2010 advanced winemaking class

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Linda Donovan

541.621.1589

lindasuedonovan@aol.com

2010 Home Winemaking Class

Advanced Topics

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!!!

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