1. Glass lids may be used for canning, however, new rubber rings must be used each time. Soften rubber rings in hot water for 5 minutes. Stretch gently onto glass lids that have been sterilized in boiling water for 15 minutes or as required (see Canning at High Altitudes). After jar is filled, place lid on clean jar rim. Apply screw band tightly and then turn back 1/2 inch (1.25 cm) to allow the air to vent during processing. Once processing time is complete, carefully retighten the screw band immediately after jars are removed from canner. Do not turn jars upside down as seals may be broken.
2. Any deep pot with a lid, such as a stock pot, that allows for at least 1 inch (2.5 cm) of water above jars may be used in place of a boiling water canner. A rack, such as a cake cooling rack, may be used to elevate jars off bottom of canner. A deep pressure canner may also be used. Place the lid loosely on the pressure canner. Do not lock lid into place and leave vent open so that steam escapes and pressure does not build up inside.
3. Pressure canning fruit is safe but is not recommended. The texture of pressure canned fruit is very soft and fruit may have an overcooked flavour.
4. Oven canning and open kettle canning are outdated and unsafe methods for preserving. In oven canning, the dry uneven heating was insufficient to destroy spoilage microorganisms and could also have caused jars to explode. In open kettle canning, food was cooked and then packed into hot jars and sealed without processing. The temperature obtained in open kettle canning was not high enough to destroy all spoilage microorganisms that may have been present in the filled jars.
ATCO Blue Flame Kitchen information and recommendations contained in this publication have been researched and are in accordance with current guidelines published by Bernardin Ltd. and the Cooperative Extension Service, University of Georgia. We acknowledge their assistance. The Bernardin Ltd. "Guide to Home Preserving" is available at retail outlets in Alberta.
The methods and procedures outlined in this publication are recognized as safe. Many factors over which we have no control may cause spoilage. ATCO Blue Flame Kitchen assumes no responsibility for any failures or spoilage that may occur.