VINICULTURE–Fermentation

  • SUB-TOPICS Of VINICULTURE-FERMENTATION
    1. What is Fermentation?
    2. Yeast
    3. Sugar
    4. Oxidative
    5. Reductive
    6. Other Topics of Viniculture-Fermentation
      1. Fermentation vessels
      2. Carbonic Maceration

1) WHAT Is FERMENTATION?

FERMENTATION–  Enzymatic Conversion of Sugars Into Alcohol…Fermentation is the Conversion of Glucose and Fructose Into Ethanol With Carbon Dioxide, Heat and Substrates as by-Products.

  • Sugar In Grapes Are Converted By Enzymes In Yeast to 55% Ethanol, 40% Carbon Dioxide and Heat. Yeast Cell Takes One Sugar Molecule and Converts Into Two Ethyl Alcohol Molecules, Two Carbon Dioxide Molecules and Heat.  Fermentation Produces .55%- .59% Ethanol For Every Degree of Brix In Initial Must.
  • Fermentation is a Transformative Process. It Producers Alcohol But Also Producers Most of the Wine Aromas, Flavors and Texture.
  • Substrates- Nitrogen, Fatty Acids, Esters, Organic Acids, Sulfur and Sugar.
  • One Sugar Molecule= C6H12O6 +Yeast= 2 C2H5OH + 2 CO2 =Ethanol Molecules.
  • Fermentation Can Take a Week or Month or Year.
  • Fermentation is Guided by the Winemaker Generally Using Specific Yeast That Are Cultured, Monitored and Added as the Need Arises.  Depending On the Grape Varietal There Are a Few Different Options But Generally the Process is the Same.

“Grapes Are the Only Fruit With Enough Sugar to Ferment Into a Drink With Enough Alcohol By Volume to Preserve it.”

WINE– Term For Any Fermented Alcoholic Beverage That’s Produced From Grapes or Other Fruits.

“Every Step From Before Bud Burst to After Bottling, Wine Can Be Effected By Chemistry, Either to the Benefit or the Detriment of the Wine.”

WINE CHEMISTRY– Helps Explain the Relationship Between Flavors, Aroma Etc. In a Wine and How They Determine the Taste, Structure Etc. In the Finished Wine.

“Wine is a Complexed, Unstable Chemical Mixture of +350 Compounds Including…Sugars, Acids, Ethanol Alcohol and 200 Aromatic Esters. To Enjoy Wine One Doesn’t Need to Be a Chemist But a Fundamental Understanding of the Field is Needed to Understand Wine Better.”

ZYMOLOGY- Science and Study of Fermentation.

  • THINGS To MONITOR DURING FERMENTATION
    • Temperature   |   Yeast Health
    • Amount and Kinds of Nutrients
    • Brix Level   |   ABV. Level

FERMENTATION TEMPERATURE

COLD vs. WARM vs. HOT FERMENTATION

  • Fermentation Temperature Has Profound Effect On the Efficiency and Length of the Fermentation and the End Character of the Wine.
  • Fermentation Will Only Take Place Between a Temperature of 38°- 90°
  • TEMPERATURE FOR FERMENTATION
    • White= 50°- 68°  |   *Optimal- 52°- 60°
    • Red= 70°- 85°   |   *Optimal- 72° – 78°

COLD FERMENTATION

  • Cold Fermentation That Take More Time Will Preserver Most of the Volatile Aromas That the Yeast Produced From the Compounds of the Grape. Too Cold of a Fermentation and the Yeast Will Slow or Shut Down.
  • Fermentation of Juice at Cooler Temperatures Will Tend to Retain Delicate Flavors, Aromas and Varietal Characteristics. There’s a Balance Between Warm and Hot Fermentation and It’s Up to Wine Maker to Know What He Wants to Get Out of the Finished Wine.

HOT FERMENTATION

  • Hot Fermentation Will Produced a Lot of Ethanol and Not a Lot More. Too Hot and the Yeast Will Race to Completion Without Adding Nuance or Might Die Off.

“Hot Fermentation Can Lead to the Lose of Positive Qualities and the Addition of Unwanted Attributes.”

2) YEASTS– Living, Microscopic, Single Celled Micro-Organism (Enclosed by Membrane Wall), Also Called a Fungus

  • Yeast Used In Fermentation: Saccharomuces Cerevisiae is the Primary and Most Important Yeast But Candida Stellata, Hansenula, Kloeckera Apiculata, Metschnikovia and Pichia Membranaefaciens,  Are the Yeast That Kick-Starts Fermentation. These Yeast Works Until the Grape Must Reaches Around 5% ABV. Then Dies Off and Saccharomyces Cerevisiae Takes Over and Completes Fermentation.
  • Zymologist Have Identified Thousands of Yeast Strains With Specific Purposes.
  • Grapes Have All the Potential Aromas In Their Skins and It’s the Yeast That Processes the Compounds and Reveals the Aromas and Flavors That We Identify In Wine.
  • The Attribute of Varying Indigenous Yeast In Different Regions is Why a Chardonnay From California is Slightly Different Than a Chardonnay From Burgundy.
  • Bloom- Coating of Native Yeast and Marco-Organisms That Attach to a Grapes’ Skin.
  • Bloom On the Grape is Mother Natures’ Way of Sitting, Waiting to Get Into the Grape and Commence the Process of Breaking Down the Grape and Returning the Nutrients Back Into the Earth to Start the Process of Life Again.

“Outside of Grape and Terroir the Yeast Plays the Biggest Function In Producing Aromas and Flavors.”

YEAST NUTRIENT-  Assist the Wine Yeast in Producing a Complete and Rapid Fermentation . The Addition of Yeast Nutrient is Recommended For Use In All Fermentations. This Addition to Yeast Provides a Source of Nitrogen For the Yeast to Utilize During the Fermentation Process.  Nitrogen and Ammonia is Typically Found to Be Naturally Lacking In Most Wine Musts.

  • Nitrogen Compounds- Stuck and Sluggish Fermentation Along With Sulfide Formation Are Common and  Associate With Deficiencies of Yeast Assimilating Nitrogen In the Must.  Knowledge of Nitrogen Status Is Important For Effective Fermentation Management. Nitrogen Compounds Ae Essential Macronutrients for Yeast and Are Required For Cell Growth.
  • Ammonia- The Form of Nitrogen Nutrition Most Easily Assimilated by Yeast. Wine Makers Supplement Nitrogen Deficient  Musts With Diammonium Phosphate at the Start or During Fermentation to Provide Adequate Nitrogen Levels.
    • Ammonia Analysis and Adjustments During f Fermentation may Be Beneficial to Minimize the Risk of a Fermentation Getting Stuck and Leading to Sulfide Formation.

“Newly Harvested Grapes Are Covered In Yeast/ Bloom, Who’s Only Job is Life is to Compromise the Skin and Convert Its Sugar.”

YEAST TERROIR- Each Region or Terroir is Made Up of Its Unique Yeast.  Often Referred to as Bio-Geography Each Site Host Different Microbial Populations.

  • Micro-Biome/ Floral Masses- Range of Fungi and Bacteria That Are Unique to a  Particular Vineyard. These Micro-Biomes Range From Region to Region and Sub-Region to Sub-Region and Are Influenced by Geography, Topography and Climate and Are the Basic For What is Referred to as Indigenous Yeast Populations.

SELECTING YEAST– Alcohol Tolerance of  Yeast is Important Factor to Address Before Choosing Yeast. If You Want a Fermentation to Go Smoothly You Don’t Want Yeast to Die Off From Elevated Alcohol Levels Before All Sugar Are Converted. Different Yeast Strains Have Different Profiles and Produce Different Aroma and Flavor In the Finished Wine.

  • Yeast and Grape Pairing Guilds are Available to Help Guide You Through the Yeast Selection Process.
  • Some Wine Makers Use the Same Yeast Strain In All Wine. There’s an Inherent Benefit to Knowing the Exact Behavior a Particular Yeast In Case Things Go Wrong. Cultured Yeast Give Wine Makers a Predictable Flavor Profile.
  • Different Yeast Are Used to Produce Different Outcomes; Fruity Aromas, Attractive Mouthfeel, Ability to Perform In High ABV., Produce Sediment That Will Quickly Settle.
  • Historically Yeast Die at 14% ABV., Now “Super” Yeasts Have Been Developed and Some Yeast Can Ferment Sugars Past 15% ABV.

WILD/ NATURAL/ NATIVE, INDIGENOUS YEASTS– Naturally Existing Yeast In the Air and On Vegetation.

  • Wild Yeast Likes to Attach Itself to Surfaces In the Vineyard and Winery. If You Leave Your Grapes Carelessly Around After Harvest Wild Yeast Will Colonize and Start to Consume Sugars.
  • Yeast Find Strength In Numbers.  Is There a Yeast Harvest Date, or a Certain Time During Harvest When the Yeast Population is Greater and it Would Be More Advantageous to Harvest Grapes For a Wild/ Native Yeast Fermentation.
  • Getting Fermentation Started With Native Yeast- Crushing Grapes In Bucket In Middle of Vineyard and Let the Native Yeast Start Fermentation and Then Using the “Native Starter Yeast” to Inoculate the Main Vats of Grape Must.
  • Re-Yeasting- Killing Off the Native Yeast On the Grapes When They Are Brought Into the Winery and Reinoculating With a Cultured Yeast
  • WINE & PHILOSOPHY? “Do You Need to Use Native/ Wild Yeast Indigenous to the Grapes Region to Be Natural and Part of Its Terroir?”
    • “The True Representation of Terroir Needs to Include Native Yeast. The Act of Killing Off Native Yeast Only to Inoculate With a Cultured Yeast is Unnatural. As a Result One Winery’s Wine Can Taste Completely Different From Their Neighbors Estate Wine Even if the Terroir and Grapes and Identical.”

FERAL YEAST- Term to Describe Yeast That Exists In the Winery.

  • Feral Yeast Lives On Wood On Ceilings, In Barrels and On Equipment. Yeast Could Have Come From Cultivated Yeast or Wild Yeast That Blew In Off the Vineyard or Carried On Hands and Clothing. Feral Yeast Plays a Role In Spontaneous Fermentation.
  • Native Yeast Usually Can Start a Fermentation but Have a Difficult Time Finishing Because They’re Less Hardy and Ethanol Tolerate. With Native Yeast Wine Maker Don’t Have Complete Control of Fermentation, But This Does Add Complexity and Nuances to Wine (Burgundian Method), Indigenous, Die Off Between 6% ABV.- 17% ABV.

SPONTANEOUS FERMENTATION

  • There’s a Unpredictable Nature to Spontaneous Fermentation; Low Resistant to Higher ABV., Usually Smaller Number of Yeast Cells and Takes Longer to Colonize and Complete Fermentation, Some Wild Yeast Can Produce off Scents and Esters.

SEQUENTIAL FERMENTATION

CULTURED YEASTS- Raised In Lab, Reliable, Withstands +ABV., +Pressure

  • Fresh Cultured Yeast
  • Indigenous
  • Freeze Dried Yeast
  • Frozen Yeast
  • TYPES Of YEASTS
    • 71B-1122–  Indigenous/ Isolated– Narbonne
    • Actiflore Yeast
    • Barolo
    • Bourgovin RC 212–  Indigenous/ Isolated– Burgundy
    • Candida Stellata
    • BDX- 
    • BM 4X4–  Indigenous/ Isolated– Italy-Montalcin0
    • CK S102-  Indigenous/ Isolated– Loire Valley
    • CSM-  
    • D254- 
    • EC-1118-  Indigenous/ Isolated– Champagne, Original “Prise de Mousse”. Isolated In
      • Strong Competitive Character/ Ability to Ferment at Low Temperature, Good Flocculation and Excellent Alcohol Tolerance.
    • Hansenula
    • HD s135/ H s62-
    • ICV-D47–  Indigenous/ Isolated– Rhone Valley
    • Kloeckera Apiculata
    • Lachancia Thermotolerans-   Indigenous/ Isolated– Rioja, Spain
    • Metschnikovia Fructicola
    • Metschnikowia Pulcherrima
    • Montrachet–
    • NDA 21-   Indigenous/ Isolated– Sicily
    • Pichia Membranaefaciens
    • RC-
    • RC212-
    • QA23–  Indigenous/ Isolated– Portugal
    • Q5-
    • Saccharomyces Cerevisiae– AW4/ BV7/ CL23/ CR51/ CY17/ MA33/ R56/ SN9/ VR21
    • Tourlaspora Delbrueckii
    • UV43-
    • William Selyem
    • Zymaflore Yeast
  • YEAST PRODUCERS/ DISTRIBUTORS
    • Lallemand Yeast Manufactures(Lavin)
    • Red Star
    • White Labs
    • Wyeast
    • Vintner’s Harvest

INOCULATION– Adding Cultured Yeast to Juice or Must to Initiate Fermentation By Liquid Yeast, Hydrated Yeast Pack, Natural.

  • How to Inoculate a Must- Get a Container of Water and Add the Yeast to Get Your Starter Culture Yeast Going and Add Some Juice to That to Get it Acclimated. Then Add Some to Each of the Tanks You Want to Inoculate. (This is Just the Beginning, Some the Juice is Inoculated Another Level of Detail and Attention is Needed to Make Sure Things Are Going Well During the Fermentation Process.)
  • Yeast Take Anywhere From 12 to 26 Hours to Start to Show Fermentation After Inoculation.
  • Pied de Cuve-(Winemaking Equivalent of Starter Yeast)– Building a Small Population of Viable and Strong Yeast.  Having Active Yeast On Hand Assists In the Winemaker to Complete a Quick, Fast, Clean and Strong Fermentation Without Volatility, Reduction and Spoilage Bacteria.  The Process is to Pick a Series of Grapes and Start a Mini-Ferentaion a Week Before Your Primary Fermentation is to Begin.  When You Want to Commence Your Main Fermentation You Will Have Activated Yeast On Hand That You Can Add.

SPECIFIC GRAVITY- Ratio That States How Dense a Fluid is Compared to the Density of Water. Reading Specific Gravity Will Help Tell How Much Abv. the Wine Will Be if Allowed to Ferment Completely Dry.

  • Fluid That’s More Dense Than Water Will Have a Specific Gravity of More Than 1.0.
  • Fluid That’s Less Dense Than Water Will Have a Specific Gravity of Less Than 1.0.
  • Sugar is More Dense Than Water So Unfermented Grape Juice is More Than 1.0.
  • Alcohol is Less Dense Than Water So Fermented Grape Juice is Less Than 1.0.

MUST GRAVITY- Percentage of Sugar vs. Alcohol During Fermentation.

  • Hydrometer- Instrument Used to Measure the Relative Density of Liquids or Solution/ Specify the Must Gravity During Fermentation.
  • Usually Made of Glass and Consists of a Cylindrical Stem and a Bulb Weighted With Mercury of Lead Shot to Make it Float Upright.
  • Multiple Readings Should Be Taken to Confirm Fermentation Has Completed.
  • Reading Fluctuate as the Temperature Changes and Corrections Are Needed.

BLENDING YEAST AND WINE- Winemakers Often Will:

  • A) Use Different Yeasts On Batches of the Same Must and Blend the Batches Together Later.
  • B) Blend Different Yeast Together In a Starter and Inoculate the Wine With the Mix or the Two Yeasts.

High Sugar, High Alcohol Fermentation

  • These Fermentation Environment Are Not Ideal and It’s Hard For Yeast to Function Properly. In the Cases Special Yeast/ Special Attention is Needed For Fermentation.
  • Stressed Out Yeast During Fermentation Under These Circumstances Produce Other Compounds That Aren’t Ideal…Hydrogen Sulfide.

YEAST ADDITIONS/ NUTRITION/ PROTECTION/ FERMENTATION AIDS

  • Added to White Grapes After Pressing, Adding to Red Grapes After Maceration.
  • Combination of Growth and Survival Factors, a Yeast Perpetration For Use In Active Dry Yeast.
  • DAP. Diammonium Phosphate/ Water Soluble Ammonium Phosphate Salt.
    • Used to Prevent or Fix Fermentation Issues. Sometimes the Yeast Tires Out Before Finishing and Becomes Stuck.
  • Rehydration Water For a Strong Fermentation Finish.

Yeast Fermentation Cycle

  • Fermentation Period- WHITE= to 21 Days @65°,  RED= to 10 Days @80°
  • Lag Phase- Period When Yeast is Adapting or Orienting to Its New Must Environment of Sugar, Oxygen and Nutrients. Lag Phase Can Last a Few Hours to a Day.
  • Rapid Growth Phase- Period When Yeast Explode and Multiple by Absorbing Available Oxygen and Nutrients. Adding a Small Amount of Yeast is Un-Proportionate to How Many Yeast are Needed to Complete Fermentation.
  • Stationary Phase- At Some Point Yeast Absorb All Available Oxygen and Lose Their Ability to Multiple. Stationary Phase Last Most of Fermentation Process and is When it Produces Alcohol.  Yeast Now Turn to Sugar to Live and Produce Alcohol Along With Co2 and Heat as a Byproduct.
  • Decline Phase- Period As Sugar Runs Out and Alcohol Levels Get to a Certain Point Yeast Can’t Fermentation and Die.
  • Stuck Phase- When a Fermentation Has Stopped There Are 2 Outcomes…
    • No More Sugar and Wine Completely Dry.
    • Yeast Didn’t Finish Fermentation, Sugar is Still Present But Alcohol Levels Have Killed Yeast Off and You Have a Struck Fermentation.
  • Finished Fermentation- When All the Yeast Has Turned All the Sugar to Alcohol, Fermentation is Completed.

ESTERS– Ethyl Esters and Acataine Esters. Introduced Into Wine During Fermentation by Yeast Biologically In Excess of Their Equilibrium Concentration.

**Refer to “WINE EVALUATION/ Aroma/ Esters” For Detailed Information.

ENZYMES– Catalysts For Specific Biochemical Reactions

  • 12 Different Enzymes Involved In Fermentation
  • Enzyme Products-
    • Preserves the Freshness and Aromatic Qualities of the Grapes.
    • Designed Primarily For Settling Juice and Have the Added Ability to Improve Filtration Rates.
    • Increase Color Extraction and Stabilty
    • Increase Free Terpenes
  • Yeast Application- Added Directly to the Grapes Prior to the Press.  Added to the Tank Prior to Fermention

3) SUGAR– General Name For Sweet, Short-Chained, Soluble Carbohydrates. Sugars Come In Various Types and are Derived From Different Sources.

  • Amount of Sugars In Grapes Varies by Ripeness.
  • Not All Sugars Are Metabolized by Yeast at the Same Time or at Same Rate.
  • Different Sugars Have Different Taste Profiles and Sweetness Levels.
  • FERMENTABLE SUGARS IN GRAPES
    • Glucose   |   Fructose
  • Usually Glucose and Fructose Levels In Grapes Are Even.
  • Over-Ripe Grape Become Unbalanced and Contain Higher Levels of Fructose.
  • Fructose Taste Twice as Sweet as Glucose.
  • Glucose is the First Sugar Metabolized By Yeast.
  • NON-FERMENTABLE SUGARS IN GRAPES
    • Arabinose   |   Rhamnose   |    Xylose
  • These Sugars Aren’t Metabolized by Yeast and Are Present After Fermentation In Very Small Amounts.

4) OXIDATION

OXIDATION– Traditional Vinification Where Wines Are Exposed to Oxygen During Wine Making Processes. (Fermentation, Racking, Barrel Aging),Wine Exposed to Air Causes Chemical Reactions and Leads to Accelerated Deterioration, +Air Exposure, Converts Acetaldehyde to Acetic Acid.

  • Ethanol, Polyphenols, Organic Compounds Oxidize In Presence of Oxygen
  • Sotolon- Compound 3-Hydroxy-4,5-Dimethyl-2-(5H)-Furanone, From From Acetaldehyde and is Found In Oxidized and Botrytized Wines.

OXIDATIVE- A Wine That is Effected by Oxidation, Either Deliberately or Over the Course of Time.

OXIDIZED- Past Tense, a Wine That Has Become Oxidized.

“Oxidation is a Fault, Oxidative is a Style.”

OXIDATIVE WINEMAKING- Making Wine With the Deliberate Exposure to Oxygen. Depending On the Timing and Length of Exposure to Oxygen Can Have Many Effects On the Finished Wine.

  • Do You Let the Juice Oxidize Right Away or Do You Protect it From Oxygen?  A Little Oxygen During Wine Making Process is Good, But Uncontrolled Oxidation is Bad. You Need a Little Oxygen to Create Aldehyde and Form Complexed Phenolic and Tannin.
  • Excessive Oxidation of Juice Before Fermentation or Wine After Fermentation Prior to Barreling Potentially Volatilizes and Oxidizes Aromas Out of the Wine.
  • While In Juice Form Oxygen Should Be Embraced and Absorbed, Its Enhances the Yeast During Fermentation. Post Fermentation Wine Should Be Protected at All Times With Reductive Environment or Inert Gas.
  • Oxygen Exposure is a Force That Drives Volatile Acid Production, Acetaldehyde Production, Depletion of Free Sulfur Dioxide, and Reduction of Shelf Life.
  • Too Much Oxygen Exposure Can Lead to a Wine Which Looses Its Aroma and  Freshness.
  • Too Little Oxygen Can Produce a Reductive Wine With Minimal Expression.
    • **Refer to “VINIFICATION/ Fermentation/ Reduction” For Detailed Information On  Reduction.
  • PRE-FERMENTATION OXIDATION-  Winemakers Will Encourage a Certain Amount of Oxygen In the Must or Brown-Juicing the Must Prior to Fermentation.
    • This is Done In an Effort to Oxidize the Phenolics That Will Be Extracted During the Fermentation Process.  The Thought is if These Phenolics or Not Oxridized Out of the Must They Will Express Themselves Negatively at a Later Time Often After Bottling.
    • **Refer to “WINE FAULTS/ Oxidation” For Detailed Information.
  • WAYS To EXPOSE WINE To OXYGEN
    • Pumpover
    • Punch Downs
    • Fermenation
    • Racking
  • REGIONS/ WINES USING OXIDATIVE VINICULTURE
    • Jura AOC.
    • Jerez DO.
  • VARIETIES SENSITIVE To OXIDATION
    • White= Marsanne, Rousanne, Chenin Blanc, Chardonnay
    • Red= Pinot Noir
  • OXIDIZED WINE EVALUATION
    • Sight: Amber-Brown
    • Aroma: Sulfur Caramel
    • Palate:
    • Structure: High Acid
      • FOOD PAIRING… Licking Envelops
      • CHEESE PAIRING…

MICRO-OXYGENATION-  Process of Introducing Small Precise Amounts of Oxygen to Wine In Accelerated, Controlled Manner. Micro-Oxygenation Promotes Binding of Harsh Phenolics Making Less Astringent All In an Effort to Make the Wine More Approachable at an Earlier Age.

“Improper Oxygen Management is One of the Biggest Causes of Wine Quality Degradation.”

5) REDUCTION

REDUCTIVE– Catch-All Phrase For Wine Which Has Captured Hydrogen Sulfide/ Volatile Sulfur Compounds or Other Related Compounds Which Are Produced by Fermentation.

“Reduction Can Be Seen as Positive Style/ Methodology But Also as a Wine Fault.”

  • REDUCTIVE WINEMAKING- Vinification Technique or Handling the Wine In a Reductive Manner Where Extra Precautions Are Taken to Produce Wine In the Absence of Oxygen. Reduction is Caused by Yeasts That Interact With Sulphur-Containing Compounds and Amino-Acids and is Crossed by Complex Reactions During Winemaking and Subsequent Maturation.
  • VINICULTURE- (Closed Stainless Steel, Carbonic Maceration)
    • Intended to Maximize Freshness, Fruit Flavors and Acidity of Wine.
    • Reduction is the Presence of Volatile Sulfur Compound In Wine.
    • Reduction is Winemaking With the Restriction of Oxygen and is Brought Out More With Low Nutrigen Must.
    • Reduction/ Oxidation Are Two Different Chemical Processes That Complement Each Other.
    • Nobel Reductions- Often Refer to In Chablis, The Slight Reduction Character That Give the Wine a Match-Stick and Minerality Sense.

“The Fermentation is a Reductive Process, But the Handling of the Must You Can Choose to Be More Oxidative or Reductive.”

  • POSITIVE vs. NEGATIVE REDUCTION
    • Certain Amounts of Reductive Compounds Are Subjective and Seen as Subjective or a Nuance to the Wine.
    • Positive Aromas– Flint, Smoke, Minerality
    • WINES THAT SEE POSITIVE REDUCTION
      • Chablis
      • White Burgundy
  • REDUCTION As A WINE FLAW
    • If a Fermentation is Out of Balance and is Producing Move Hydrogen Sulfide/ H2O Than the Fermentation Gases/ C02 Can Carry Away the Hydrogen Sulfide/ H2O Will Accumulate and the Wine Will Start to Have Negative Smell.
    • Under Certain Condition During Fermentation Its Common if the Yeast Isn’t Fermenting Properly or Going Through a Sluggish Fermentation or Yeast Doesn’t Have Enough Nutrition Yeast Can Release Sulfur Based Compounds That Lead to Reduction.
    • Through the Winemaking Process or During Storage You Can See the Releases of Sulfur Based Compounds.
    • Wine Tend to Be More Reductive Under Screw-Cap. When Using a Closure With Less Ingress the Greater Potential For Reduction.
    • There is the Possibility For +100 Volatile Sulfur Compounds In wine
    • Reductive Aromas/ Hydrogen Sulfide Descriptors-
      • Match Stick, Rotten Egg, Burnt Rubber, Rotting Vegetable/ Cabbage, Rotting Meat
      • These Notes Are Come From the Negative Influence of Hydrogen Sulfide and Lead to Mercaptans.
    • Mercaptans– Type of Sulfur, By-Product of Oxidation, There Are Mercaptans That Negatively Effect and Positive On Wine
  • DEMYSTIFYING PROCEDURE~ ~Reduction~
    • “If the Odors On of the Wine Aren’t Too Bad Letting the Wine Breath or Decanting the Wine Will Help In the Oxidation of the Volatile Sulphur Compounds and Minimize the Faults.”

6) OTHER TOPIC Of VINICULTURE-FERMENTATION

“After Fermentation Wine is a Solution That’s Very Stable and Toxic to Any Micro-Organism. Wine Will Never Go Back or Kill Someone, it Just Turns to Vinegar.”

CRAFTING AROMAS DURING WINEMAKING
During the Wine Making Process the Wine Maker Makes Choices to Avoid Aromas or Intensify Others.

  • FACTORS INFLUENCING AROMAS
    • Ripeness of Fruit
    • Choice of Yeast
    • Fermentation Vessel
    • Aging Vessel
    • Grape Varietal
    • Temperature During Fermentation
      • Cold- Emphasizes Fruit Characters
      • Warm- Emphasizes Earthy, Mineral Characters
      • Hot- Too Hot and Aromas Are “Blown Off”

“Stainless Steel is a “Dead” Material, Where as Oak and Concrete are “Full of Life.”

FERMENTATION VESSELS

BARREL FERMENTATION- Fermentation of Must/ Juice In an Oak Barrel.

  • VITICULTURE- Barrel Fermentation is Part of the “Burgundian Method”
    • ADVANTAGES– Highlights Texture, Flavor. Mouthfeel and Complexity of Wine
      • Good Integration of Oak Into Wine
      • More Pronounce Tannins/ Tannin Integration
      • Slower Fermentation Period

CONCRETE FERMENTATION- Fermentation of Must In a Concrete Vessel.

  • VITICULTURE- ADVANTAGES–
  • **Refer to “CONTAINERS/ Concrete Egg” For Detailed Information.

STAINLESS STEEL FERMENTATION-  Fermentation of Grape Juice In a Stainless Vessel.

  • VITICULTURE- ADVANTAGES– Adds Complexity, Preserves Primary Fruit Aromas and Flavors.
  • Contributes: Leanness, Crispness, Preserves Fruit and Acid.
  • Stainless Steel Fermentation Tanks are State of the Art With Temperature Controls That Make the Process Extremely Reliable and Precise to Control. Stainless Steel Fermentation Tanks Are Chilled Which Can Creates a Slow and Long Fermentation Period Which Lends Itself to Enhanced Complexity and Increased Aromatics.
  • Jacketed Fermentation Tank- Steel “Dimpled-Jacket” Wrapped Around Fermentation Tank. Jacketed-Tank Cooled by High Pressure Flow of Freon, Ammonia or Water That Flow Around In Coils. These Jacket Systems Ensure Continuous Precise Control of Temperature During Maceration and Fermentation. Most New Steel Fermentation Tanks Are Available With the “Jacket”, or Some “Jackets” Can Be Added to Older Tanks. Precise Control Over the Temperature During Fermentation is Extremely Important and Something That’s Watched In Detail.
  • Computer Assisted Fermentation-  Computer That Monitors the Temperature of the Fermentation Throught the Process and Can Raise of Lower the Temperature to Certain Level as the Process Progresses.
  • Roto Fermenter- Fully Automated Fermenter That’s Optimal For Winemakers Striving For Optimum Extraction of Colors and Tannins From Red Grapes.
  • Fermentation Lock- Devise That Attaches to Bung of the Barrel to Keep Air Out While Letting Carbon Dioxide to Seep Out During Fermentation.
  • STAINLESS STEEL TANK PRODUCERS
    • Aaqua Tools INC.      @Ranch Cordova, California
    • Algor     @Italy
    • La Garde     @Quebec, Canada
    • Quality Stainless Tanks     @Windsor, California
    • Sanitary Stainless Welding INC.     @Fresno, California
    • Santa Rosa Stainless Steel      @Santa Rosa, California
    • Schaefer Container System     @Atlanta, Georgia
    • Silver State Stainless INC.      @Mound House, Neveda
    • Spokane Industries    @Spokane, Washington
    • Stainless Fabrication INC.     @Springfield, Missouri
    • Westec     @Healdsburg, California

CARBONIC MACERATION/ Maceration Traditionelle/ Maceration Carbonique

  • Process Where Whole Grapes/ Bunches(Protected From Oxygen, Normally Under a Veil of Carbon Dioxide) Undertake an Intra-Cellualar Fermentation Due to Enzymatic Reaction Without the Action of Yeast.
  • The Technique  of Carbonic Maceration Has Been Used Inadvertently For Thousand of Years. It Wasn’t Until The 1930’s That Producers In France Started to Focus On the Process.
  • Process That  Occurs When Intact Bunches of Grapes Are Fermented In a Sealed Vat That Has Been Filled With Carbon Dioxide.  Newly Picked Uncrushed Bunches Are Put In Closed Vats With Carbon Dioxide. Grapes On Bottom Are Crushed by Weight as Fermentation Begins. Technique is Considered Reductive Wine Making.
  • Carbonic Maceration is an Intra-Cellular, Anaerobic, Enzymatic Metabolism Inside Each Berry and Produces Light Reds, Low Tannins (Minimizes Tannin Extraction), Intense Color, Fruity-Fresh Aromas. Carbon Dioxide is Trapped In Tank, and Grapes Bath In it. During This Process Some Alcohol is Produced (2% ABV.) Along With a Range of Other Compounds That Affects a Wines Aromas and Flavors
  • Grapes Must Be Whole and Intact and Healthy Which Means Hand-Harvested In Whole Bunches In the Vineyard.
  • CARBONIC MACERATION- ~ADVANTAGES~
    • Producing Different Aromatic Elements
    • Reduction of Alice Acid
    • Increase Levels of Glycerol,\Softer Tannin Extraction
    • More Approachable Early On

SEMI-CARBONIC MACERATION- True Carbonic Maceration is Rare. In Most Cases Semi-Carbonic Maceration is Taking Place Where a Portion of the Crushed Grapes On the Bottom of the Vessel are Going Through Regular Fermentation While Carbonic Maceration is Happening Concurrently.

  • VARIETALS POSITIVLY EFFECTED By CARBONIC MACERATION
    • Gamay   |   Syrah
    • Garnacha   |   Cinsault
    • Pinotage   |   Pinot Noir
  • CLASSIS CARBONIC MACERATION WINES
    • Beaujolais AOC.   |   Chinon AOC.
    • Jumilla DO.   |   Rioja DO.
    • Paarl DO

WHOLE BUNCH/ CLUSTER FERMENTATION/ No Destemming-  Fermentation Grape Clusters Without Destemming. This Adds Structure, Back Bone, Tannins, Aromatic Lift, Spiciness, Absorbs Abv. and Complexity, Drinkability (BURGUNDIAN METHOD)

**Refer to “PRE-FERMENTATION/ Stem Inclusion” For Additional Information.

ARRESTED FERMENTATION– Stoping Yeast From Completely Converting Sugars to Alcohol During Fermentation Process.

VINICULTURE- Dry to Sweet Wine Styles All Achieved by Manipulation of Fermentation.

  • WAYS To STOP FERMENTATION
    • Addition of Heat   |   Adding Sulfur Dioxide
    • Adding Carbon Dioxide   |   Adding Pressure
    • Adding Potassium Sorbate   |   Adding Sorbic Acid
    • Adding Neutral Spirit/ Fortify/ Mutage

STUCK FERMENTATION- Fermentation That Has Stopped Due to Yeast Prematurely Dying, Usually Due to High Fermentation Temperatures, Yeast Nutrient Deficiency, or Excessive High Sugar Content, +Abv.

DECLINING ALCOHOL– During Fermentation Using Open Top Fermenters There Can Be an Evaporation of Alcohol by as Much as 1/2 of a Percent.

**Refer to “VINICULTURE/ Post Fermentation” For Detailed Information On Declining Alcohol.

**Refer to “BIBLIOGRAPHY/ Sources” For Details On Scholarly Works Referenced.