Quick Facts...
- Select disease-free, preferably vine-ripened, firm
tomatoes for canning. Avoid overripe tomatoes.
- To ensure safe acidity in whole, crushed or juiced
tomatoes, add 2 tablespoons of bottled lemon juice or 1/2
teaspoon of citric acid per quart of tomatoes. For pints,
add 1 tablespoon bottled lemon juice or 1/4 teaspoon citric
acid.
- Freezing is a safe, easy alternative to home canning.
Frozen tomatoes and tomato products do not need added acid.
Tomatoes are the most widely home-canned product in the United
States. They also are one of the most commonly spoiled
home-canned products. The canning processes recommended in
this fact sheet are the result of USDA research on safe
home-canning procedures for tomatoes and tomato products.
Although tomatoes are considered a high-acid food (pH below
4.6), certain conditions and varieties can produce tomatoes
and tomato products with pH values above 4.6. When this
happens, the product must be canned in a pressure canner as a
low-acid product or acidified to a pH of 4.6 or lower with
lemon juice or citric acid.
Research has found several conditions that can reduce the
acidity of tomatoes. These include decay or damage caused by
bruises, cracks, blossom end rot or Insects, and
over-ripening. Tomatoes grown in the shade, ripened in shorter
hours of daylight, or ripened off the vine tend to be lower in
acidity than those ripened in direct sunlight on the vine.
Also, tomatoes attached to dead vines at harvest are
considerably less acidic than tomatoes harvested from healthy
vines. Decayed and damaged tomatoes and those harvested from
frost-killed or dead vines should not be home
canned.
To ensure safe acidity in whole, crushed or juiced tomatoes,
add lemon juice or citric acid when processing in a boiling
water bath. Add 2 tablespoons of bottled lemon juice or 1/2
teaspoon of citric acid per quart of tomatoes. For pints, use
1 tablespoon bottled lemon juice or 1/4 teaspoon citric acid.
Acid can be added directly to the jars before filling with
product. Add sugar to offset the taste, if desired. Four
tablespoons of a 5 percent acidity vinegar per quart can be
used instead of lemon juice or citric acid. However, vinegar
may cause undesirable flavor changes.
The most common reasons for spoilage in home-canned tomato
products are under processing and incomplete seals. Tomatoes
that have not been processed long enough to destroy molds and
heat-resistant bacteria may spoil during storage. One of the
common spoilage organisms, Bacillus coagulans, is
very heat resistant and causes flat-sour spoilage. The jar lid
may still be sealed and the product may appear normal, but the
tomatoes will smell sour because of lactic acid produced by
the growth of B. coagulans in the product. Never use
tomatoes or tomato juices with off-odors.
Molds can grow on the surface of improperly processed tomato
products and may eventually reduce the acidity to a point
where botulism-producing spores can grow and produce a deadly
toxin. Because even minute amounts of botulism toxin can cause
fatal illness, discard without tasting any canned products
that show mold growth on the surface. Discard them where they
cannot be eaten by other people or animals.
The processing times in this fact sheet are designed to ensure
sufficient destruction of bacteria and molds. Where
appropriate, processing recommendations for both water bath
and pressure canning are given. In general, a pressure canner
results in higher quality and more nutritious canned tomato
products.
One bushel of fresh tomatoes weighs 53 pounds and yields
approximately 18 quarts of canned tomatoes or 15 to 18 quarts
of juice. Approximately 2 1/2 to 3 1/2 pounds of fresh
tomatoes makes 1 quart of canned tomatoes.
Standard mason jars are recommended for home canning. Be sure
all jars and closures are perfect. Discard any with cracks,
chips, dents or rust. Defects prevent airtight seals.
Wash jars in hot, soapy water and rinse well before using.
Prepare metal lids as manufacturer directs.
Select fresh, firm, ripe tomatoes. Do not can
soft, overripe, moldy or decayed tomatoes or tomatoes
harvested from dead or frost-killed vines. Green tomatoes are
more acidic than ripened tomatoes and can be canned safely
with any of the following recommendations.
Wash tomatoes well and drain. Dip in boiling water for 30 to
60 seconds or until the skins split. Then dip in cold water.
Use a sharp knife to cut out the stem and all of the white
core beneath the stem. Peel off the skin. Trim off any bruised
or discolored portions.
After jars are filled with food, remove trapped air bubbles,
adjust the headspace, and clean the jar tops before
processing. To remove trapped air bubbles, insert a
nonmetallic spatula or knife between the food and the jar.
Slowly turn the jar and move the spatula up and down to allow
air bubbles to escape. Add more liquid if necessary to obtain
the proper headspace (see recipes in Table 1). Wipe the jar
rim with a clean, damp paper towel to remove any food
particles. Place pretreated lid on the jar. Turn the screw
band fingertip tight.
The jars are now ready to process in a boiling water bath or
pressure canner.
After processing, carefully remove jars from canner and place
on rack, dry towel or newspaper. Allow jars to cool untouched,
away from drafts, for 12 to 24 hours before testing seals. To
test jar seals, press flat metal lids at the center of lid. It
should be slightly concave and not move. Remove screw bands.
Label sealed jars with contents, canning method and date.
Store in a clean, cool, dry, dark place.
Jars of tomatoes or tomato products that do not seal can be
safely reprocessed within 24 hours of the initial processing.
However, if the jar sealed at first and then unsealed a few
days later, spoilage is indicated. Do not reprocess such jars;
destroy the contents.
To reprocess, remove lids and empty the food and liquid into a
pan. Heat to boiling and pack into clean, hot jars. Put on new
pretreated lids. Process again for the full time.
The quality of twice-processed foods may be lower, with
textural changes and additional loss of heat-sensitive
nutrients such as vitamin C and B-complex.
Reference
The Complete Guide to Home Canning. Agriculture
Information Bulletin No. 539, U.S. Department of Agriculture,
Extension Service. 1994.
|
Table 1: Directions for
canning tomatoes and tomato products in a boiling water
bath and/or pressure canner.
|
|
General directions:
Wash, skin and trim tomatoes as described in the Prepare
Tomatoes section. Fill jars according to the raw or hot
pack method described for each product. Release air
bubbles and close jars as described in the Close Jars and
Process section. Process in a
boiling water bath or pressure canner as directed for
your altitude. Begin timing when water returns to boiling
or when canner reaches correct pressure.
|
|
Processing Time (in minutes)
Boiling water bath at altitudes of:
|
|
Product and Procedure
|
Jar size
|
1,001
-3,000 ft. |
3,001
-6,000 ft.
|
6,001
-8,000 ft.
|
8,001
-10,000 ft.
|
Pressure
canner*
|
|
Tomato
Juice |
pints
quarts
|
40
45
|
45
50 |
50
55
|
55
60
|
15
15 |
|
Wash and trim tomatoes. To prevent
juice from separating, quickly quarter 1 pound of tomatoes
into a large saucepan. Heat immediately to boiling while
crushing. Continue to slowly add freshly cut tomato
quarters to the boiling mixture and crush. Simmer 5
minutes after all pieces are added. Press juice through a
foodmill or sieve to remove skins and seeds. Add 2
tablespoons bottled lemon juice or 1/2 teaspoon citric
acid to quart jars. Use half this amount for pints. Add 1
teaspoon salt per quart to jars, if desired. Heat juice
again to boiling. Fill jars with hot juice, leaving
1/2-inch headspace. Close jars and process.
|
|
Tomato and
Vegetable Juice Blend
|
pints
quarts
|
40
45
|
45
50
|
50
55
|
55
60
|
15
15
|
|
Crush and simmer tomatoes as for
making tomato juice (above). Add no more than 3 cups of
any combination of finely chopped celery, onions, carrots
and peppers for each 22 pounds of tomatoes used. Simmer
mixture 20 minutes. Press mixture through a foodmill or
sieve and continue as described above. Be sure to add
lemon juice or citric acid. |
|
Crushed
Tomatoes
(with no added liquid)
|
pints
quarts |
40
50
|
45
55
|
50
60
|
55
65
|
15
15
|
|
Prepare and quarter tomatoes. Bring
1/6 of quarters quickly to a boil in a large pot, crushing
and stirring to exude the juice. Gradually add remaining
quarters, stirring constantly. Boil gently 5 minutes. Add
2 tablespoons bottled lemon juice or 1/2 teaspoon citric
acid to quart jars. Use half this amount for pints. Add 1
teaspoon salt per quart to jars, if desired. Fill jars
immediately with hot tomatoes, leaving 1/2-inch headspace.
Close jars and process.
|
|
Standard Tomato Sauce
|
pints
quarts
|
40
45
|
45
50
|
50
55
|
55
60
|
15
15
|
|
Prepare and press tomatoes as for
making tomato juice. Simmer in large kettle until sauce
reaches desired consistency (volume is reduced by
one-third for thin sauce or by one-half for thick sauce).
Add 2 tablespoons bottled lemon juice or 1/2 teaspoon
citric acid to quart jars. Use half this amount for pints.
Add 1 teaspoon salt per quart to jars, if desired. Fill
jars with hot sauce, leaving 1/4-inch headspace. Close
jars and process.
|
|
Whole
or Halved Tomatoes
(packed in water)
|
pints
quarts
|
45
50 |
50
55
|
55
60 |
60
65
|
15
15
|
|
Wash and peel tomatoes. Leave whole
or cut in half. Add 2 tablespoons bottled lemon juice or
1/2 teaspoon citric acid to quart jars. Use half this
amount for pints. Add 1 teaspoon salt per quart to jars,
if desired. Hot Pack -- Place tomatoes in
large saucepan and add enough water to cover. Boil gently
for 5 minutes. Fill jars with hot tomatoes and cooking
liquid, leaving 1/2-inch headspace. Close jars and
process. Raw Pack -- Fill prepared jars
with raw tomatoes to 1/2 inch of jar tops. Add hot water,
adjusting headspace to 1/2 inch. Close jars and process.
Processing time is the same for hot and raw pack.
|
|
Whole or Halved Tomatoes
(packed in tomato juice or without added liquid)
|
pints
quarts
|
90
90
|
95
95
|
100
100
|
105
105
|
25
25
|
|
Wash and peel tomatoes; leave whole
or cut in half. Add 2 tablespoons bottled lemon juice or
1/2 teaspoon citric acid to quart jars. Use half this
amount for pints. Add 1 teaspoon salt per quart to jars,
if desired. Hot Pack -- Place tomatoes in
large saucepan; add enough tomato juice to cover. Boil
gently 5 minutes. Fill jars with hot tomatoes to 1/2 inch
of jar tops. Cover tomatoes with hot tomato juice, leaving
1/2-inch headspace. Raw Pack -- Fill jars
with raw tomatoes to 1/2 inch of jar tops. Cover tomatoes
with hot tomato juice or press tomatoes in jars until
spaces fill with juice. Leave 1/2-inch headspace. Close
jars and process all pack styles for the length of time
specified above.
|
|
Tomatoes with
Zucchini or Okra
|
pints
quarts |
not recommended
|
30
35
|
|
Use up to 1 pound of zucchini or okra
for every 3 pounds of tomatoes. Wash, peel and quarter
tomatoes. Wash vegetables and slice or cube. Bring
tomatoes to a boil and simmer 10 minutes. Add vegetables
and boil gently 5 minutes. Add 1 teaspoon of salt per
quart to jars, if desired. Fill jars with mixture. Leave
1-inch headspace. Close jars and process. For variation,
add 4 or 5 pearl onions or 2 onion slices to each jar.
|
|
Spaghetti Sauce
(with meat) |
pints
quarts
|
not recommended
|
60
70
|
|
30 lbs tomatoes, peeled, quartered
2 1/2 lbs ground beef or sausage
(recipe with meat)
1 cup onions, chopped
5 cloves garlic, minced
1 cup celery or green pepper, chopped
1 lb fresh mushrooms, sliced
4 1/2 teaspoons salt
2 tablespoons oregano
4 tablespoons parsley, minced
2 teaspoons black pepper
1/4 cup brown sugar
1/4 cup vegetable oil
(recipe without meat) |
With meat -- Prepare
tomatoes and boil 20 minutes, uncovered, in large
saucepan. Put through a food mill or sieve. Sauté meat
until brown. Add onions, garlic, celery, green peppers and
mushrooms (if desired). Cook until vegetables are tender.
Combine with tomato pulp in large saucepan. Add salt,
oregano, parsley, pepper and brown sugar. Bring to a boil.
Simmer, uncovered, until initial volume is reduced by
nearly one-half. Stir frequently to avoid burning. Fill
jars, leaving 1-inch headspace. Close jars and process for
times above. Yields 10 pints.
|
|
|
pints
quarts
|
not recommended
|
20
25
|
|
|
Without meat --
Follow the above directions, omit the meat and saute the
vegetables in 1/4 cup vegetable oil until tender. Yields 9
pints.
Caution! Do not increase the portions of
onions, peppers or mushrooms.
|
|
Mexican Tomato Sauce
|
pints
quarts
|
not recommended
|
20
25
|
|
2 1/2 to 3 lbs chili peppers, peeled
and chopped
18 lbs tomatoes, peeled, chopped
3 cups onions, chopped
1 tablespoon salt
1 tablespoon oregano
1/2 cup vinegar
|
Wash and dry chilies. Make a small
slit in side of pepper for steam to escape. Place in a hot
oven or broiler (400 degrees) for 6-8 minutes, turning
frequently until skins blister and crack. Place in a pan
and cover with a damp cloth for several minutes to cool.
Peel off skin starting at stem end and peeling downward.
Discard seeds and chop peppers. Wash, peel and coarsely
chop tomatoes. Combine with chopped peppers and remaining
ingredients in large saucepan. Bring to a boil, cover and
simmer 10 minutes. Fill jars, leaving 1-inch headspace.
Close jars and process. Yields about 7 quarts.
Caution! Wear rubber gloves while handling chilies
or wash hands thoroughly with soap and water before
touching your face.
|
|
Tomato Ketchup
|
pints and
half pints |
20
|
20
|
25
|
25
|
|
24 lbs ripe tomatoes, peeled,
quartered
3 cups onions, chopped
3/4 teaspoon ground red pepper
4 teaspoons whole cloves
3 sticks cinnamon, crushed
1 1/2 teaspoons whole allspice
3 tablespoons celery seeds
3 cups cider vinegar (5%)
1 1/2 cups sugar
1/4 cup salt |
Wash, peel and quarter tomatoes.
Combine with chopped onions and red pepper in a 4-gallon
stockpot or large kettle. Bring to a boil and simmer 20
minutes. Meanwhile, combine spices in a spice bag. Place
with vinegar in a 2-quart saucepan. Bring to a boil and
turn off heat. Let stand 20 minutes. Remove spice bag and
combine vinegar and tomato mixture. Boil mixture 30
minutes. Press boiled mixture through a food mill or
sieve. Return to pot. Add sugar and salt. Boil gently,
stirring frequently, until volume is reduced by one-half
or mixture rounds up on a spoon without separation. Fill
jars, leaving 1/4-inch headspace. Close jars and process.
Yields 6 to 7 pints.
|
|
Chili
Salsa
(hot tomato-pepper sauce)
|
pints and
half pints
|
20
|
20
|
25
|
25
|
|
5 lbs tomatoes, peeled, chopped
2 lbs chili peppers, peeled, chopped
1 lb onions, chopped
1 cup vinegar (5%)
3 teaspoons salt
1/2 teaspoon pepper |
Combine prepared tomatoes, peppers,
onions, vinegar, salt and pepper in a large saucepan. (See
Mexican tomato sauce for information on peeling chili
peppers.) Heat to a boil and simmer 10 minutes. Fill jars,
leaving 1/2-inch headspace. Close jars and process. Yields
6 to 8 pints.
Caution! Wear rubber gloves while handling chilies
or wash hands thoroughly with soap and water before
touching your face.
|
|
*Pressure canner -- dial gauge:
10 lb + 1/2 lb/1,000 ft.; weighted gauge: 15 lb at
1,000-10,000 ft.
|
Reference
The Complete Guide to
Home Canning. Home and Garden Bulletin, U.S. Department
of Agriculture, 1994. |
