The Winery
Turning grapes into wine
Objectives
¤ Science of Wine
¤ General Winery Operations
¤ Making of White Wine
¤ Making of Red Wine
¤ Making of Sparkling Wine
SCIENCE OF WINE
The Mighty Yeast
¤ Saccharomyces cerevisiae (sugar
fungus)
¤  Similar to bread, beer, and distilled beverage yeast strains
¤  There are many varieties available commercially that
influence the wine…
¤ Natural fermentation
¤  Wild yeasts found on the grape skins
Sulphur
¤ Two types in wine: Sulfides and Sulfites
¤ Sulfides (i.e. H2S) are the product of
fermentation and cause odor in wine (>1
ppb – 1 drop in 50,000 litres)
¤ Sulfites (SO2) are used to preserve wine
by preventing the growth of spoilage
microbe
Commercial vs. Wild
Commercial - Modern
¤  Reproducible & predictable
fermentation characteristics
¤  Vigorous fermentation
¤  Complete fermentation
¤  Good alcohol tolerance (up to
18%)
¤  Minimal off flavours (e.g. H2S)
¤  SO2 tolerance
Wild – pre-industrial revolution
¤  Produce compounds that
create off flavours
¤  Most wild yeast tolerate
only 4-6% ethanol (only a
few up 10%)
¤  They are unpredictable
¤  SO2 sensitive
Requirements for Good Fermentation
¤  Sugar – wine can use both glucose, fructose (sugar in grapes) and sucrose (table
sugar)
¤  Nitrogen – dissolved in must and found naturally in grape juice, but require
additional from diammonium phosphate (DAP)
¤  Vitamins – yeast can produce all the necessary vitamins except for biotin (from
grape)
¤  Minerals – Varies, but predominately phosphurus
¤  Low pH – Grape juice is acidic (pH of 3-4)
¤  Moderate temperature – yeast can survive between 20-40°C
¤  Ethanol – The threshold is below 16-18%
Yeast Growth
¤  Yeast reproduce by budding
¤  After producing about 12 buds,
the yeast cell dies
¤  When yeast are added to the
juice, there is a lag in activity
¤  However, growth is exponential
until an unfavorable event
¤  Some cells will survive, so care
later to not reinitialize
ferementation
Yeast Activity
Fermentation
C6H12O6 è2CH3CH2OH + 2CO2 [56 kcal]
Glucose
2 ethanol
2 carbon
dioxide
¤  Fermentation is the conversion of sugar into alcohol and
carbon dioxide, with the release of energy
¤  Less than ½ of the energy is used by the cell and the remaining
(34 kcal) is lost as heat
¤  A reduction of 1° Brix, results in a temperature increase of 1.3°C
Ethanol Yield
¤ About 94% of sugar is converted to
ethanol and carbon dioxide
¤ Approximate yield of ethanol is 55% by
volume, so…
¤  Juice at 20°Brix (20% sugar) will yield…
¤  11% ethanol by volume
Fermentation Time
¤ Fermentation can take a few days to a few
weeks
¤ Temperature is the most influential factor
¤  The higher the faster
¤ Whites: 12-15°C
¤ Reds: 20-30°C
¤ Varietals can also influence fermentation times
Malolactic Fermentation (ML)
¤ Fermentation of the malic acid to lactic acid
¤  Used in many reds & some chardonnay
¤ ML fermentation reduces the acidity of the
wine, generates CO2, and contributes a buttery
flavor.
¤ Occurs naturally in some wines, and almost
always in wood tanks & barrels
¤ Can be prevented by SO2 or sterile filtration
From Wine to Vinegar
¤ Acetobacter is the bacterium responsible for
the conversion of wine to vinegar
¤ Converts ethanol into acetic acid & ethyl
acetate when oxygen is present
¤ Prevent includes:
¤  Oxygen free environments
¤  Ethanol at 14% or higher
¤  SO2
Brett
¤  Brettanomyces is a wild yeast that contributes a sweaty,
leathery smell to wine
¤  Hard to control as it is ethanol tolerant and likes the same
conditions as wine yeast
¤  Some people like “brett” character and can be part of
traditional wine
¤  Typically, found in old equipment and unsterile
environments
¤  Can be controlled with SO2 & filtration at bottling
GENERAL WINERY OPERATIONS
Winery Overview
Processes in the Winery
1. 
2. 
3. 
4. 
5. 
6. 
7. 
8. 
9. 
10. 
Receiving Fruit
Crushing
Must Adjustments
Pressing (for whites)
Fermentation (1st & Malolactic)
Pressing (for reds)
Settling
Fining
Filtration
Bottling
When (Receiving Fruit)
¤ The Vineyard Manager will balance against
weather and labour
¤ The Winemaker is concerned with capacity
and accommodating the harvest into the cellar
¤ Both are concerned with optimal quality
¤ A ton of grapes will yield approximately 60
cases of wine and acre of vines can product
between 2-8 tons
Crushing
• Free Run
• Amount Crush (carbonic)
• Cold Stabilization
Must Adjustments
¤ Chaptalization is the addition of sugar to
increase the alcohol content of the wine
¤  Prohibited in California & Southern Europe
¤ Acidity adjustment is common in hotter
regions (i.e. California, etc.) and is
accomplished with the addition of
tartaric acid
Pressing
¤ Pressing Methods
¤  Apply force to whole fruit to render more juice
¤  Foot stomping (oldest method)
¤  Screw press
¤  Bladder
¤ Free run I juice obtain without pressing
and is consider the highest quality
¤ Fractional pressing is the separate yields
of increase presses of the must
Fermentation (Preparation)
¤ Inoculation of juice or must with a yeast slurry
¤  Yeast are rehydrated in water and sugar mixture to prepare
for fermentation
¤  Yeast slurry is added to juice or must, but should be within
5°C to avoid shock
¤ Primary fermentation is done in sanitary
contains such as:
¤  Stainless Steel (common in modern facilities)
¤  Plastic tanks
¤  Wooden tanks
¤  Concrete lined with epoxy
Fermentation (Managing)
¤  Temperature must be managed by either air cooling or
refrigeration jackets.
¤  Cooler temperatures will yield a fruiter wine
¤  CO2 needs to managed at this time through airlock and
ventilation – CO2 is dangerous and has killed many in
wineries
¤  White fermentation is kept at 12-15°C for 10-30 days
¤  Red fermentation is kept at 20-30°C for 4-12 days
Barrel Fermentation & Aging
¤ Most reds and chardonnay are transferred to
barrels for fermentation and aging
¤ Malolactic fermentation (ML) is often harbored
in wood
¤ Barrels lose influence over time and due to the
expense new and old barrel are used in
different ratios according to the winemaker’s
preference
Barrel Characteristics
¤  Barrels are typically around 220 litres
¤  French Oak provides more subtle flavours and is an Old
World style (barrels range from $800-2500)
¤  Most forest were planted in the of Napoleon for shipbuilding
¤  American Oak has a stronger aspect to wine and
represents a New World flavour found in many American
& Australian wines (prices range from $400-1000)
¤  Toasting level also influences the character of the wine
(low, medium, medium+, high)
Settling
¤ Wine contains suspended particles (turbidity)
¤ Yeast will die and eventually settle to the
bottom of the tank and create a sediment
layer called lees
¤ Wine will be racked off lees to help clear the
wine
¤ Wine can become completely clear, but could
take months or years depending on the size of
the tank
Fining
¤  Even after multiple rackings wine may still be hazy because of
the following:
¤  Proteins
¤  Polysaccharides
¤  Microbial residues
¤  Different agents are added to bind to the particles and
increase the settling process such as:
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Egg Whites (common for reds in France)
Gelatin (whites, derived from animal fat)
Casein (milk protein)
Bentonite (clay)
Issinglass (fish bladders)
Other items such as blood, moss, polymers, etc.
Filtration
¤ Most wines are filtered multiple time
¤ Filtration is identified by micron (μ) size
of the filter medium
¤  A micron is a micrometre or 1/1,000,000 m
¤  A human hair is 10μ
¤ Filters are either pad, cartridge, or
diatomaceous earth (DE)
Bottling
¤ Decision of whether to sterile filter (.45μ) the
wine
¤ Steps of bottling include:
1. 
2. 
3. 
4. 
5. 
6. 
7. 
Wash/sterilize bottle
Fill bottle (sparge?)
Bottle closure
Seal cap (wax or shrink)
Label bottle
Pack bottle into case
Stock case
Bottling – Manual
¤  Inexpensive equipment
cost
¤  Very labour intensive
¤  50-100 cases for several
people in a typical day
¤  Not likely to sparge bottles
Bottling Monoblock
¤  Cost of monoblocks are
similar to that of a single
family house
¤  Bottles can be processed at
the rate of 50+ cases per
hour
¤  Challenge is maintain the
feeding and uploading of
the machine
¤  Takes expertise to maintain
this type of equipement
Making of White Wine
White Wine – Preparation
White Wine - Aging
Making of Red Wine
Red Wine – Preparation
Red Wine – Carbonic Maceration
¤ Whole clusters are placed into an airtight tank
filled with CO2
¤ No yeast is added, but the wild yeast on the
grapes are allowed to begin the fermentation
of the whole grape
¤ After 5-15 days at around 35°C, there is about a
3% alcohol content and the process follows as
normal red win production (except for barrel
aging)
Red Wine - Aging