While many home canners like myself can year round, the busy home canning season (mid-May to mid-October) is just around the corner. Home canning is a very satisfying and rewarding frugal activity. It saves a tremendous amount of money! I've been home canning well over thirty years so know what to expect and what to troubleshoot if something goes wrong. Those new to home canning often panic thinking there is a problem when what they observe is a natural part of the process. They are also prone to those accidents that can cause food spoilage and/or physical harm.
At each step of the way, the home canner is dealing with glass that can break due to thermal shock and hot foods that can cause rather nasty burns. A safety rule is children and pets should not be in the canning area. If you must have either in the kitchen when canning, set up a safe zone so they do not accidentally get in the canning area. Aside of avoiding canning when tired or distracted (easier said than done), I minimize the risk for both by:
- prepare ahead - Everything I need for that canning session is ready to use in the order it will be needed.
- avoiding thermal shock - Glass can break if it is cold and a hot liquid is poured into it or if a canning jar is placed into the canner with too much of a temperature difference. I keep everything hot! The jars are hot, the food is hot and the canner is hot ready for the hot prepared jars. Even though my counter top is ceramic tile it could cause thermal shock during the filling stage and when the jars are removed from the canner. I always work on a cork trivet when filling the jars which eliminates any thermal difference. I place hot jars from the canner onto a folded t-towel to cool. Jars being removed from the canner are particularly susceptible to thermal shock if they are hit with a cold draft. During the canning process and jar removal, I close the patio door (we don't have a kitchen window), turn off the exhaust fan if it is on and turn off the ceiling fan. Cooling jars are always placed so they will not get a draft until they reach room temperature.
- personal safety - I have my hair tied back and wear slip proof socks, capris and a t-shirt when canning. I don't wear anything loose or baggy that could catch on canning equipment. I keep a damp t-towel to clean up any spills on the floor as they happen. I keep another damp t-townel handy to wipe any spills on the counter. I make sure the dishwasher is empty before starting to can so any utensils or dirty dishes go immediately into the dishwasher as to not clutter up the counter.
I processed 16 - 500 ml jars of beef stock in the pressure canner yesterday. Meat stocks are low acid so must be processed in a pressure canner. They cannot be safely canned in a boiling ,bath canner! Jars are most susceptible to breakage during the filling stage, loading into the canner and removing from the canner. Here is a video I took that will give you a bit of a perspective on jars just out of the pressure canner.
The video is of beef stock just out of the canner. The lids to the left are Tattler reusable lids, the middle are metal snap lids and to the right are the 4ever Recap reusable lids I'm testing. A pressure canner processes at 240°F rather than the 212°F of a boiling water bath canner. Foods taken out of a boiling water bath canner are hot. Foods taken out of a pressure canner are hotter! If you look close you will see the contents still boiling in the jars. The contents will continue to boil for ten minutes or more. That means if a jar were to break, you have a very good chance of being hit with shattering glass as well as boiling food. The second thing you will notice is the ping. Home canners love to talk about the ping! It is important to realize that the ping only occurs with the metal snap lids. There is no ping with reusable lids (eg. Tattler, 4ever Recap, glass inserts). There are two types of pings. The first type of ping is what you are seeing right from the pressure canner in response to the boiling contents of the jars. This pinging will continue until the contents cool enough to form a vacuum at which time there will be a final ping. The first type of ping does not occur with foods processed in a boiling water bath canner.
The first type of ping on pressure canned foods explains why leaving the proper amount of headspace when filling jars is critical. The boiling contents can force their way between the lid and rim of the jar which in turn can cause seal failures. Not enough headspace can also cause pressure on the lid which can make the lid buckle, also affecting the seal. Some foods are quite prone to leakage when being pressure canned especially dried beans. Even if your jars lose liquid or there is signs the jars leaked into the canner, do not panic. Remove the jars for cooling. Once cool, check the seal. If they have sealed, they are fine so simply wash, label and store. If one or more did not seal, either reprocess or refrigerate and use within a couple of days. Reprocessing is every bit as much as the initial processing right from heating the jars and food, filling and timing. In general, I tend to avoid reprocessing if at all possible. It is not cost effective to run the pressure canner to reprocess only a couple of jars. If I'm canning something similar later in the day or the next day I will run those jars with it, otherwise I freeze or refrigerate.