Weck Home Canning Instructions

05.02.11 Weck Home Canning Instructions

weck canning jars

It might be easier than you think to can food and beverages. It's fun and satisfying and brings you the recognition of family and friends, as well as saving you money!

Weck has been providing canning equipment in Europe since 1900. One of the many benefits of Weck canning jars is that they have glass lids, which means no rust and no BPA coatings that are found on metal lids.

The following instructions are from the Weck Company:

These rules are listed in the approximate order of the canning procedure:

1. Before starting to work, examine all jars and lids for possible small chips, knicks and other defects by running your finger tips around the jar rim. Should the sealing rim of a jar or lid be chipped or otherwise damaged, discard it, since it will not permit an airtight seal.

2. Cleanliness is especially of utmost importance. Wash canning jars in hot soapy water, then rinse them in clean, hot water. If mold has formed in used jars (because they were stored in a damp cellar), submerge jars in boiling water for ten minutes. Mold and fungus spores are not killed at temperatures below 212°F, so the temperature of a dishwasher (about 140°F) is not high enough.

3. Carefully examine rubber rings before processing. Possible cracks can be best detected by holding the rubber ring between the thumbs and forefingers of both hands and tugging lightly while turning bit by bit. A safe seal can only be achieved by using perfect rubber rings. Always use new rubber rings.

4. Submerge rubber canning rings in boiling water for 2-3 minutes. Leave them in the hot water until they are needed. It is not necessary to sterilize jars and lids unless the processing time is less than 10 minutes. (Fruit juices are processed only 5 minutes, for example.) To sterilize jars and lids, boil them for 10 minutes.

5. When filling hot foods (example, precooked hot jam) into the jars, place the jars on a towel, rack or wooden cutting board to keep jars from cracking.

6. What is the proper headspace? 
Pack foods up to within ½ inch of the jar rim; add liquids as well as sugar syrups to the same height. Some foods can be packed raw into jars with boiling liquid added. Other foods should be precooked and packaged hot with hot liquid into jars. See each recipe for packing instructions.

7. Sweetening (natural and artificial)
. According to long experience, recently confirmed by new research, sugar should not be added dry to the foods, but as syrup. Add the required amount of water and bring the syrup to a rolling boil for a short time. Pour the hot syrup over the food in the jars. Artificial sweeteners should not be used for canning. They can be added at the table.

8. After filling the jars, carefully wipe the jar rim.

9. When using the WECK Round Rim jars, apply the rubber ring to the sealing rim of the lid. It is best to apply the rings before filling the jars. Leave the lids with the attached rings in hot water, until both can be placed together on the jar. The uncomplicated sealing method of the WECK jars prevents dislodgment of the rubber canning ring and seals which are not airtight can be avoided.

10. Closing the packed jars by means of spring clamps:

During processing, the jar is then tightly closed by means of two canning clamps made of rust-proof stainless steel and having an exactly adjusted, permanent spring action. Hold the canning clamps, arranged directly across from each other, into the stacking depression in the lid. Then press them down until they click under the protruding rim of the jar.

11. In the canner, the jars should be placed on a rack. It does not matter if the jars touch each other or the kettle wall. They should not, however, be wedged into the canner so tightly that the jars cannot move at all; a little space for jar movement is necessary for good results.

12. After you have placed the jars on the rack in the canner, fill water into the canner high enough so that the jars are completely submerged in the water. If you place two or more rows of jars on top of each other, or if low jars are processed together with high ones, the water level will always depend on the height of the highest jars. If two layers of jars are being processed, a second rack must be used between the layers so that the water can circulate freely around all the jars. The jars should be completely covered by one to two inches of water. The spring action of the clamps keeps them sealed, and no water from outside can enter the jars.

13. Important:
When you start to process the jars, the temperature of the water bath has to have approximately the same temperature as that of the jar contents. Jars filled with raw-packed food therefore must be started in warm water, jars filled with hot food (in the case of precooked food) accordingly in hot water. In no case, however, should you add hot or boiling water to the canner for jars filled with raw-packed food; the water reaches the prescribed processing temperature too quickly, but the jar contents are not yet heated up to the required temperature. Thus, the thermostat merely indicates the temperature of the boiling water, but not the temperature of the food in the jars. The results: the processing times prescribed by the recipes are insufficient; failures will then be inevitable because not all the bacteria and spores have been eliminated inside the jar; the processing temperature of the interior was simply too low. When placing the jars in the canner, it is absolutely necessary that the food in the jars have roughly the same temperature as the water that is poured into the kettle. And remember: always heat the canner slowly.

14. When processing your jars, carefully observe the temperatures and heating times specified in the recipe section of the WECK Home Canning Guide. Do not cut down the processing times under any circumstances! The processing time starts when the canner reaches a full rolling boil. The time needed to heat up the water in the canner does not count! The thermostat then holds the set temperature by controlling the heating element which keeps the water at a constant temperature.

15. When the required processing time is up, remove the jars from the canner. Place jars on a rack, wooden cutting board, or towel, and allow them to cool down undisturbed. The jars should not cool down in the water bath, since in that case the heating time is lengthened and the canned foods may become too soft or turn unsightly due to overcooking. Nor is it advisable for the same reason to cover the processed jars with a towel. Keep jars away from a cold draft, and avoid placing them on a cold surface or cooling them quickly by means of cold water.

16. Very important:
After removing the processed jars from the canner leave the canning clamps on the jars until the jars are completely cooled. When the jars are cold however, it is absolutely necessary to take off the clamps. They are now no longer required to keep the jars sealed. If you remove the canning clamps, you can easily check to see if the jar is actually sealed by trying slightly to lift off the lid (so-called lid-lifting test). In the first few days after processing you should carry out sealing checks of your jars by this lid-lifting test and always before you open each jar. Note: in the seal on the WECK jars, the pull tab of the rubber ring on the sealed jars quite clearly faces downwards. If you arrange the jars correctly on your shelves, you can simply check them by visual inspection to ensure that they still face down. This facet of the seals will prove the stackability of the WECK jars and arrange them on top of each other.

17. In the storage area, the jars should not be subjected to direct sunlight. The room has to be kept frost-free. It is not necessary that the canned jars be stored in a cool basement or cellar. It is sufficient if they are kept at room temperature.

18. In order to open your canning jars, pull the protruding tab of the rubber ring, until you hear a "ps-s-st", indicating that air has been sucked into the jar. The vacuum in the jar has thus been equalized, and the lid and rubber ring can now be easily taken off. Never use sharp objects, such as knives, scissors, or screwdrivers, since they will damage the jar rim or lid. If the rubber rings sticks to the jar or the tab is torn off, the jar can be opened easily by attaching three canning clamps and placing the jar upside down in hot water for several minutes.


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. 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 overripeness 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 the Weck Canning Guide 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. 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.

comments powered by Disqus

Where living healthy supports your school.