Reasons Fruit Float in Jars |
 There are several reasons why fruit floats in jars. If the fruit is lighter
than the syrup or if it's too ripe, it will float.Other causes of floating
include processing too long or at too high a temperature, using a heavy syrup,
or packing fruit too loosely. Floating does not affect the flavor or keeping quality of fruit.But there are
ways to prevent it.If fruits are loosely packed into jars, shrinkage during
processing will result in floating.So one way to avoid floating is to pack fruit
solidly into the jar, as closely as possible without crushing.Raw packed berries can be pretreated with sugar to reduce floating.The fruit
absorbs part of the sugar while some of the water in the fruit is released to
form a syrup or juice. You can also prevent or reduce floating by using firm, ripe fruit for
canning, by heating it before packing, and by using light to medium syrups
instead of heavy syrups. After you fill a jar, run a narrow rubber spatula or plastic knife between
the food and the jar to drive out the air bubbles.You may then be able to add
more fruit and syrup.
If you are canning without a sweetener, make sure the fruit is firm but
ripe.If hot-packed fruit is the preferred method, make sure you use the right
time and method for processing the particular fruit you're canning. Here is a summary of ways to prevent fruit from floating in jars: use fresh,
ripe fruit; pack the fruit solidly; avoid heavy syrups; pretreat berries with
sugar; heat fruit before packing and use the correct time and method for
processing. Remember also that floating does not affect the flavor or keeping
quality of fruit.
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Problems with Pickles and
Relishes
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Problems
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Solution
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| What kind of
container should be used for making
pickles? |
Use utensils of unchipped enamelware,
stainless steel, aluminum, or glass
for heating pickling liquids. Do not
use copper, brass, galvanized, or iron
utensils. These metals may react with
acids or salts and cause undesirable
color changes in pickles or form undesirable
compounds. Do not store pickling liquid
in stainless steel or aluminum utensils.
Pitting will occur.Use a crock or stone jar, unchipped
enamel-lined pan, or large glass jar,
bowl, or casserole for fermenting or
brining. Stainless steel containers
are not recommended for brining pickles
because pitting of the container will
occur over time because salt in the
brine is corrosive. |
| Can alterations
in a pickle or relish recipe be made
safely? |
The level of acidity in a pickled
product is as important to its safety
as it is to taste and texture. Do not
alter vinegar, food, or water proportions
in a recipe or use a vinegar with unknown
acidity. Use only recipes with tested
proportions of ingredients. There must
be a minimum, uniform level of acid
throughout the mixed product to prevent
the growth of botulinum bacteria. |
| What causes
pickles to taste bitter? |
There are several possible causes
for bitter-tasting pickles, including
the Growing conditions:
Variety: some varieties are
more bitter than others. Use a variety
specifically for pickling. The short soaking in a salt
brine, called for in many recipes,
will help draw out bitter juices.
The bitter taste is usually
more concentrated at the stem end
of the fruit rather than the blossom
end and in the skin or directly
beneath the skin, not in the fleshy
area around the seeds. Taste a small
portion of the stem end before preparing
cucumbers. If bitterness is present,
it can often be removed by cutting
a larger portion off the stem end
and by peeling more deeply than
usual. Although peeled cucumbers
could not be used to make pickles,
they could be chopped and used to
prepare relishes.
Use of a salt substitute for
pickling could also cause bitterness.
Use only canning or pickling salt.
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| What causes
pickles to be hollow? |
Hollowness in pickles usually
results from poorly developed cucumbers,
keeping cucumbers too long before pickling,
too rapid fermentation, or too strong
or too weak a brine during fermentation. |
| What causes
soft or slippery pickles? |
These generally result from microbial
action, which causes spoilage. Once
a pickle becomes soft, it cannot be
made firm. Microbial activity may be
caused by too little salt or acid, cucumbers
not covered with brine during fermentation,
and scum scattered throughout the brine
during fermentation. Other causes are
insufficient heat treatment, a seal
that is not airtight, and moldy garlic
or spices. Blossoms, if not entirely
removed from the cucumbers before fermentation,
may contain fungi or yeasts responsible
for enzymatic softening of pickles. |
| Why do some
pickles turn dark? |
Use of ground spices, too much
spice, iodized salt, overcooking, use
of iron utensils, and minerals in water,
especially iron, may cause darkness
in pickles. |
| What causes
shriveled pickles? |
Shriveling may result from using
too strong a vinegar, sugar, or salt
solution at the start of the pickling
process. In making very sweet or very
sour pickles, it is best to start with
a diluted solution and increase it gradually
to the desired strength. Overcooking
or overprocessing also causes shriveling. |
| Why should
pickles be processed in a boiling-water_bath
canner? |
Pickle products require heat treatment
to destroy organisms that cause spoilage
and to inactivate enzymes that may affect
flavor, color, and texture. There is
always danger of spoilage organisms
entering the food when it is transferred
from kettle to jar. Adequate heating
is best achieved by processing in a
boiling-water_bath canner. |
| Why does
sauerkraut turn dark? |
Darkness in sauerkraut may be
caused by unwashed and improperly trimmed
cabbage, insufficient juice to cover
fermenting cabbage, uneven distribution
of salt, exposure to air, high temperatures
during fermentation, processing and
storage, and long storage period. |
| What contributes
to an undesirable softness in kraut?
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Softness in kraut may result from
insufficient salt, temperatures too
high during fermentation, uneven distribution
of salt, and air pockets caused by improper
packing. |
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Canning With Sweeteners Other Than Sugar |
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Home-canned fruits do not require sugar to prevent spoilage. The main reason
sugar is used during canning is to help preserve the fruit's texture, flavor,
and color. All or part of the sugar can be replaced by other sweeteners, such as
fruit juices, honey, corn syrup, maple syrup, and non-nutritive sweeteners.
Fruit juice may be substituted for all of the sugar syrup in your recipe or
for part of it, if you prefer. The juice may be purchased or made from fresh
fruit.To make your own juice, use fully ripe, juicy fruit. Crush it in a pan and
bring it to a simmer over low heat for several minutes, stirring gently. Then
strain the hot pulp through a jelly bag or cheesecloth.
Mild-flavored honey and light corn syrup may be used to replace as much as
half of the white sugar called for in your canning syrup recipe. Honey will also
add flavor and color to the fruit, depending on the type of honey you use. Honey
also may darken during storage. It's best to use fresh mild, light colored honey
in canning.
Maple syrup can be used to replace up to 1/4 of the sugar in a recipe, but it
will effect the natural flavor and color of the fruit.
It's best not to use molasses, sorghum, dark corn syrup, or other
strong-flavored syrups when canning fruit. These sweeteners darken the fruit and
over power the fruit flavor.
Non-nutritive sweeteners may be used to sweeten canning syrups, but they may
cause a bitter or metallic aftertaste. You can reduce this problem by adding the
non-nutritive sweetener when you serve the fruit rather than when you process
it.
Most of the sugar substitutes mentioned here will cost more per cup than
granulated sugar, and except for non-nutritive sweeteners and fruit juices, they
will produce a canning syrup higher in calories than a medium syrup made with
granulated sugar. However, some of them, particularly fruit juice, will add
nutritive value to the canning syrup.
Replacing 1/3 of the sugar in a medium-syrup recipe with an equal amount of
honey will add about 30 calories per pint of fruit.
If you have never used some of these sweeteners before, experiment with small
batches first before making large quantities.
Here is a summary of things to remember about canning with sugar
substitutes:Sugar is not essential for preventing spoilage of canned fruits, but
it helps preserve flavor, texture, and color. Other sweeteners may be
substituted for part or all of the sugar in your canning syrup recipe, but some
sweeteners may change the flavor and color of the fruit. |
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Discoloration in Canned Foods |
Symptom
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Cause
and Prevention
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| Does ascorbic
acid help keep fruits and vegetables
from darkening? |
Yes. Adding 1/4 teaspoon of crystalline
ascorbic acid (vitamin C) to a quart
of fruit or vegetable before it is processed
retards oxidation, which is one cause
of canned foods darkening. Ascorbic
acid preparations containing sugar can
be used with fruits in proportions suggested
by manufacturer. |
| What makes
canned foods change color? |
Oxidation may cause foods to darken
at the tops of jars. Oxidation is from
air in the jars or too little heating
or processing to destroy enzymes. Overprocessing
may cause discolored foods throughout
the containers. Pink and blue colors
sometimes seen in canned pears, apples,
and peaches are caused by chemical changes
in the coloring matter of the fruit.
Iron and copper from cooking utensils
(or from water in some localities) may
cause brown, black, and gray colors
in some foods. When canned corn turns
brown, the discoloring may be due to
the variety of the corn, to stage of
ripeness, to overprocessing, or to copper
or iron pans. Packing liquid may dissolve
coloring materials from the foods. |
| Is it safe
to eat discolored canned foods? |
The color changes noted do not
mean the food is unsafe to eat. Spoilage,
however, may also cause color changes.
Before you use any canned food that
has an unusual color, examine carefully. |
| Is it safe
to use home-canned food if liquid is
cloudy? |
Cloudy liquid may be a sign of
spoilage, but it may be caused by the
minerals in hard water or by starch
from overripe vegetables. If liquid
is cloudy, boil the food. Do not taste
or use any food that foams during heating
or has an off-odor. |
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Pink, red, blue or light purple discoloration sometimes occurs in home-canned
fruits and vegetables.
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This discoloration can happen in canned apples, cauliflower, pears, peaches
or beets. Keep all fruits and vegetables cool after you harvest them and before you can
them. For hot-pack canning, do not overcook or heat at too high a temperature.
Excessive heat alters virtually all natural food pigments. If fruit grows in very dry, hot weather, it often turns pink; you cannot
prevent this discoloration.
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Cloudiness in Liquid of Canned Foods
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Cloudiness in canned food liquid often indicates spoilage, so be careful.
Cloudiness often accompanies flat sour spoilage, but you can usually detect a
bad odor as well. Boil food 10 minutes before you taste it if the liquid is
cloudy, or if you are unsure how the food was canned. If the food does not smell
normal during boiling, throw it away without tasting. In spoiled foods, the
cloudiness will usually be very obvious.
In certain foods, cloudiness may not indicate spoilage. For example,
the starch content in over-mature peas and many kinds of dry beans can cause
cloudiness. Uneven sizing of products can also cause cloudiness. For example,
small tender peas will cook to pieces during heat processing, while more mature
peas in the same can will keep their shape. The liquid will be somewhat cloudy
under these circumstances.
In home-canned foods, hard water or salt containing impurities or additives,
may cause cloudiness. In fruits, over-ripe fruit may make the syrup cloudy.
Fermentation causes the liquid on brined dill pickles to become cloudy. In all
of these examples, the cloudiness is normal and not harmful. |
Cauliflower with a purplish tinge is frequently found in the market and it
can be disconcerting for some folks but there's nothing to worry about. Purple
cauliflower is safe to eat.
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Some cauliflower varieties have a genetic propensity to having a higher
concentration of red, purple, or blue pigments. This is the same harmless, water
soluble pigment found in eggplant, red cabbage, berries, plums and grapes. In
other types of cauliflower the colorless or white pigments will predominate.
Purpling can develop in white varieties of cauliflower if the heads are exposed
to light while developing. Usually, the leaves are tied over the heads.
If the cauliflower has a lot of purpling it is probably best to use it raw
for relishes or salads. Heat may induce a color change from purple to gray or
slate blue--especially if the water is hard or had an alkaline pH. If you prefer
to have cooked cauliflower add a little vinegar or cream of tartar (tartaric
acid) to the water.
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Red pigments in beets fade if the beets are overcooked before canning or
overprocessed during canning.
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Although it may not be appetizing, you can eat the food if the liquid is
clear, the odor is natural, and if you used the recommended processing methods,
time and temperature.
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If you used garlic in a product and the garlic has an iridescent greenish
coloring.
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This is the result of using immature garlic--it was not completely
dry. Store canned foods in a cool, dark place.
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Date: May 1989 (Reviewed June 1996) Source: University of Wisconsin
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Return to the canning menu.