Problem |
|
Cause |
|
Prevention |
|
I. CANNED FOODS |
Loss of liquid from glass
jars during processing. Do not open to replace liquid. (Not a
sign of spoilage)
| 1. |
Lowering pressure in canner
suddenly after processing period. |
1. |
Do not force pressure down by
placing canner in a draft, opening the vent too soon, etc. Allow
pressure to drop to zero naturally; wait 2 minutes before
opening. |
|
2. |
Fluctuating pressure during
processing in pressure canner. |
2. |
Maintain a constant
temperature throughout processing time |
|
3. |
Failure to work out air
bubbles from jars before processing. |
3. |
Remove by running a plastic
spatula or knife between food and jar. |
|
4. |
Improper seal for the type
closure used. |
4. |
Follow the manufacturer's
directions for closure used. |
|
5. |
Jars not covered with water in
water bath canner. |
5. |
Jars should be covered with 1
to 2 inches of water throughout processing period. |
|
6. |
Starchy foods absorbed liquid. |
6. |
None. |
|
7. |
Food packed too tightly in
jars can boil over during processing and start a siphon. |
7. |
Leave the appropriate
headspace. |
|
Imperfect seal (discard
food unless the trouble was detected within a few hours) |
1. |
Chips or cracks in jars. |
1. |
Examine carefully by rubbing
finger around the mouth of the jar. |
|
2. |
Failure to follow recommended
directions for closures used. |
2. |
Follow manufacturer's
directions. |
|
3. |
Particles left on mouth of
jar. |
3. |
A clean, damp cloth should be
used to remove any seeds, seasonings, etc. that prevent a
perfect seal. |
|
4. |
Using old closures that should
be discarded. |
4. |
Do not reuse rubber rings and
self-sealing metal lids. Do not try to use rusty bands. |
|
5. |
Lifting jars by tops or
inverting while hot. |
5. |
Use jar lifter for removing
jars from canner, graspong below tip. Leave in upright position. |
|
6. |
Fat on jar rim. |
6. |
Trim fat from meats. Add no
extra fat.Wipe jar rim well. |
|
Product dark at top of jar
(not necessarily a sign of spoilage) |
1. |
Air left in the jars permits
oxidation |
1. |
Remove air bubbles before
sealing jars. Use recommended head space. |
|
2. |
Insufficient amount of liquid
or syrup. |
2. |
Cover product with water or
syrup. |
|
3. |
Food not processed long enough
to destroy enzymes. |
3. |
Process recommended length of
time. |
|
Cloudy liquid (sometimes
denotes spoilage) |
1. |
Starch in vegetables. |
1. |
Select products at desirable
stage of maturity. Do not use overmature vegetables. |
|
2. |
Minerals in water. |
2. |
Use soft water. |
|
3. |
Fillers in table salt. |
3. |
Use pure refined salt. |
|
4. |
Spoilage |
4. |
Process by recommended method
and for recommended time. |
|
Color changes that are
undesirable |
1. |
Contact with minerals such as
iron, zinc or copper in cooking utensils or water. |
1. |
Avoid these conditions by
using carefully selected cooking utensils. Use soft water. |
|
2. |
Over processing. |
2. |
Follow directions for
processing times. |
|
3. |
Immature or over-mature
product. |
3. |
Select fruits and vegetables
at optimum stage of maturity. |
|
4. |
Exposure to light. |
4. |
Best to store canned foods in
a dark place. |
|
5. |
May be a distinct spoilage. |
5. |
Process by recommended method
and for recommended time. |
|
6. |
Natural and harmless
substances in fruits and vegetables (pink or blue color in
apples, cauliflower, peaches, or pears) |
6. |
None. |
|
Sediment in jars (not
necessarily a sign of spoilage) |
1. |
Starch in vegetables. |
1. |
Select products at desirable
stage of maturity. |
|
2. |
Minerals in water. |
2. |
Use soft water. |
|
3. |
Fillers in table salt. |
3. |
Use pure or refined salt. |
|
4. |
Yellow sediment in green
vegetables or onions. |
4. |
None (natural occurrence) |
|
6. |
Spoilage. |
6. |
Process by recommended method
and for recommended time. |
|
Spoilage |
1. |
Incorrect pressure. |
1. |
Gauge should be checked every
year for accuracy. |
|
2. |
Incorrect timing. |
2. |
Follow directions for timing. |
|
3. |
Incorrect method used. |
3. |
Low acid vegetables and meats
must be pressure canned for safety. |
|
4. |
Poor selection of fruits and
vegetables. |
4. |
Select product of suitable
variety and at proper stage of maturity. Can immediately after
gathering. |
|
5. |
Poor seal on jar. |
5. |
Check jars and lids for
defects. Wipe jar rim before closing. Don't overfill jars. |
|
Floating (especially some
fruits) |
1. |
Over processing fruits and
tomatoes destroys pectin. |
1. |
Follow directions for
processing times. |
|
2. |
Fruit is lighter than syrup. |
2. |
Use firm, ripe fruit. Heat
before packing. Use a light to medium syrup. |
|
3. |
Improper packing. |
3. |
Pack fruit as closely as
possible without crushing it. |
|
II. CANNED JUICES |
Fermentation or Spoilage |
1. |
Failure to process adequately. |
1. |
Juices should be processed in
boiling water bath. |
|
2. |
Imperfect Seal. |
2. |
Use recommended methods and
processing time. Use perfect jars and fittings. |
|
3. |
Air left in jars. |
3. |
Proper processing will exclude
air from jars. |
|
Cloudy sediment in bottom
of jar. |
1. |
Solids in juice settle. |
1. |
Juice may be strained and made
into jelly. Shake juices if used as a beverage. |
|
Separation of juice
(especially tomato) |
1. |
Enzymatic change during
handling (after cutting) |
1. |
Heat tomatoes quickly to
simmering temperature. |
|
Poor flavor |
1. |
Immature, overripe, or
inferior fruit used. |
1. |
Use only good quality, firm,
ripe fruit or tomatoes for making juice. |
|
2. |
Use of too much water for
extracting fruit juice. |
2. |
Use only amount of water
called for in directions. No water is added to tomatoes. |
|
3. |
Improper storage. |
3. |
Cool, dark, dry storage. |