Home Preservation of Florida Grapes
Taken from the brochure
"Home Preservation of Florida Grapes"
D.M. Gursky and R.P. Bates
University of Florida
Grapes have returned to Florida and are definitely here to stay. In the
1920's, several thousand acres of grapes had become established in central
Florida when a ruinous disease destroyed the plantings, delivering the devastating
message that grapes do not grow in Florida. This fact was essentially true
for the traditional grape types (Vitis vinifera and Vitis labrusca) of Europe,
California, and the northeastern United States. Fortunately, the traditional
muscadine grape of the Southland - Vitis rotundifolia, often known as "Scuppernong"
- is relatively resistant to disease. The breeding efforts at the Institute
of Food and Agricultural Sciences, Agricultural Research Center, Leesburg,
and in other southern states, have resulted in a number of bunch and muscadine
grape varieties that are well-suited to Florida. (See Fruit Crops Fact Sheets,
"The Muscadine Grape," and "The Bunch Grape.") These varieties are a big
improvernent over the older plantings in cultivation characteristics and
eating quality. If you have the yard space and the inclination, you are
invited to try your hand at growing these varieties - from several vines
to a modest vineyard. Many Floridians are doing just that as the increasing
membership in the Florida Grape Growers Association (FGGA) testifies. If
you would rather leave the growing to others, there are a number of pick-your-own
operations which offer an abundant supply and varied source of grapes. While
introducing you to Florida grapes, these also will provide you with ample
raw material for processed grape products. If the present efforts of the
FGGA are successful, you will soon be able to purchase these grapes in local
food stores. Because of the number of Florida grape types, it is necessary
to distinguish the main types from each other. Fortunately, they complement
each other in eating quality and ripening season. Bunch grapes generally
are smaller than muscadines and grow in clusters, resembling the grapes
with which most consumers are familiar. Muscadines, native to Florida, have
smaller leaves and the fruit is borne singly or in small clusters. They
range in color from deep-blue (black) to bronze. Properly prepared muscadine
juice has a refreshing taste and an aroma equaled by few other fruit juices.
The home canner will find other products prepared from muscadines, such
as sauces, jams and jellies, are deliciously different, too.
Since the bunch type ripens about a month earlier than muscadines in Florida,
the total grape season runs from late June through September. Muscadines
mature in late August through September while bunch grapes are harvested
from early July through August. Food quality grapes should appear fresh,
ripe and plump. Grape flavor is a combination of sweetness, tartness, aroma,
and astringency. As the fruit matures, sweetness and color increase while
sourness decreases. A warm, sunny season will give grapes higher sugar and
lower astringency than a cool, cloudy season. The fruit of some grape varieties
have berries that drop before harvest. Of this type, some may have a moist
stem scar which favors spoilage. Spoilage will be reduced by selecting varieties
that do not shatter from the stem. The majority of muscadines have tougher
skins or hulls than bunch grapes and withstand jarring or dropping. Grapes
that ripen evenly are usually harvested by shaking the vines and allowing
the fruit to fall into canvass or burlap sacks spread under the vine. If
the muscadines are for shipping or if bunch grapes are being harvested,
hand-picking is the preferred method since the fruit must stay in good condition
many days after harvest.
After harvest, grapes deteriorate in flavor and aroma relatively rapidly
and should be consumed or processed as soon as possible. Grapes can be stored
up to a week if you place them as soon as possible in a cold refrigerator.
The longer they are held, the greater the flavor loss and the lower the
quality of the finished product. Wilting of stem and berries is slowed in
a high humidity environment but, in time, even refrigeration supports growth
of yeast and molds, so make your grape preservation plans ahead of the harvest.
Sanitation is an important factor in preparing high quality, uncontaminated
grape products. The fruit should be carefully washed and the processing
equipment and work area thoroughly cleaned.
Stems and seeds usually are removed depending on the specific recipe. Although
deseeding is best, it is a slow job, accomplished by cutting the grapes
in half and picking out the seeds. An alternate method when a large volume
of grapes is to be used in a recipe requiring pulp and/or hulls, is to push
the grapes through a sieve. However, this method may be unsatisfactory with
unripe fruit or varieties with hard-to-remove seeds. If so, the pulp may
be boiled for five minutes and then pushed through the sieve.
If this is your first canning experience, information available from your
county extension office can help you. The canning books listed at the end
of this publication also are excellent references and list necessary equipment
such as long-handled spoons, measuring utensils, cheesecloth, thermometer
and timer. Home-canning of less than five gallons of juice is easily done
using the boiling water bath method. This method is recommended for canning
grapes and all other acid foods which can be safely processed at boiling
temperature, see Food Science Fact Sheet, "Safety in Home Canning". Boiling
water bath canners are available commercially, but any kettle large enough
for the canning jars to be covered by one to two inches of boiling water
will do. The canner should have a lid so that a rolling boil may be maintained
throughout processing. The canning jars must be held off the bottom for
proper heat penetration and they must be divided to prevent bumping and
cracking during boiling. A metal basket fitting into the kettle will keep
the jars off the bottom and separate them from each other. Use only standard-type
canning jars with the manufacturer's imprinted name. Do not use commercial
jars in which one would buy peanut butter, mayonnaise, instant coffee, baby
food or the like. Most of these jars are designed for a single use only
and are made of thin glass for high-speed packaging machines. Choose a jar
size that fits in well with your meal planning: pint and quart-size jars
are most popular. Wide mouth jars are best for packing whole grapes or canning
jellies, jams, sauces and marmalades. Narrow-mouth jars should be used for
canning grape juice. Check canning jars for defects and discard any chipped
or cracked jars. A two-piece-self-seal lid (with a metal disk and a metal
ring) is advantageous because it seals itself as the jar cools and indicates
a proper seal by its concave surface. The ring should not be tightened after
processing and during cooling, or the seal may break.
Muscadine juice is a pleasant beverage with dark grapes giving a deep, red
juice and bronze grapes producing a pale, gold juice.
Crushing and Pressing
Crushing the fruit is the first step in preparing grape juice. A potato
masher or other blunt instrument can be used to smash the grapes until a
small amount of juice collects in the crushing vessel. Mechanical crushers
are sometimes included as a feature on fruit presses. Many methods of pressing
grapes are possible, depending on the type of equipment available. Crushers,
Rack and Frame or Basket presses are efficient tools for those who produce
large volumes of juice. They are available at wine equipment supply stores.
A type of Rack and Frame press can be built with the instructions contained
in Special Report No.8 issued by the New York State Agricultural Experiment
Station, Geneva. N.Y. (July 1972). When you lack a press and are pressing
small quantities of grapes, the simplest, manual pressing method is to place
the crushed grapes in strong sack cloth of medium mesh and twist the ends
in opposite directions with a stick. An alternate procedure is to place
the grapes in a medium-meshed cloth and mash them with a heavy, blunt instrument.
Have ready a container large enough to catch the juice as it flows from
the cloth. You can increase and make juice extraction easier by warming
the grapes to 140oF, while stirring, before pressing.
Treating Juice Supersaturated with Tartrates
In the presence of the mineral, potassium, naturally-occurring tartaric
acid forms bitartrates which will settle out as crystals when the freshly
pressed juice is stored. To prevent these crystals in the final product,
allow the pressed juice to stand at the coldest possible refrigerator temperature
(near 32oF) for two to three days. Some of the tartaric acid
as tartrate crystals, which provides acid taste, will settle out along with
other impurities. Adjustments in flavor of the juice also are made at this
point: the longer the freshly pressed juice is refrigerated, the less tart
it becomes and the sweeter it will taste. Storage in the refrigerator for
longer than three days may yield a slightly fermented juice caused by inherent
wild yeasts. Tartrate crystals will be seen as tiny, gold-brown particles
on the sides and bottom of the juice container and should not be disturbed.
Carefully pour the clear juice off its sediment into a clean container.
Sugar may be added to taste. Stir the juice thoroughly to dissolve the sugar.
Before hot juice is poured into canning jars, they must be tempered. This
is done by pouring boiling water inside and out or by running the jars through
an automatic dishwasher with a very hot rinse cycle. Heat the pressed and
de-tartrated juice to simmering (185-205oF), stirring constantly.
Pour the juice into the clean, hot jars, leaving approximately 1/4 inch
of headspace. Tighten lids and use tongs to immediately lower jars into
a bath of simmering (NOT boiling) water. The duration of this heat treatment
should be 5 minutes for pint jars and 10 minutes for quart jars. Heating
too long will give a cooked off-flavor juice and heating too short a time
will not kill organisms associated with spoilage. After heat processing,
promptly remove the jars from the canner, invert and place on cloths or
wire racks to cool. The jars should be kept a few inches apart to aid cooling
and out of drafts to prevent breakage. Remove the metal ring when juice
is entirely cool. If the ring sticks, cover with a hot, damp cloth for a
minute or two to loosen. Test the seal by tipping the jar slightly and observing
for leakage or bubbles rising from the lid.
Canning Whole Grapes
Whole grapes for canning should be firm. washed and free of seeds. Pack
into jars, cover with medium-heavy syrup or juice(Five and one-half cups
of medium-heavy syrup is prepared by dissolving three cups sugar in four
cups water. In the interest of reducing calories you may wish to use a lighter
syrup or grape juice.) and shake down. Exhaust the container by placing
it in boiling water for 30 minutes, adding syrup if necessary. Seal the
jars and heat-process pint jars for 10 minutes and quarts for 12 minutes
in a boiling water bath at 212oF.
Grape sauces are a delicious and colorful topping on cheesecake, ice cream
or whatever your imagination and taste buds allow. Wash the fruit and separate
skin and pulp. Cook the hulls until tender with one cup water to three cups
hulls. Heat the pulp and push through a sieve to remove seeds. Combine hulls
and pulp and add one cup sugar to six cups pulp. Bring to a boil and cook
for five minutes. Pack into clean, hot jars and seal. Process pint jars
for 5 minutes and quart jars for 8 minutes in a boiling water bath at 212oF.
If fresh grapes are to be frozen for later use, they should be washed and
the stems removed. Fill a container with fruit and pour in medium-heavy
syrup* to cover, leaving enough headspace for expansion. Press the grapes
down under the syrup and hold in place with a crumpled piece of waxed paper,
foil or saran film. Close and seal container while in the refrigerator,
at room temperature or in a pan of cold water. The fruit should be served
immediately after thawing while a few ice crystals still remain.
Good detailed cookbooks or equipment manufacturer's booklets may discuss
grape products, although it's unlikely that Muscadines will be mentioned;
several good ones are:
Putting Food By,
The Stephen Greene Press,
Brattleboro, VT 05301.
Better Homes and
Gardens New Cook Book,
Better Homes and Gardens,
Brooks, NY, N.Y.
Ball Blue Book,
345 S. High Street,
Muncie, IN 47302.
Kerr Home Canning Book,
Kerr Glass Manufacturing Corp.,
Sand Springs, OK 74063.
Home Canning: The Last Word;
Farm Journal, Inc., Philadelphia. PA.
A large number of states with grape industries have published information
on grape production and preservation (Georgia and North Carolina are particularly
active with Muscadines). If you travel or have friends in other states you
may be able to obtain interesting publications from various Cooperative
State Extension Services. The Florida Cooperative Extension Service, University
of Florida, Gainesville, FL 32611 or your County Extension Office can supply
you with the following publications.
The Federal Government, Superintendent of Documents, U.S. Government Printing
Office, Washington, D.C. 20402 has a number of bulletins on home food preservation
appropriate to grape products. These are:
- Home Wine Making in Florida:
- Food Science Fact Sheet FS-3
- Safety in HomeCanning:
- Food Science Fact Sheet FS-6
- The Muscadine Grape:
- Fruit Crops Fact Sheet FC-16
- The Bunch Grape:
- Fruit Crops Fact Sheet FC-17
- Using Florida Fruits & Grapes:
- Extension Home Economics 127
With these sources and your own initiative and imagination you should be
able to add Florida grapes to your list of favorite foods.
- Home Canning of Fruits & Vegetables
- Home & Garden Bulletin No.8
- Home Freezing of Fruits & Vegetables
- Home & Garden Bulletin No.10
- Drying Food at Home
- Home & Garden Bulletin No.217
- How to Make Jams, Jellies and Preserves at Home
- Home & Garden Bulletin No.56
Grape jelly, jams, preserves and butter provide excellent ways to utilize
ripe to unripe grapes and are fun to make. The various spreads differ primarily
in consistency. Most of them contain the four essential ingredients: fruit,
pectin, acid and sugar. The grapes supply the spread with color and flavor.
The best flavored grape spreads are made with a mixture of ripe and slightly
under-ripe grapes. An overly-ripe fruit will give thin, sweet jelly and
commercial pectin must be added. Pectin is a natural component of fruit
and causes the jelly to gel. The presence of pectin varies with the degree
of ripeness - unripe grapes contain more pectin than over-ripe grapes. Many
recipes call for the addition of pectin. Two types are commercially available:
liquid and powdered. The two kinds cannot be used interchangeably, so be
sure to use the type the recipe calls for. Acid enhances flavor and aids
gel formation. Unripe fruit usually contains more acid and will result in
a tart spread. Sugar helps preserve the mixture, contributes to flavor and
helps set the gel. Granulated, white cane or beet sugar may be used.
In making jellies, the fruit is used in a form called "jelly stock," which
is prepared as follows: Wash the grapes, crush them to provide a small amount
of juice in a crushing vessel. Add 1/2 cup water for each six pounds of
fruit and bring slowly to a simmer in a covered kettle. Simmer for 10 minutes.
Remove from the heat and allow to stand for 10 minutes. Meanwhile, line
a large container with two to three layers of damp cheesecloth. Place the
collander over a large bowl, pour the cooled grapes into the collander and
allow the juice to drip out. Too much pressure on the grapes will release
unpleasant flavors from the seeds and hulls of some varieties, so, do not
push the grapes through the collander. Allow the juice to stand refrigerated
overnight, then warm to room temperature and strain it through a flannel
jelly bag. Do not add sugar to the jelly stock and use it according to the
specific recipe being followed. Jelly stock may be canned or frozen for
Making jelly with ripe to unripe fruit:
4 cups jelly stock 3 cups sugar Heat jelly stock to boiling, add sugar and
stir until dissolved. Boil rapidly until temperature reaches 223oF.
This is the "Jelly point." Skim and pour into hot, clean. half-pint jars,
leaving 1/4 inch headspace. Seal with a two-piece-self-seal lid. Invert
hot jar for at least 30 seconds to destroy spoilage microbes on the lid.
Making jelly with very ripe fruit:
4 cups jelly stock (from ripe grapes) 7 cups sugar 1/2 bottle liquid pectin
Measure juice into kettle and stir in sugar. Place on high heat and, stirring
constantly, bring quickly to a full, rolling boil that cannot be stirred
down. Add pectin and heat again to a full, rolling boil. Boil for one minute.
Remove from heat and quickly skim off foam. Pour at once into hot glasses
Jams are made from crushed or ground fruit and have a softer consistency
than jellies. However, the fruit should again be ripe to under-ripe unless
commercial pectin is added. Use the following: 2 quarts stemmed grapes,
6 cups sugar. Separate pulp and skins. Chop skins in a food blender, if
desired, and cook skins gently for 15 to 20 minutes, adding enough water
to prevent sticking to the pan. Cook pulp without water until soft and press
through a collander to remove seeds. Bring pulp, skins and sugar to a boil,
stirring constantly. Cook for about 10 minutes at 220oF until
mixture has thickened somewhat. Pour the boiling hot mixture into hot jars,
leaving 1/4 inch headspace. Seal and process half-pint jars in a boiling
water bath for 15 minutes.
Store jams and jellies in a cool, dry place. The shorter the storage time,
the better the eating quality of the finished product.
As commercial raisins become exorbitantly expensive, consider drying Florida
grapes for a source of raisin-like fruit bits. First of all, be prepared
and patient for deseeding which is advantageous in that it will speed the
drying process by opening the skin. A drying procedure involves prolonged,
mild heat to extract moisture and moving air to carry the released water
away (see U.S.D.A. Bulletin 217). Outdoor drying conditions are ideal with
continued sunshine, high temperatures and low humidity. However, grapes
are among the more difficult fruits to dry and the humid, Florida summers
will not hasten the process. The grapes should be cleaned, deseeded and
spread on wire racks to dry in the sun. If you live near a busy highway
or in a smoggy, airpolluted city, use your oven instead of the sun to dry
the grapes. Keep the oven racks at least six inches away from the heat source
and, when using an elec tric oven. Crack the door open about 2 to 3 inches.
Start the oven at its lowest temperature setting 120o-140oF)
and place a single layer of grapes on a wire rack or cookie sheet. Gradually
increase the oven temperature to 145oF and hold there until nearly
dry. The fruit is dry enough when it feels leathery and moisture cannot
be squeezed from it (raisin-like texture). Since grapes taken directly from
the heat source will seem softer and more pliable than they really are,
cool a test handful a few minutes before deciding they are done. During
the last hour of oven drying, reduce the temperature to 135oF
if there seems to be danger of scorching. In an oven, the total drying time
should be less than eight hours while sun drying may take as long as one
week. Cool and store the finished product in a dry place. The fruit bits
may be added to cookie, cake, quick bread and pie recipes or consumed as
they are. Further research into drying Florida agricultural products will
undoubtably generate information on other drying procedures and add to the
versatility and utility of dried Florida grape products.
The Florida Grape Growers Association, consists of both commercial and backyard
growers. A number are in the pick-your-own or retail business and represent
a good source of Florida grapes and other fruits. Members are active throughout
the state and conduct several meetings annually involving grape field days
in cooperation with IFAS Agricultural Research Centers. Incidently, attendance
at these meetings and visits to nearby vineyards can be a valuable introduction
to Florida grapes.
Your kitchen is the place to get started simply with small quantities of
grapes. As you deal with large amounts the wine hobby section of department
stores, wine hobby shops, available in the Yellow Pages, and mail order
firms, are a good source of grape crushers, presses, strainers, etc.