Sealing Problems Canning Beef Stock

It's that time of year to get a bit of canning done before the busy canning months start.  This is a great time of the year to clean out the bones from the freezer that have been saved to make stock to free up a bit of freezer space in preparation for the arrival of our beef on the hoof purchase.  I like running a full load (16 - 500 ml jars) in the pressure canner.  A couple of weekends ago I decided to take a bit of time to can beef and turkey stocks.  I ended up using two large beef soup bones for the beef stock and 2 turkey carcasses for the turkey stock.

I have been testing the 4ever Recap reusable canning lids.  The lids performed nicely as expected until I ran the first load of beef stock.  Pictured is the first load of beef stock.  The five jars on the left had Tattler reusable lids with one seal failure.  The six jars in the middle had metal snap lids with no seal failures.  The five jars on the right had the 4ever Recap reusable lids with three seal failures.  In terms of seal failures, a total of 4 of 16 or 25% seal failure is certainly not acceptable!

At this point, many home canners would blame the reusable lids and go back to using the metal snap lids.  That certainly happened when the manufacturers changed the metal lid colour from gold to silver, resulting in many complaints that the silver lids had a higher seal failure.  In reality they did not as the only difference was the colour.  Seal failures again increased when the manufacturers changed the plastisol sealant on the metal jars.  The old sealant required the lids to be scalded but the new sealant only needs to be warmed.  Over heating the new sealant results in seal failure so the real reason for these seal failures was user error.

I can't say I was happy about the seal failures but had to deal with them which meant doing a bit of trouble shooting.  I put the stock into the refrigerator then washed the lids and rings well and set about making the turkey stock.  The plan was to re-process the beef stock along with processing the turkey stock.  Re-processing is as much work as the original processing.  While stock can handle re-processing, some home canned foods cannot.  If this type of food does not seal, the only choice is to refrigerate and use within a couple of days. 

All went well with filling and processing the jars.  I ran the seal failures first even though I don't like running only a few jars in the canner.  That 1 - 500 ml jar beef stock with Tattler lid and 3 - 500 ml jars.  I ran the turkey stock in a separate load.

The following morning I removed the bands.  Pictured are all of the jars beef and turkey stock (sealed and unsealed).  The jar with the Tattler lid and one with a 4ever Recap lid that did not seal from the first processing sealed with the second processing.  The two unsealed jars of beef stock from the first load to the right had 4ever Recap lids.  They failed to seal with the second processing.  All of the turkey stock sealed.  By now I was getting a bit frustrated, having run the canner three times and still getting seal failures!  In my mind though, there had to be another problem besides just the 4ever lids because of the three that had not sealed in the first load, one had sealed in the second load.  The third load had no re-usable lids and no seal failures.

I was determined to find out what was causing the seal failures.  Meat products can be difficult to home can because there is a bit of natural oil in the product.  If that oil gets onto the rim of the jar where the ring/gasket or plastisol sealant sits, it can cause a seal failure.  If you watched the video of jars of beef stock fresh from the pressure canner, it is easy to see how boiling stock could actually be forced between the lid and rim of the jar.  In this case, proper headspace had been left so I did not feel that leaking stock was the problem.  There was no indication of any leakage in the pressure canner, reinforcing this conclusion.

Even though I used a funnel to fill the jars, I decided to use isopropyl alcohol (rubbing alcohol) to wipe the rims of the jar to ensure there was no oil on them. I normally do not do this as my jars go through the dishwasher just before using them so there should be no oil unless spilled on during filling which is unlikely but still possible when using a funnel.  Many home canners routinely wipe the rims of their jars with vodka or white vinegar but I use a paper towel dampened with water.

As I was filling the three jars (2 beef stock re-cans, 1 turkey left-over from run 3), I noticed a problem with the metal band seating on the threading of one of the jars.  At one time, occasionally there would be a problem with a band seating.  This seemed to be isolated to using newer bands on older Imperial mason jars but I haven't ran into that problem in years.  The jar in question was a Golden Harvest, manufactured by Jarden Home Brands in the US.  This is now the same manufacturer of Ball, Kerr and Bernardin mason jars.  This particular 500 ml jar came from a box of jars filled with food that I had to clean out.  The box was purchased in 2010 from Home Hardware so the jars are not old although that doesn't mean the jar itself could be older.  At any rate, it is not an old jar.

Both Tattler and 4ever Recap reusable lids require tightening the band then turning back a quarter an inch for processing.  As I tightened the band, it popped off.  I tried again with the same results.  I quickly poured the hot stock into another prepared jar, positioned the lid and tightened the band then turned it back.  Once the jars were safely in the processing, I turned my attention to the jar.  After trying four different bands, I realized the problem was not with the bands at all but rather the threads on this jar were defective.  They were just off slightly yet the first time through the canner, a band had held just enough but did not tighten enough for the 4ever Recap lid to form a seal.

There is a misconception that new mason jars are flawless.  This simply is not the case.  I have seen brand new canning jars with air bubbles in the glass, small chips in the rim, a droop in the rim and slightly misshaped openings.  It happens.  A defective thread is a difficult one to catch and in fact if a band catches just enough, you might not catch it especially if using a boiling water bath canner.

The two jars of beef stock, one with fresh jar and 4ever Recap, the other with same jar and 4ever Recap sealed.  The turkey stock jar with a 4ever Recap lid sealed as well.  I marked the jar with the defective rim.  Unfortunately this jar will not be suitable for canning or dry storage requiring a screw band closure.  It can however, be used for vacuum sealing.

Finally, after running the canner four times all my jars of stock were sealed.  Two of those loads experienced seal failures.  In total, there were 4 seal failures, 1 was Tattler, the other 3 were 4ever Recap lids. At the end of the fourth run, all lids had sealed.  The only problem I found that accounted for one seal failure was the defective threads on one jar.  I still have no idea why the other 3 lids failed to seal originally.  There was nothing apparent that would contribute to the seal failure.  I do not feel that any of the seal failures were due to the lids considering two brands of reusable lides were affected.  It is possible that I did not turn the band back enough when putting the reusable lids on or I may not have tightened the band enough when just out of the canner even though I took great care during both steps. 

In comparison to the Tattler reusable lids, the 4ever Recap reusable lids perform just as well.  I do like the look of the 4ever Recap reusable lids that have a bit of a raised ridge on top giving them a rather unique look.  One thing I did notice because I reused both lids and rings in this canning session was the absence of sealing marks on the silicone rings.  I'm looking forward to doing a lot of canning reusing the 4ever Recap lids and rings.  It is encouraging that the silicone rings should not wear out under normal use! [retracted November 10, 2013 as all jars using the 4ever Recap reusable lids lost their seals during storage1
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