Home Canning Magazine


Solutions & Problems

Home canning requires close attention to detail. Failure to follow directions can result in less than desirable products. Causes and remedies for problems which can occur in home canning are outlined here. If your question is not answered, please contact us directly via our Mailbox. [link to mailbox]

NOTE: Some problems can indicate food spoilage. Spoiled food must never be eaten. Signs of spoilage include spurting liquid and gas bubbles; soft, mushy, slimy or moldy food; cloudy liquid; sediment in the liquid; leaking jars; bulging caps; and an unnatural odor or color. Do not eat. If in doubt, throw it out!

Seal Failure

CAUSE
  • Failure to process for the appropriate time; chipped or cracked jars; failure to follow manufacturer's directions for using two-piece metal lids; food particles left on jar rim; using lids more than once; turning the jars upside down to cool breaks seal due to weight of food on lid; using old screw bands that are stretched out of shape; lids not centered on jar rim; re-tightening bands upon removal from canner damages sealing compound; too much head space causes incomplete exhaustion of air from jar and insufficient head space causes food to boil over and get trapped between sealing compound and jar rim; improper type of jar used.
  • REMEDY
  • Process following recipe directions; boil Snap Lids to soften sealing compound; leave jars undisturbed for 24 hours upon removal from canner. Apply screw bands just until fingertip tight; wipe jar rims, removing any food particles or stickiness; discard lids after opening jars; do not reuse Snap Lids. Check jars before using and discard any cracked or chipped jars. Check screw bands for stretching and warping. Replace screw bands occasionally. Center Snap Lid on jar rim before applying screw band. Leave head space recommended in recipe. Do not re-tighten screw bands after processing. Use mason jars and two-piece metal lids.
  • Jar - Seals, then unseals

    CAUSE
  • Indicates food spoilage due to improper preparation and processing; food or syrup left on jar rim dries out and allows air to enter jar; small crack or chip in jar.
  • REMEDY
  • Process using recommended time and method in recipe. Wipe jar rims before applying Snap Lids. Check jars before use. Discard cracked jars. If jar becomes unsealed within 24 hours of processing, repeat processing using proper instructions. If jar seals and then comes unsealed destroy food, spoilage is evident.
  • Jar - Broken or Cracked

    CAUSE
  • Using commercial food jars that are not designed for heat processing. Placing cool jars in boiling water; pouring cold water over hot jars in canner; failure to use a rack in bottom of canner; placing jars on cold hard surface upon removal from canner. Overtightening two piece metal lidsbuildup of internal pressure can cause breakage.
  • Internal scratches in jar which weaken glass.
  • REMEDY
  • Use mason jars which are specifically designed for home canning. Keep jars hot until ready to fill. Place jar in canner - on rack - as soon as filled. Add only hot water to boiling water canner. Pour hot water in between jars when needed. A rack lifts jars up off heat source. Cool processed jars on board, tea towel or layer of newspaper out of drafts. Apply screw bands just until fingertip tight. Use nonmetallic utensil to remove food and air bubbles from jar. Clean jar with soft cloth, not steel wool. Avoid pouring boiling water into room temperature jars or placing room temperature jars in boiling water.
  • Lid - Buckling

    CAUSE
  • Applying screw bands too tightly; insufficient head space results in excessive pressure build up inside the jar causing the lid to buckle or the jar to break.
  • REMEDY
  • Fasten screw bands gently using only your fingertips. This provides some give between Snap Lids and screw bands so that air and steam created inside the jars during processing can be exhausted from the jars. Use recommended head space.
  • Lid - Rust

    CAUSE
  • Enamel surface of lid is scratched; too little head space.
  • REMEDY
  • Discard scratched lids when preparing lids for canning. Leave the recommended head space for each food product.
  • Lid - Black Deposits on Underside

    CAUSE
  • Natural compounds in some foods react with metal to form a harmless dark deposit on inside surface of lids.
  • REMEDY
  • Avoid using lids if white enamel has become scratched. DO NOT USE if jar has become unsealed.
  • Liquid Lost During Processing

    CAUSE
  • Insufficient head space can cause food to boil over in boiling water canner, jars not completely covered with water Failure to remove air bubbles (air bubbles are forced to the top of the jar making it "appear" as though liquid was lost). Food not heated before packing into jars; food packed too tightly; steam-pressure canner not operated correctly; jars not covered with water in boiling-water canner or absorption of liquid by starchy foods.
  • REMEDY
  • Leave head space recommended in recipe. Cover jars with at least 1 inch (2.5 cm) of water during processing. Remove air bubbles. Pack food loosely. When pressure canning, pressure should not be allowed to fluctuate during processing time. Allow pressure to drop to zero naturally; wait 2 minutes before opening lid. Jars should be covered with water by 1 to 2 inches through the processing period.
  • Liquid - Cloudy

    CAUSE
  • Food spoilage from under processing; minerals in the water; starch in vegetables; fillers used in table salt.
  • REMEDY
  • Use soft water and canning salt. Process each food by recommended method, for recommended length of time. If cloudiness denotes spoilage, do not use.
  • Discolored Fruit; Fruit at Top of Jar

    CAUSE
  • Air left in the jar permits oxidation which turns the fruit off-colour. Insufficient syrup covering the fruit; too much head space left in jar or jars not processed long enough to destroy enzymes.
  • REMEDY
  • Hot packing limits discoloration of fruit and increases the vacuum obtained in the jar by decreasing amount of air left in jar. Make sure liquid completely covers fruit before sealing. Remove air bubbles from jars. Leave right amount of head space and process using recommended time in recipe.
  • Discolored Fruit - Pink or Blue Tinted

    CAUSE
  • Natural and harmless compounds in fruit react with some metals.
  • REMEDY
  • Use stainless steel cookware.
  • Discolored Vegetables - Blue Garlic, Pink Cauliflower

    CAUSE
  • Brine causes reaction which changes pigments in garlic and cauliflower. Product is safe if it has been properly prepared, processed and has remained sealed.
  • REMEDY
  • None.
  • Sediment - White Sediment in Jar of Fruit

    CAUSE
  • Starch from product, minerals in water.
  • REMEDY
  • Use soft water and follow up-to-date processing procedures.
  • Sediment - White Crystals in Grape Juice

    CAUSE
  • Presence of tartaric acid naturally occurring in grapes.
  • REMEDY
  • Ladle juice into hot, sterilized jars, being careful not to disturb crystals.
  • Discolored Fruit - Faded Color, i.e. berries

    CAUSE
  • Light in storage area caused fading. Product is safe unless spoilage is evident.
  • REMEDY
  • Wrap jars in paper, store in boxes or put in dark storage area.
  • Discolored - Foods Become Black, Brown or Gray

    CAUSE
  • Natural chemical substances (tannins, sulphur compounds and acids) in food react with minerals in water or with metal utensils used in preparing food.
  • REMEDY
  • Use soft water. Avoid using copper, iron, chipped enamelware and utensils from which tin plate has worn.
  • Floating Fruit, Vegetables

    CAUSE
  • Raw packed food. Syrup that is too heavy (too sweet) for the fruit; packing food too loosely in jar. Product lighter than liquid; food contained excessive air.
  • REMEDY
  • Hot packing according to recipe directions helps to force air out of the tissues of the food and limit floating. Pack tightly, without crushing. Food floating above the canning liquid may undergo undesirable texture and colour changes. However, as long as the food was properly prepared and processed, and the seal remains intact, the food is safe to eat. For fruit, use light or medium syrup.
  • Fermentation

    CAUSE
  • Imperfect seals, failure to process properly for correct time, improper storage.
  • REMEDY
  • Discard product if fermented. Process high acid foods in a boiling water canner for recommended times.
  • Separation in Canned Tomato Juice

    CAUSE
  • Enzymes in tomatoes cause separation of water from the tomato solids in different canned tomato products from tomato juice to crushed tomatoes.
  • REMEDY
  • To limit separation, quickly heat a small quantity of quartered or crushed tomatoes to a gentle boil. Continue to add remaining tomatoes as you cut or crush them. (Quick heating of tomatoes destroys the enzymes that cause juice separation before they have a chance to be activated.)
  • Discolored - Color Change in Tomatoes

    CAUSE
  • Acids which occur naturally in food can react with aluminum, copper, brass and iron equipment and cause the tomatoes to produce a bitter flavour and an undesirable colour.
  • REMEDY
  • Use glass or stainless steel or enamel saucepans and utensils.
  • Mold - Jam / Jelly

    CAUSE
  • Improper preparation or processing allows spoilage organisms to survive and grow. Imperfect seals; unsterilized jars and lids; warm and damp storage can also cause mold. Jar not sealed airtight.
  • REMEDY
  • Always process high acid foods in a boiling water canner. Discard products. If there is only a very small amount of mold on jams or jellies, scrape off mold plus 1 inch (2.5 cm) of the product underneath.
  • Jam/Jelly - Soft Set in Freezer Preserves

    CAUSE
  • Fruit chopped or pureed too fine, pectin not thoroughly dissolved, pectin added at wrong time; setup time too short.
  • REMEDY
  • Prepare fruit as directed by recipe. Completely dissolve pectin, follow recipe instructions and allow jam/jelly to stand for recommended amount of time.
  • Jam/Jelly Too Stiff, Tough

    CAUSE
  • Jam may be stiff because too much pectin in proportion to acid and sugar was used; cooking no-added-pectin products too long; in marmalades, failure to precook citrus rinds before adding to sugar/syrup mixture.
  • REMEDY
  • Nothing can be done for pectin-added preserves. It's not feasible to do them over with more liquid, however, they may still be tastier than store-bought. Careful measuring of fruit, lemon juice and sugar is essential. Use just ripe fruit. One quarter of the fruit can be slightly underripe. Cook only until it reaches gel stage. For jellies made without added pectin, use 3/4 cup (175 mL) sugar to 1 cup (250 mL) juice.
  • Discolored - Dark Color Jam

    CAUSE
  • Sugar and fruit overcooked. Storage area too warm. Stored for too long a time.
  • REMEDY
  • Make a small quantity of jam at a time and cook rapidly. Avoid long boiling. Store in a dark, dry, cool place. Use within one year.
  • Jam - Runny

    CAUSE
  • Under cooking; too little pectin; improper proportions of fruit and sugar.
  • REMEDY
  • If jam is really thin, try remaking it with powdered fruit pectin. If the test jar doesn't turn out right, make sure all the remaining seals are intact and that storage is cool, dark and dry.
  • Jelly - Cloudiness

    CAUSE
  • Starch in green fruit; squeezing juice from fruit and jelly poured too slowly into jars or allowed to stand before pouring into jars. Fruit cooked too long before straining.
  • REMEDY
  • Use firm, just ripe fruit. Allow juice to drip through jelly bag. Do not squeeze. Pour jelly into jars as soon as it reaches gel stage. Fill jars quickly. Cook fruit only until tender.
  • Jelly - Too Soft (jelly shifts in jar when tilted)

    CAUSE
  • Cooking too long; recipe is doubled and boiling time goes beyond the ideal time limit; cooking too slowly for too long a time; too much sugar; too little sugar or pectin or acid; not cooking long enough. Use of overripe fruit which contains less pectin and acid.
  • REMEDY
  • Sometimes you can remake it. Do not double or triple jelly recipes. Cook until jelly reaches gel stage. Use only 4 to 6 cups (1 L to 1.5 L) juice for each batch of jelly. If fruit is low in acid, lemon juice may be added. Use just ripe fruit - one quarter of fruit slightly underripe. Carefully measure ingredients.
  • Jelly - Air Bubbles in Jelly

    CAUSE
  • Air bubbles become trapped in jelly as it is poured into jars; utensil used for pouring jelly was not held close to the top of the jar or jelly was poured slowly. If bubbles are moving, spoilage is indicated. DO NOT USE.
  • REMEDY
  • Pour jelly quickly into jars, holding utensil close to top of jars. Process using recommended time and method in recipe.
  • Jelly - Formation of Crystals

    CAUSE
  • Too much sugar; sugar not completely dissolved and sticking to sides of pot; jelly mixture cooked too slowly or too long, resulting in too much evaporation of water or tartaric acid, which occurs naturally in grapes.
  • REMEDY
  • Thoroughly stir sugar into fruit. Assure cooking time is sufficient to dissolve sugar. Ladle mixture into jars instead of pouring it. Carefully wipe pan free of sugar crystals with damp cloth before filling jars. Safe to eat.
  • Jelly - Weeping (partial separation of liquid)

    CAUSE
  • Too much acid; gelling too fast; storage too warm.
  • REMEDY
  • Store product to a cool, dark, dry place. This should prevent the problem from getting worse. Weeping jelly is still usable; just before serving, decant the jelly (pour off liquid). Use just ripe fruit. One quarter of fruit can be slightly under ripe.
  • Pickles - Color, Dark or Undesirable

    CAUSE
  • Minerals in hard water, use of ground spices, use of iodized table salt, use of brass, copper, iron or zinc cookware or cooking utensils which react with acid or salt solutions can cause discoloration.
  • REMEDY
  • Use soft water, pickling salt, whole spices and stainless steel, glass or enamel utensils and saucepans. DO NOT USE PICKLES if brass, copper or zinc cooking utensils were used. Whole cloves, stick cinnamon and other whole spices used for flavouring the pickling liquid should be removed before canning.
  • Pickles - Color, Dull, Faded or Spotted

    CAUSE
  • Improper salt solution or improper fermentation; poor quality cucumbers, excessive exposure to light, minerals in hard water.
  • REMEDY
  • Follow reliable, up-to-date recipes. Select high quality, just-picked produce and store in dark, dry, cool place. Use soft water.
  • Pickles - Cloudy Brine

    CAUSE
  • Use of table salt or minerals in water can cause brine to be cloudy.
  • REMEDY
  • Use pickling salt and soft water. DO NOT USE if spoilage is evident.
  • Pickles - Hollow

    CAUSE
  • Cucumbers being too large; long time lapse between harvesting and pickling, temperature too high during fermentation. Faulty growth of cucumbers. Fermentation was too rapid or improper variety of cucumber was used.
  • REMEDY
  • Use smaller pickling cucumbers. Use cucumbers as quickly as possible after harvesting. Hollow cucumbers usually float in water, so when cucumbers are being washed, remove floating cucumbers to use for relish. Ferment pickles at optimum temperatures - 70° to 75°F (21° to 24°C). Pickling process should be started within 24 hours of picking cucumbers. Choose variety of cucumber suited for pickling.
  • Pickles - Sediment in Jar

    CAUSE
  • Anti-caking agents in table salt; starch from product, minerals in water; spoilage due to bacteria growth.
  • REMEDY
  • Use pickling salt. Follow reliable, up-to-date recipes. Process using recommended time and method in recipe. A small amount of sediment is normal in pickles. Use soft water. If pickles are soft, spoilage may be present DO NOT USE.
  • Pickles - Scum on Brine

    CAUSE
  • Surface scum while curing cucumbers is a result of yeast, mold and bacteria that feed on acid thus reducing its concentration if allowed to accumulate.
  • REMEDY
  • Remove scum as often as needed.
  • Pickles - Shriveled

    CAUSE
  • Too much salt; sugar or vinegar in pickling liquid; long time lapse between harvesting and pickling; cooking or processing time was too long. Too much salt, sugar or vinegar was added to the cucumbers at one time. Improper control of fermentation.
  • REMEDY
  • Use reliable, up-to-date recipes. Use cucumbers as quickly as possible after harvesting. Process using recommended times in recipes. Start with a weaker solution of brine,
  • sugar or vinegar and gradually add the full amount called for in recipe. Use recipe developed for modern day use. Monitor fermentation and follow up-to-date recommendations.
  • Pickles - Slippery / Soft (fermented pickles)

    CAUSE
  • Weak brine; too little salt; blossom ends of cucumbers not removed; temperature during fermentation too high; pickles not heat processed after fermentation. Pickles not kept covered with liquid, wrong type of salt used or scum not removed from top of brine. Product and jars allowed to cool before processing.
  • REMEDY
  • Use commercial vinegar of at least 5% acidity in amounts specified in recipe. Use amount of salt specified in recipe. Slice off 1/16 inch (0.2 cm) from blossom end of cucumbers before using. Use pickling cucumbers. Process using recommended times and methods in recipe.
  • Pickles - Slippery / Soft (quick process pickles)

    CAUSE
  • Pickling liquid not acid enough; blossom ends of cucumbers not removed; improper processing; moldy garlic or spices. Pickles were not completely covered with liquid; scum was not removed from top of brine; pickles were not heated long enough to destroy spoilage microorganisms or jars were not sealed airtight while boiling hot.
  • REMEDY
  • Use commercial vinegar of at least 5% acidity in amounts specified in recipe. Use amount of salt specified in recipe. Slice off 1/16 inch (0.2 cm) from blossom end of cucumbers before using. Use pickling cucumbers. Process using recommended times and methods in recipe. Scum should be removed daily during the brining process and each jar should be filled with boiling hot liquid and sealed immediately before filling next jar.
  • Pickles - Taste Strong or Bitter

    CAUSE
  • Spices being cooked too long in vinegar or too many spices used in the recipe; vinegar too strong or use of salt substitutes.
  • REMEDY
  • Follow recipe for the required amount of spices. Use vinegar with at least 5% acidity. Potassium chloride found in salt substitutes is normally bitter.


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