Technical Mistakes
1. Either the jars or the lid or the rubber ring had minor defects or damage which you had failed to notice before.

What to do? In most cases such jars open readily as they are cooling down or shortly afterwards. The food is then edible and can be consumed immediately. It can also be processed once more after exchanging the faulty part; process then according to the time and temperature indicated in the recipe. Always use a new rubber ring.

2. The canning clamps were not mounted properly. Such jars open immediately after processing.

What to do? Follow the reprocessing instructions under reason #1

3. Lid or jars crack during processing or cooling (very rare).
What to do? Discard cracked lid or jar and food.

The rubber canning ring loses its sealing property:

1. Although the rubber ring was not defective and was of good quality, you may have applied it improperly, or it was pushed out of place during processing because the jar was packed too high. The latter problem has been eliminated by the new closure on the WECK Round Rim jars.

What to do? Follow the reprocessing instructions under Technical Mistakes - #1.

2. When you are processing either sweet-sour fruit or pickles, packing the jars too high or excessive heating of the hot vinegar solution may have negative effects on the rubber canning ring: the jars will not seal properly, because the rubber ring tends to become very wavy and stretch under the influence of the hot vinegar solution.

What to do? Follow the reprocessing instructions under Technical Mistakes - #1.

Mistakes during processing:

The temperatures and/or processing times as indicated in this cookbook were not observed ("Rules for Success", No. 14). As a consequence, not all the bacteria in the jar were destroyed. After several days or even weeks decay sets in and forms gasses which push up the lid.

What to do? Proceed with utmost caution!Food is spoiled and must be discarded so that children or pets have no access to it. Boil food 30 minutes before discarding it.

Faults in food itself

1. Improper fertilizing of crops (for example, excessively or too late in the season).

2. Growth of the food under abnormal weather conditions, for example rapid ripening due to extreme summer heat or ripening in very rainy weather.

3. Fruit harvested too late; tardiness in harvesting results in over ripeness or a slight sickly sweet flavor of beginning decay.

4. Harvested fruit were exposed to the heat of the sun for too long during the harvest or during transport and therefore have started to decay already.

In these cases a,b,c and d, it should be considered that the processing times and temperatures as given in the recipes in this book are computed for normal, flawless food. Using such food as described in a, b,c, and d is always a risk. Only good quality food should be used for canning.

5. Without your knowing it, the fresh food carried invisible molds or mold spores which can generally only be destroyed at 212°F (refer to page 8 and "Rules for Success", No. 2). They will propagate in the sealed jar as long as there is any oxygen left in the head space, and form a sheet of mold on the surface.

What to do? Discard the food!

Final comment and warning:

Whenever you find a jar with its lid lying loosely on top, whether it is when performing the lid-lifting test or shortly before using the jar, always consider this signal as a significantly important warning which you should respect. Never consume any food out of such jars. Do not allow anyone else access to it, even if it's in the garbage. In case you wish to use jars of various sealing types, including used commercial jars, do not ever neglect your own personal safety; Only canning jars that are sealed by natural air pressure, that is, in accordance with the time-tested WECK method, provide an adequate warning signal in the form of the loose-lying lid.

Jars with mechanical closures (screw-type, thread-type, or wire-bail type) do not have this warning signal.