Canning with Lug Lids
How do you can with lug tops? Do you loosen top place in a boilng water canner and then tighten right away or just tighten and not tough it after?
I really need to know. I ordered 144 gourmet jars and they came with professional lug tops without the little button on top that inverts when sealed. so I don't really know if they are sealed? Any guidance will be appreciated.
Answer--Canning With Lug Lids: One-Piece Dilemma
by Cheryl M. Johnson
The USDA not endorsing a method or product does not automatically make it unsafe. The reasons for endorsement are many, and not all have to do with food safety.
I have canned with reused lug lids for many years (I am 55), and my mother did before me. I grew up eating food canned in such jars, and we never had any spoilage at all--ever. My mother--and I--also used/use two-piece lids right along with the lug lids, in the same pressure or water-bath batch, and there is no difference to the finished product.
It helps to have a comprehensive knowledge of microbiology and sterilization methods, which I do have, to know what the indicators are that jars are sealed and that food is safe. The USDA gives far stricter guidelines than are necessary, to err far on the safe side.
You can process food with used lug lids exactly as you do with two-part lids. The one tip I would give is not to tighten the lid all the way when placing it on the jar ready to process. It should just feel snug, but not to the point where it feels it couldn't go any tighter. The reason for this is that the lids tend to seal REALLY WELL when tightened completely, and often I can't get them open with my bare hands afterward, or even with the help of rubber gloves, running under hot water and striking, etc. A few have even defeated my husband! I've had to buy jar openers to get some off--but you can be sure the food was well and correctly sealed! (Piercing the lid would break the vacuum, and then it would be easy to get off, but I would also have rendered the lid unusable and, since I reuse the lug lids, I don't want to do this.)
The two points that are important in processing food when canning are:
1. The seal of the lid;
2. The temperature and length of time of the processing.
When these two points are correctly met, your food will be safe.
First, regarding the temperature: Data are empirical regarding what temperature different foods should be processed at, and what length of time. The USDA, The Ball Corporation, and other technical and reliable sources have tables that give this information, as well as our individual canner instruction books. When the required time and temperature is met, the food will be sterile--no question.
Second, regarding the seal of the lid: The lid sealing has to do with two points: 1. The sealing part of the lid is in contact with the jar rim all the way around, with no breaches; 2. The hot food in the jar cools and contracts to cause a vacuum in the jar, which is why the lid pops or goes concave. Once the lid is sealed as a result of the correct processing time and temperature, and has not been removed and replaced while cooling off, the sterility of the jar contents is assured AS LONG AS THE JAR RETAINS ITS ORIGINAL SEAL. Spoilage of food is caused by microorganisms entering the food. It is the above processes that eliminate microorganisms from the food in a processed jar.
The QUALITY of canned food is a different subject altogether from spoilage. As canned foods age, the cells of the food slowly break down, and this can affect the food value (vitamin, mineral content) of the food. Conditions that slow this process are: 1. Absence of light; 2. Cool temperature.
Nice article Cheryl... thank you.
My disclaimer regarding the USDA. I agree that there are probably many factors that are considered when the USDA recommends or endorses products or methods. They are still a valuable resource and their suggestions should be seriously considered.
Personally, if I can reasonably follow USDA guidelines... I do.
Canners and home preservers need to make informed decisions.