|Lid lifting test for seal|
Seeing this summer of abundant produce as an opportunity to test how good these reusable lids and
rubber rings are, I used them, opened some jars, and reused them. I used them both in BWB and in pressure canners. My observations are as follows:
1) Those processed using BWB, the lids were easy-peasy.
2) Those processed using pressure canner, I had varying results. Probably depending on the viscosity of the liquid, or the headspace, or how tight or how loose I closed the bands...sigh...some sealed and popped in okay. Some did not seal at all (probably boil overs are responsible so I needed to increase the headspace on reprocessing), some sealed but lids did not pop in (questionable complete removal of air).
3) In some reused lids, they did fine still. But I recently found a jar that I canned that seemed to seal but the lid remained popped up, which, to my dismay, remained popped up after opening and washing. You see, I thought the reason it was popped up prior to opening despite a good seal was that I tightened too much that the air had a hard time escaping, so that the increase in temp and volume only pushed the lid up more than it pushed the air out through the rubber ring. I expected the lid to get back to its original shape after pressure equilibrium is achieved upon opening the jar. It did not.
Click on the photo to read the labels...
|Comparing the popped up used lid, the depressed used and unused lids|
Now I am thinking, if I reuse this particular lid, I would not have the popping in of lid as a visual cue that the processing created a vacuum (removal of air is a key factor that is responsible in keeping the quality of the canned food. Vacuum is lack of air. Vacuum is created by pushing the air in the headspace out during the increase in temperature, either by BWB or pressure canner. Lowering temp then contracts the volume, so the vacuum created sucks in the lid, and seals the jar.) I do not know if vacuum produced in processing will have enough strength to suck in this popped up lid if I reuse it. The only gauge I will have will be the lid-lift test 24-48 hrs after processing.
Well, there really is no other option for reusable canning lids/rubber rings, I guess, and I still have several hundreds of unused reusable lids/rings that I am stuck with. Other than that freaky lid, it seems that most users are completely satisfied (although I know that the survivalblog author spent some time getting used to the Tattler lids as he also had varying degrees of unsuccessful outcomes like I had). Maybe with practice I will get better in time.