crushing simply breaks the skin gently, and let the juice flow, without damaging seed, stems and skins
Potentially high levels of tannin are found in the seeds, stems and skins!
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Crushing
Sulphur dioxide is often added at this stage
Wine preservation, prevention of further fermentation and other steps
Attempts are being made to decrease or eliminate the addition of Sulphur dioxide
Maximum legal limit for sulfites in wine for most countries: 335 to 350 ppm (U.S.)
Most finished wines between 20 and 50 ppm.
Up to 10 ppm are produced naturally during fermentation
If at 10ppm or higher must be labeled as containing sulfites
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Prior to Pressing
If the must is warm/hot, it may be mechanically cooled
Must: the juice being subjected to fermentation in the winery
Skin contact provides
Concentrated varietal aromas
Increased flavor compounds
May add tannins
Prior to pressing the must is often sent to a juice separator
Free-run juice
Has more sugar and less acid and tannin than press-run juice
Is finer and cleaner than in press-run juice.
(Wine Folly)
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Pressing the Grapes
After skin contact, or directly from crushing, and removal of free-run juice, the must is sent to the press
Increased pressure is applied as juice is extracted
The initial fractions are sometimes also referred to as free-run juice: Quality decreases as pressure increases.
In the making of white wine, the grapes are pressed immediately after crushing and possible de-stemming.
Each ton of grapes yields on average: 150-170 gallons
50-170 gallons of free-run juice
10-120 gallons of press juice
The traditional method of pressing grapes (basket – wood- press) is still commonly used.
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Pressing the Grapes
The left-over is known as pomace or marc
Often returned to the vineyard; can be distilled
“Whole-cluster” pressed juice
Making white wine product where the fruit is not destemmed.
Excess pressure can extract excess tannins from seeds.
- Discontinue pressure application after juice flow slows.
Many winemakers will clarify juice (e.g., white wine) by using clay-based products or letting juice rest and settle.
To retain a fruity character
In cool regions like Michigan, many winemakers
chill fruit juice for 12 to 48 hours after crushing and de-stemming
add sulfur dioxide to stop fermentation and oxidation.
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Fermentation
Fermentation
The juice is turned into wine through alcoholic fermentation
We need yeast and glucose
The yeast converts the glucose into
Ethyl Alcohol
Carbon dioxide
Heat
(Wine Folly)
Fermentation begins naturally within 6-12 hours when aided with yeast in the air.
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White wine’s fermentation begins soon after the initial crushing/de-stemming and pressing process.
(source: Wine Folly)
Fermentation
Wild yeasts are on the grape skins and in the local environment
Controlled by the addition of Sulphur dioxide at crushing
Wild yeasts can be used, but are often not preferred
Off-odors
Stop fermenting at 6-9% alcohol
Convert juice to vinegar and other unwanted products.
The fermentation process with wild yeasts may not progress in a consistent or timely manner (stuck fermentation).
Stuck fermentation: If the yeast is prematurely killed through heat and missing a needed nutrition, the fermentation may stop prematurely.
Most wineries use commercially prepared and available yeast.
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Fermentation
Monitoring sugar level by a hydrometer
Chaptalization: Addition of sugar at the start of fermentation (or unfermented grape) to increase the alcohol content after fermentation.
Adjusting the acidity
Controlling the heat
The cooler the fermentation the higher the quality of wine
50-60ºF is normal for white wine
High temperatures lead to a loss of desired flavors and aromas
Winemakers constantly monitor must temperature.
White wine is often fermented at cooler temperatures
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Fermentation
Fully fermented
Allowing the fermentation to proceed to its natural end
All glucose has been converted
Some unfermented residual sugars may remain: 0.2-0.3%
Stopping fermentation by deep-chilling and removal of inactivated yeast
Residual sugars are higher
Some add “sweet reserve” instead
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Fermentation
Malolactic fermentation
Often used for Chardonnay
Adds buttery notes and complexity
Makes the wine softer and more accessible
Converts malic acid to lactic acid and carbon dioxide
Often reduces
Varietal characteristics
Fruit flavors
May introduce non-desirable flavors
Malolactic fermentation (MLF): converting tart malic acid into soft lactic acid and carbon dioxide.
MLF used for both white and red wines!
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Video Resource: Malolactic Fermentation (3 mins)
(Source: GuildSomm)
After fermentation
Clarification: Process in which tannins, proteins, and dead yeast is removed from the wine.
Storage, Clarification filtration, aging, blending, stabilizing, adjusting wine chemistry and bottling.
- Check Winemaking Part II lecture file!
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Clarifying
The wine will be clarifying naturally if left alone, but winemakers are impatient and help it along
Racking
Filtering
Fining
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Aging
Wine increases in complexity and darkens somewhat
The various components in the wine interact with one another to develop bouquet
Most white wines do not benefit from long aging periods.
White wine that are most likely to benefit from some aging, come from cooler growing regions.
Flavor elements may be added
Oak? Mostly Chardonnays, but also Fumé Blancs and Chenin Blancs, and a few Rieslings
The typical intent is to preserve the fruit and youthful characteristics of the white wine
Short aging in stainless steel tanks
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Aging in Oak
Loss of alcohol and water through the wood
Concentrating the wine
Oxygen is slowly dissolved in the wine
Allowing some oxygen dependent maturation
Substances from the oak are dissolved into the wine
Color, flavor, tannin
Oak preferred over other woods due to tight grain, strength and resilience and ability to be shaped into barrels
Different oaks respond differently
Slow growing oaks are preferred
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Week 4 Wine Making Part ONE: Wine Making Process and White Wine
Module C:
Case Example: One of the Biggest Wine Cellars in the World: Milestii Mici Winery (Moldova)
Sur lie aging
Blending and Finishing
How Chardonnay is made (Napa Valley Vintners)
White Winemaking of Burgundy (France)**
One of discussion forum questions
White Wine Making
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Video Resource: One of Biggest Wine Cellars in the World: Milestii Mici Winery (Moldova)
(Source: Davidsbeenhere)
Sur Lie aging
To rack or not to rack?
Sediment (e.g., leftover yeast and grape particles) in the fermentation tanks are called lees
Sur lie aging
Some wines are left on the lees during aging
Adds complexity to the finished wine
A creamy flavor
Must be monitored as non-desirable flavors can develop
(Wine Folly)
Lees are used in white wines to add beneficial textures and flavors.
(Winemaker’s academy)
Video Resource: Sur Lie Aging example (see inside a wine barrel) – 1 min
https://www.youtube.com/watch?v=g-7bTxrX0dY
(Source: Jordan Vineyard)
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Blending and Finishing
Blending is often done to achieve a desired end result
Blends:
Between varietals
Within a varietal
Different vintages, batches, treatments
Labeling laws and conventions
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Video Resource: How Chardonnay is Made (Napa Valley Vintners) - 2 mins
(Source: Napa Valley Vintners)
https://www.youtube.com/watch?v=0x2Uo2h6jco
Video Resources: White winemaking in Burgundy
(Source: Liquor Control Board of Ontario)
https://www.youtube.com/watch?v=dyc8fvpOOl4
Please watch one of the video clips for responding to one of questions (week 4 discussion forum)
(Source: Elicite)
https://www.youtube.com/watch?v=Z_fIt80pMG8&list=RDCMUCaxdsXEk1V37Q3Q6HFwB0pA&start_radio=1&t=27
19 mins
7 mins
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HB 409: Introduction to Wine
Next! Week 4 Winemaking Part II Online Lecture – Making Red Wine
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