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Introduction
UCD Grad
Making Wine for 19 years
In Rogue Valley for 10 years
Started Pallet Wine Company in Medford
This class will walk you through the process of making 5
gallons of finished (drinkable) wine while addressing
advanced topics and analysis.
Class Outline Grape Development and Composition
Grape pests and identification
Grape and Must handling procedures - adjustments
Winemaking Procedures
Microbiology
Fining and Filtering
Stabilization
Oak and Winemaking
Analysis Techniques
Tasting – good and bad wines
Grape Development Better grapes = better wine
Berry undergoes rapid cell division and acid accululates
Growth rate decreases and the berry “rests”
Veraison: Sugar (sucrose) translocated into the fruit, acids degrade and color begins to appear. Berry expands, flavor and aroma compounds build up.
Berry begins to dehydrate due to water loss and sugars/acids get concentrated.
Sugars in Grapes
Unusual, high levels of sucrose for fruit
Glucose (6-carbon sugar) and Fructose (5-carbon sugar)
Early= higher levels of glucose than fructose
Mid = 1:1 ratio
Late = higher levels of fructose than glucose
Fructose much sweeter than glucose
Yeast have a harder time with fructose (over ripe fruit)
Can differ by variety ( Chardonnay is an example of high fructose variety)
Acids in Grapes
L-Tartaric and L- Malic = 90% of acid in grapes
Tartaric uncommon in plants, malic is common
More vigor = reduced acid and higher pH
Acids increase in concentration until veraison, then decrease as
sugar accumulates. Malic decreases more rapidly in warm
climates.
Cool climate = higher acid at same sugar concentration as warm climate.
Hot climate = no malic acid at harvest
High Tartaric acid varieties = Reisling
High Malic acid varieties = Malbec and Pinot noir
Tartaric acid exists as a free acid (initially) and, over time,
combines with cations predominately K+. Can combine
with Ca++ and form a salt = calcium tartrate.
Sticks to equipment
Can change pH and TA
Good to know levels of Malic Acid at grape stage to aide with
MLF decisions
Phenolics
In white grapes, lower total phenolics and no anthocyanins
(color)
In red grapes, phenolics very significant group of organic
compounds
Color of wine
Taste
Aging properties
Most phenolics (red and white grapes) are in skins, some in
seeds
More concentrated in cooler climates
Cultural and Climatic Influences Any factor affecting grapevine growth and health will influence
ripening.
HighYield Increase may reduce the ability of the vine to mature the fruit or it’s potential
to produce subsequent crops.
In France, yield is viewed so important to quality, maximums have been set for Appellation Control regions.
Can be “offset” with improved fertilization, irrigation, pest control, etc.
Low Yield Not necessarily improve quality
Prolong shoot growth and leaf production
Increase shading
Depress acidity
Produce larger berries = skin: flesh ratio
Sunlight
Single most important climatic factor affecting berry
development.
Promotes anthocyanin synthesis
Essential for flavonol synthesis (phenolics- tannins)
Grassy, vegetative and herbaceous aromas are reduced by sun
exposure.
Sauvignon blanc, Semillon, Cabernet franc
Temperature
Influences enzymatic activity in grapes= speeds up ripening
Too hot = slows/stops
Grape Pests that Affect Wine Quality
Birds and Bees
Remove the crop
Compromise the crop
Bees “get in”
Acetobacter takes hold
Powdery Mildew
Botrytis Bunch Rot
Botrytis can be desirable in some
styles of winemaking
Virus
Mealybugs
Concerns of Making Wine from Mold Infected Fruit
Risk of moldy or compost type aromas
Aroma loss or alteration
Rapid must oxidation
Problematic Fermentations due to infection
Alteration of must color (browning)
Ready to Pick!!!!
Grape and Must Handling-
Adjustments
White Wine:
Sugar 22-24 degrees Brix
Titratable Acid = 6.5 – 8 g/L
pH less than 3.6
Red Wine:
Sugar 23 – 25 degrees Brix
Titratable Acid = 6 – 7.5 g/L
pH less than 3.7
Sugar Adjustments ºBrix * .55 = final % alcohol
Want over 12% alcohol for stability
Want less than 15% to ensure fermentation completeness
Need to adjust:
To bring sugars down:
C1V1 + C2V2 = C3V3
C = CONCENTRATION
V = VOLUME
Diluting sugars also dilutes acids and flavors – correct for acid
To bring sugars up: Add sugar- sucrose (table sugar) beet or cane is fine -
The formula to use is: S=0.125(v)(B-A)
Where S = the amount of sugar in pounds to add
0.125 = the amount of sugar in pounds needed to raise 1 gallon of juice 1 Brix degree
v = the volume of juice in gallons
B=desired final Brix value in degrees (usually 22)
A=current measured Brix value in degrees
For example: Your juice measures 17.5 ° Brix, and you have 10 gallons of juice.
You want a final Brix of 22 °. So, S=0.125(10)(22-17.5) or S=5.625 lbs. This means you need to add just less than 6 pounds of sugar to your juice prior to fermentation to get the desired Brixlevel.
Acid Adjustment
To bring acid up:
Add tartaric acid in g/L
1 g/L tartaric acid increases TA by 1 g/L
To bring acid down:
Add potassium carbonate
.62 g/L will reduce TA by 1 g/L
pH adjustment
No “formula”
Variety, vintage and buffering capacity
1g/L raise in TA lowers pH by .1
Important for picking decisions
Nitrogen Adjustments Important for yeast metabolism
Amino acids
Especially for compromised grapes
Added as ammonia (DAP)
Added as Superfood™
Fermaid K™ Contain yeast hulls, ammonia and vitamins
Does have sensory considerations
Referred to as Free alphaAmino Nitrogen or FAN
Need to supplement when levels fall below 140 mg/L
Can add 100 mg/L without testing
Enzymes
Pectic Enzymes
Break down pectins in skins and help with pressing
Release flavors in skins
Color X
Settling
Filtering
Add Sulfur Dioxide (SO2)
Kills “bad” bugs
Our yeast not as sensitive
Prevents browning
Protects juice and wine
Expressed in ppm
We will add 45 ppm to our juice using Campden tablets
1 tablet per gallon = 75ppm increase
5 gallons at 0ppm = add 3 tablets
Using Potassium Metabisulfite:
ppm increase * liters / 576 = grams of KMBS to add
Using a 6 % solution:
= 6 grams per 100 mls
= 60 grams per Liter
= 60,000 mg per Liter
Volume to adjust * increase/solution
Sulfur Dioxide = SO2
Widely used in food and wine industries
Chemical antioxidant and inhibitor of microbial activity
Prevents browning
Several compounds bind with SO2
Acetaldehyde
Sugars
Pigments
Bound vs. Free SO2
SO2 in wine occurs in two forms (species) bound and free
Sum of Bound and Free = total SO2 (legal limits for)
Rate of binding of SO2 is:
pH dependent
Temperature dependent
Wine dependent
Bound SO2
Constantly increasing over time
Free SO2
Constantly decreasing over time
Molecular SO2
Most important antimicrobial agent
Within the pH range of wine and juice, the amount of free
sulfur dioxide in the molecular form varies considerably.
Most winemakers aim for a .5 - .8 mg/L molecular form.
DEPENDS ON pH
Can be estimated using free SO2 measurements
Making White Wine
Pressing first
Transfer and sort grape clusters into press
No leaves
No moldy grapes
Spiders. Earwigs and dirt = OK
Press grapes until as dry as possible into two clean 5 gallon
buckets
Press slowly – too slow= low yield, too hard= bitter tannins from
seeds, stems and skins
Make adjustments now
Settling
Keep as cool as possible
Allow to settle overnight in cool place- don’t move around
Rack clear juice into 5 gallon carboy plus other glass
container- fill ¾ full only!
Put fermentation lock, breather cap on top.
Add Yeast
For white wine, we are using Champagne yeast
Need to hydrate and acclimate yeast
Wait a couple days to see bubbles
Monitor Brix and temps- temps go up fast!
Smell often
Will get very frothy
Keep clean
Top up container (s) near end of fermentation 0Brix
Keep flies out but let gas out- can explode if sealed
Allow to finish and age
When wine is “dry” , or when wine tastes good to you= time
to stop and protect wine.
Will begin to clarify
No CO2
No Air!
No heat
If wine is “done”
Rack off solids
Add SO2 at a rate of 50 ppm
Top carboy
Replace breather bung with a solid bung
Keep cool
Start thinking about bottling!!!
Stabilize prior to bottling
Tartrates will precipitate and form “wine diamonds”
Proteins will form a haze
Tartaric acid stabilization= get wine cold for 2 weeks (32
degrees F) and allow process to happen in carboy and not in
bottle
Proteins need a little bentonite to pull them out of solution
Just for looks of a clear wine
Add about 10 grams of bentonite and allow to settle.
Rack once more and bottle
Ageing, Stylistic Options and Finishing
Oak Chips – use carefully
Sur Lies (on lees) stylistic
Blending
More acid/Less acid
ML Fermentation
Bacterial Fermentation
Malic acid to Lactic Acid
Stabilizes the wine
Creates Butter Flavors
pH, temp and competition issues
If wine is sweet or not through ML,
must filter to avoid fermentation in
bottle.
Or drink it fast!!
Check S02 once more and make additions based on pH
SO2 and pH
Low pH requires much less sulfur dioxide (SO2) to be
“protected” pH 3.1 = 15 ppm
pH 3.3 = 20 ppm
pH 3.5 = 25 ppm
pH 3.7 = 35 ppm
pH 3.9 = 40ppm
This is the amount of SO2 that is present at bottling
Will lose a lot while transferring into bottles
Bottling
Transfer wine into clean glass (rack)
Use Nitrogen to displace air in bottle
Avoid Oxygen!!
Closure
Capsule
Label
Red Wine Making
A little different than whites
Process
Pick
Destem
Into fermenter
Adjust sugar, acid… if necessary
Keep warm
Add yeast
Hydrate like white wine
Begin to monitor
Punch Down
Keep Cap wet and clean
Distribute Heat
Allow air in
Extract tannins
Not too much
Taste often
Press
Drain wine first
Transfer skins and seeds to press
Gently press
Wine will be sweet
Wine will be tannic
Add press wine back to free run
Allow wine to settle
Rack off heavy solids
Continue to monitor
Will begin second fermentation (naturally)
Keep warm and topped up
Smell often
Add a little oak
Allow to age until it tastes good!
Finishing and bottling Wine
When wine is “ready”
Blending
Fining – if too bitter
Egg whites
Milk
Gelatin
Stabilize tartaric acids
Know your pH and adjust SO2 accordingly
Microbiology
Fining and Filtration
Stabilization
Oak and winemaking
Analysis Techniques
Tasting!!!!
Next Time:
Microbiology
Yeast –
Good
Wild vs. Engineered
Bacteria
Good
Bad
Acetobacter
Lactic acid bacteria
Mold – problem in beginning
Other - EtOH
Fining and Filtering
Process of clarifying and purifying
Added to the wine settles to bottom
Reacts with substance being removed
Each fining operation should be proceeded by bench trial
Can remove several compounds (flavor)
Can contaminate wine by addition
Can result in wine loss (additional racking)
Gelatin
Reduce tannin in astringent reds
Reacts with tannins through hydrogen bonding
Dose rate of .05 to .15 grams per Liter
Very easy to work with
Hydrate in water and stir into wine
Isinglass
Made from the swim bladder of certain fish
Made almost entirely of collagen
Very strong + charge to bind with - tannins
Used to remove phenolics and bitter tannins
Rather difficult to prepare but great results
Brilliant and soft finish
Rates of .02 to .1 gram per Liter
Milk and Casein Traditional for white wines to remove bitterness, harshness,
off flavors and lightening color
Skim milk (or need to remove the surface cream)
Powdered milk
Rate of up to about 1%
Casein needs to be made alkaline prior to adding to an acidic wine.
Dissolve casein in half its weight in potassium carbonate
Rate of about .05- .3 grams per Liter
Egg-white or albumen
Used to remove harsh tannins
Very popular method
Break eggs into aluminum bowl and add a pinch of salt. Wisk
eggs (not too foamy) and pour into mixing wine.
Usual dose is one to three eggs per 200 liters of wine.
PVPP
Poly-vinyl -poly –pyrrolidone
Synthetic material
Used in white wines to adsorb phenolics
Used to correct for pinking and browning
Insoluble in wine
Very $$
.2 to .5 grams per liter
Fining trials
Use a bench trial to determine rate
6% solution
100 mls of wine to treat
Filtering
Different pore sizes for filtration
10 micron = clarify
5 micron = polish
1 micron = prefilter
.45 micron = sterile filtration
Absolute vs. differential
Oak and winemaking
Analysis Techniques
Measuring Sugar Refractometer
Measures the bending of light
Use until alcohol is produced
Cost about $30 (look on eBay)
Great to take into the vineyard
Hydrometer
Measures specific gravity – how thick
Different scales
Brix scale = -2 to 30
Need about 150 mls per test (can pour juice back into fermenter)
Sugars
CliniTestTablets
Easy to use- made to measure sugar in urine
Very accurate in white wine
Red wine needs to be decolorized for easier reading
Use carbon or pvpp
.5 mls of sample (5 drops) and 1 pill. Sample gets hot when
reaction occurs.
Orange= sweet
Blue = dry
pH
Test strips range from 2.5 – 4.5
Small hand held = $20
Important to know pH
Titratable Acidity (TA)
Acid test kits
Reported in g/L or g/100ml
6.5 g/L or .65g/100 ml
Important to degas sample
SO2
Tirets test kits at Grains Beans etc.
Nielson Research Corporation
245 South Grape Street
Medford, OR 97501
(541)770-5678
Malo Lactic Fermentation
Will stall if wine gets too cold and finish in the spring
Will see bubbles in wine while fermenting
Should take about 8 weeks to complete
Can test with paper chromotography
Misc. Analysis
Volatile Acidity (VA) = amount of vinegar
Hydrogen Sulfide (H2S) = stinky, rotten egg
Alcohol (Ethanol)
Making a Port Style wine
Eliminates the need for filtering
Alcohol protects against microbe growth
Use same formula as sugar dilution:
C1V2 = C2V2
C= concentration (sugar or alcohol)
V = Volume
Adding sugar and alcohol
If wine is “ dry” add about 6 pounds of sugar to 5 gallons of
wine (add less if wine is a bit sweet)
Add about ½ gallon of high proof alcohol
C1V1 + C2V2 = C3V3
Tasting Wines
Color
Clarity
Aroma
Taste
Finish
See you next year
GOOD LUCK!!!
