Copyright 1999
APPENDIX A
STEP BY STEP WINEMAKING
In southern California, the annual grape crushes usually
starts in mid August and ends in early October.
Many factors influence grape ripening time including: grape
variety, temperature, soils, irrigation practice, sun light, etc.
FRUIT
"Wine is made in the vineyard," and high quality
wine can only be made from quality fruit.
When grapes are picked too early, the wine may be high in acid,
low in alcohol and lack fruit flavors and aromas.
When grapes are picked too late, the wine is often low in acid,
high in alcohol and has stewed fruit, raisin or prune flavors.
"Second crop"fruit often makes poor quality wine.
Professional winemakers get 150 to 180 gallons per ton, but home
winemakers seldom get more than 140 to 150 gallons.
Bulk wine containers must be topped up regularly and kept
completely full, so winemakers always produce extra wine.
Nominal Sugar Levels
17 to 19 Brix for sparkling wine.
19 to 22 Brix for blush and light white wines.
22 to 24 Brix for Chardonnay and Sauvignon Blanc.
23 to 25 Brix for most red wines.
GRAPE PROCESSING
Grapes can deteriorate quickly on a hot day.
Boxes of picked grapes should not be left in the hot sun.
Grapes should be moved to the winemaking area quickly.
Winemakers prefer fruit picked early in the morning when the
grapes are cold.
Crusher
For most home winemakers, a hand crank crusher is the most
practical method of crushing fruit. Both single and double roller
crushers work well.
Good machines can be cranked easily, but poorly designed and
poorly constructed machines are often difficult to turn.
Power crusher/stemmers crush the grapes and remove the stems in
one simple, fast operation. Removing the stems from white grapes
is not necessary if the grapes will be pressed immediately (stems
make pressing easier).
Stems can be removed from red fermentations by hand using the
following technique.
(1) Place a clean, plastic milk crate on top of a clean, plastic
trash can.
(2) Place a few pounds of crushed fruit in the bottom of the milk
crate and use a scrubbing motion. (3) The crushed fruit will drop
through the crate.
(4) Discard the stems from the crate and repeat the process.
Sulfur Dioxide (SO2)
Making quality table wine without using small quantities of
sulfur dioxide is difficult.
Sulfur dioxide helps control native yeast and bacteria.
Sulfur dioxide also reduces oxidation of the must and wine.
Usually, about 35 milligrams per liter of sulfur dioxide is added
when the grapes are crushed. One-half level teaspoon of sulfite
powder in 100 pounds of grapes is the correct amount.
The sulfite should be dissolved in a small amount of water and
then stirred into the crushed grapes.
Press
Small quantities of red wine can be made without a press, but
a wine press is necessary to make white wine.
The following procedure works well with small, vertical basket
presses.
(1) Fill the basket, add the top plates, blocks and press head.
(2) Apply a small amount of pressure until the liquid flows.
(3) When the flow decreases, increase the pressure.
(4) Excessive foam between the basket slats show pressing is
being done too quickly.
(5) When the flow stops, disassemble the press, crumble the press
cake and repress.
Most home winemakers crumble the press cake two or three times
when pressing expensive grapes.
Ratchet type basket presses can produce high pressures, but high
pressures often produce harsh, bitter wines.
Moderate pressures are desirable, and the fruit should be pressed
slowly.
JUICE AND MUST CORRECTIONS
Acid content (titratable acid) strongly influences the taste
of the wine.
Wine can taste flat and insipid when the acid content is too low.
Wine tastes too tart when the acid is too high.
Grapes grown in warm areas are often low in titratable acid.
Titratable acid should be between 0.65 and 0.85 percent before
fermentation.
Small quantities of tartaric acid should be added to the must if
the acid level is lower than 0.65 percent.
Acid crystals should be dissolved in a small amount of water
before the acid is added to the must. Stir the must well, and
then remeasure the acid content.
Only small amounts of acid should be added at a time.
Sugar Corrections
Ordinary white table sugar can be used for sugar additions.
Low sugar is not a problem in California.
If the sugar content is too low, the grapes are not mature.
High quality table wines cannot be made from immature grapes.
Grapes lacking sugar should be harvested later in the season when
the fruit is fully ripe.
Yeast Nutrients
Yeast requires nitrogen, vitamins and several other materials
to reproduce new yeast cells and ferment the grape sugars.
Grapes deficient in these materials can be difficult to ferment
unless extra nutrients are added to help the yeast.
Chardonnay juice deficient in nitrogen occurs regularly, so
winemakers often add extra nitrogen to all Chardonnay juice.
Directions for yeast nutrients should be followed carefully to
avoid off-flavors in the wine.
Settling White Juice
Fresher white table wines are produced when bits of skin, pulp
and other debris is removed from juice before fermentation.
When the solids have been removed, fermentations are cleaner and
better controlled.
Juice is often settled over night and then the clear juice is
racked off the sediment the next day.
The juice must be kept cold, and the proper amount of sulfur
dioxide should be used.
Sometimes, additional clear juice can be obtained by resettling
the residue.
FERMENTATION
Grape skins have a waxy coating, and the coating is covered
with native yeasts.
Native yeast can spontaneously ferment grapes (without the
winemaker adding additional yeast). Sulfur dioxide is used to
arrest yeast activity, but reasonable quantities of SO2 will not
kill the native yeast.
Most winemakers prefer to add pure cultured yeast to start
fermentation.
Cultured Yeast
Most home winemakers prefer dry yeast because using it is
easier.
Some yeasts like Epernay does not tolerate high levels of
alcohol.
Steinberg yeast does not tolerate high levels of sulfur dioxide.
Montrachet yeast produces more hydrogen sulfide (rotten egg
smell) than many other yeasts. Montrachet yeast should never be
used with grapes containing residual sulfur dust.
Pasteur Champagne yeast can produce large amounts of foam in warm
fermentation.
Small wineries often use dry Prise de Mousse yeast to ferment all
of their wines.
The type of yeast used has little impact on the flavor of aged
wine.
Dry Yeast Rehydration
Yeast manufacturers recommend rehydrating dry yeast.
Dry yeast is rehydrated by adding a small amount of warm water.
About a cup of water should be used for each teaspoon of yeast.
The water temperature should be between 95 and 100 degrees.
After stirring, the yeast mixture should stand for 30 minutes.
Most winemakers use about one gram of dry yeast for each gallon
of must or juice.
White Fermentations
Fermentation temperature is one of the most important factors
for producing quality white table wines.
Light, fruity white wines like Riesling are always fermented at
temperatures ranging from 40 to 55 degrees.
At these low temperatures, white fermentations often continue for
two or three weeks.
Heavier style white wines are often fermented at temperatures
between 55 and 65 degrees.
White juice should always be settled over night.
Only the clarified juice is fermented.
White wines are always fermented in closed containers sealed with
a fermentation trap.
All fermentations should be monitored by measuring the Brix each
day.
When fermentation is complete, the new wine should be racked into
a clean container, and 50 milligrams per liter of SO2 should be
added.
Red Fermentations
Red grapes have colorless juice.
The color is in the grape skins.
Red wine is made by fermenting the juice, pulp, seeds and skins
together for several days.
Lengthy skin contact does not increase color, but it does
increase wine astringency.
Short skin contact time produces softer, more fruity red wines.
Skin contact time is always a compromise, and winemaking
experience is needed.
Usually, four to seven days is adequate for red fermentations.
"When in doubt, press early" is a good rule to follow.
A cap of skins will begin to float after fermentation starts.
If the cap becomes dry, vinegar bacteria can grow and convert the
alcohol into vinegar.
To prevent this acetification problem, the cap should be broken
up periodically and kept wet. Caps on small fermentations will
not be very thick, and small caps can be managed by stirring the
fermentation twice a day.
On larger fermentations, a special tool is needed to punch the
cap down into the juice.
Caps should be punched down twice a day.
More punching down will do no harm, and it may improve the color
of the wine.
Pressing Red Must
Red musts are usually pressed in a basket press, and the
procedure is the same as pressing white juices (see above).
Red fermentations can by pressed by hand, and the wine yield will
be reasonable if the grapes were well crushed.
The following procedure works well.
(1) Cut a piece of 3/4-inch thick plywood to fit inside a plastic
milk crate.
(2) Let the cap rise, and then the liquid can be carefully
syphoned off.
(3) The plastic milk crate is placed on a suitable container, and
a piece of plastic window screen is placed in the bottom of the
crate.
(4) Fill the crate half full of pomace, and place the plywood on
top.
(5) Press by hand, and then place a heavy weight on the plywood.
(6) Let the crate drain for 15 or 20 minutes, and then stir the
pomace and repeat.
After pressing, red wine should be placed in a closed container,
and the container should be sealed with a fermentation lock.
When fermentation is complete, the new wine should be racked off
the gross lees and 50 milligrams per liter of sulfur dioxide
added.
CELLAR OPERATIONS
Cellar operations include wine clarification, stabilization, bulk aging, bottling and bottle aging.
Clarification
Clarification is accomplished by racking, fining and
filtration.
Most white and blush wines will need to be clarified by fining
with Sparkolloid.
Most red wines become clear automatically.
Red wines are often fined with protein materials such as a
gelatin, casein or egg-whites to reduce astringency.
Unflavored "Knox" gelatin, purchased at a grocery
store, can be used to remove excess astringency in red wines.
One level teaspoon of dry gelatin powder for each 5-gallons of
wine is an average dose.
The powder should be mixed in 1 1/2 cups of warm water.
The warm gelatin liquid should be added slowly while constantly
stirring the wine.
After a week or so, the wine should be racked off the fining
lees.
A light gelatin fining can be effective in reducing the amount of
bottle deposit.
Stabilization
Stable wines remain clear after they are bottled.
Unstable wines often change color, produce hazes or throw ugly
sediments after they are bottled. Wine is made stable by fining,
racking, chilling, adding sulfur dioxide and aging.
White and blush wines should be hot stabilized with bentonite.
Two grams of dry bentonite per gallon of wine are often used, but
testing should be done.
The wine should be racked a week or so after adding the
bentonite.
All white and blush wines should be cold stabilized by chilling
the wine to about 28 degrees. Excess tartrate crystals
precipitate when wine is chilled.
Some wineries do both stabilization treatments at once by adding
bentonite and then chilling the wine.
After a week or two, the cold wine is filtered or racked off the
bentonite lees.
White wines are normally racked two or three times before
bottling (excessive racking may oxidize the wine).
Red wines should be racked about every month for the first three
months, then twice a year. During storage, the free sulfur
dioxide content of the wine should be maintained at 25 to 30
milligrams per liter.
Bulk Aging Wine
Aging is a natural process, and no way has been found to speed
up the process.
Small amounts of oxygen are always present when wine is aged in
the cask.
Aging in the bottle, takes place in an absence of oxygen.
Light white wines and blush wines are usually bottled a few
months after harvest.
Chardonnay and Sauvignon Blanc are often bottled after six to 12
months.
Most quality red wines are bottled after one to three years of
barrel aging.
Containers must be kept full, and the sulfur dioxide in the wine
maintained at 20 to 30 milligrams per liter during bulk aging.
Oak
Oak wood can impart desirable flavors to wine.
Oak flavors are best got by storing wine in oak barrels for
extended periods.
Barrels are expensive, and after barrels are four or five years
old, they no longer produce the desirable flavors.
Oak chips can also produce oak flavors in wine.
The quantity of oak chips needed depends upon the style of the
wine and personal preferences. One to two ounces of chips for
5-gallons of wine is a good starting quantity.
The wine should be tasted every few weeks after the chips are
added, and the wine should be racked off the chips when the taste
is satisfactory.
More chips can always be added, but removing excess oak flavor
from wine is difficult.
Most aromatic wines (Riesling, Muscat, etc.) do not benefit from
oak aging.
BOTTLING
Wine must be brilliantly clear and stable before bottling.
Bottling is a simple operation, but several points should be
considered before the bottles are filled.
Adjustments Before Bottling
Any blending should be done many weeks before bottling time so
the winemaker can be sure the new blend is stable.
Wine can become unstable when large additions of tartaric acid
are made and additional cold stabilization may be required.
Usually, small amounts of citric acid can be added to white wines
without upsetting cold stability (to improve acid balance).
Cold stability should be checked before bottling white or blush
wines by placing a wine sample in the refrigerator for 48 hours.
Hot stability should be checked by holding a sample of the wine
at 120 degrees for 48 hours.
The free sulfur dioxide content of the wine should be tested and
adjusted to about 30 milligrams per liter a day or two before
bottling.
Wines bottled with less than 30 milligrams per liter of sulfur
dioxide will be short lived.
Bottle Filling
Clean bottles should be rinsed with very hot water just before
filling.
Rinse each bottle with the sulfite solution made by mixing 1/4
teaspoon of sulfite crystals and 1/2 teaspoon of citric acid with
750 ml of water.
This sulfite solution is strong enough to kill bacteria and
yeast, but the bottles must be drained carefully.
A bottle filler of some kind should always be used to reduce wine
oxidation.
Bottles should be filled from the bottom and with a minimum
amount of foam and splashing. Bottles should be filled until no
more than 1/4 inch exists between the top of the wine and the
bottom of the cork.
Corking
Driving dry corks is preferred.
However, some small hand corkers cannot compress dry corks
adequately and presoaked corks must be used.
Presoak corks in cold water for an hour or so to soften them.
A pinch of sulfite added to the water may help sterilize the
corks.
Drive corks flush, or slightly below the lip of the bottle.
Remove spilled wine from the bottles, or the wine residue will
become moldy.
Labeling
All bottles should have some kind of label to identify the
contents.
Attractive wine labels can be made with a home computer.
Common white glue is often used for attaching wine labels.
A few labels can be applied quickly with a "glue
stick."
Capsules and labels can be applied when the bottles are clean and
dry.
Bottle Aging
Bottles should stand upright for a week or two after corking.
After the pressure has equalized, the bottles can be stored on
their sides (or upside down) in a cool, quiet place.
Red wines are usually aged in the bottle for one or more years to
allow the wine to develop a "bottle bouquet."
Heavier style white wines also benefit from bottle aging.
SUMMARY
High quality wine can only be made when high quality fruit is
picked in optimum condition.
Sulfur dioxide should be added to the grapes as they are crushed.
Juice acidity should be adjusted to 0.65 to 0.85 percent before
fermentation is started.
Attempts to make light, fruity white table wines will usually
fail unless the fermentation temperature can be kept below 60
degrees.
White juice should be settled over night.
In the morning, the liquid is racked off the solids and the
clarified juice is fermented.
Red wine is made by fermenting the juice, pulp, seeds and skins
together.
Caps on red fermentations should be punched down at least twice a
day.
Four to seven days of fermentation time will be adequate for most
red grape varieties.
About 50 milligrams per liter of SO2 should be added when
fermentation is complete.
Wine is made stable by fining, racking and chilling.
White and blush wines require both hot and cold stabilization
treatments.
All wine must be brilliantly clear and stable before bottling.
The free SO2 level should be raised to about 30 milligrams per
liter a day or two before the wine is bottled.
A bottle filler should be used, and the bottles should be filled
from the bottom to reduce wine oxidation.