Canning is supposed to be a money-saver, along with being a time-saver, but when you have a gas stove where you have to fly the gas bottles in at $60 a pop, it all of the sudden isn’t so money-saving anymore. That is, unless you move out of your comfort zone of canning on the stove and start canning with coal.
Here in Congo, coal is the common fuel used by the people for cooking (if they actually had to heat their houses I’m sure they would use if for this too, but they don’t). It’s made here from wood so technically you would call it charcoal I think but let’s just keep it simple shall we? Wood is also used but coal ends up being more cost-effective for them because it lasts longer. For a poor population, cost-effectiveness is a priority.
The idea to can using coal came up after we started using our outdoor fire pit to boil water and then moved that over to a mini coal-stove that the locals use. Years ago when we were planning to come here, I had researched how to do “canning off the grid” using rocket stoves. The idea to can on a rocket stove was and still is our plan but it is going to be a part of our outdoor kitchen that we have yet to build. Building projects that require large amounts of water, such as brick work and cement, have to wait until the rainy season when water is abundant. So until we have our outdoor kitchen completed, canning with coal is the best option.
It was an experiment at first to see if it could even maintain temperature enough to keep the pressure canner up to pressure and keep a large pot of water boiling for water bath canning. As it turns out, the entire process of using coal, is easier and less daunting that I was imagining at first. It does require more patience and the expectation of only getting 1-2 loads done in the day but if you can deal with those realities, then it’s not so hard.
Coal can take 30-45 minutes to really get going after you light it so when you can with coal, lighting the charcoal is your first step. Packing the little coal burners takes a few minutes and is a messy process. We use diesel and light it with a match after its crammed full of coal. I don’t enjoy the fumes but trying to light it without an accelerant would take even longer to get it going. I have patience, but there is a limit to it.
While the coal gets going you ready your canner and as soon as the coals are nice and hot I place my canner, pressure canner or water bath pot, on the coals to “preheat” while I pack and ready my jars. Once my jars are ready they go into the canner and it gets all sealed up like usual. This is where patience is a must. The coals put out plenty of heat, but it does take time to get it up to steaming.
After allowing your canner to vent, if pressure-canning, you place your weighted regulator on your canner and watch the pressure build. I emphasize weighted regulator, the 5-10-15 kind, because you wont be able to regulate the heat enough to use a general one (like the kind that came with my old presto I would use on an electric stove in the states) that you are supposed to just watch and regulate with heat. The coal puts out enough heat to maintain a steady jiggle on my weight, without it loosing pressure. So then you begin timing your process like normal, once it’s up to pressure.
For many things that I can, one mini-stove’s worth of coal is sufficient to get everything up to temp, pressurized and processed. However there are some items that take considerably longer for processing like beans and meat that take 75-90 minutes of processing time (that’s after its already up to pressure). When I’m canning these items (I’ve been restocking on beans lately), I have to use a two-stove system to make it through the entire processing time. So after I have lit the first one and the canner is up to pressure and is processing, about half-way through or just before, a second coal-stove gets lit. Once the second coal stove is blazing hot I have to carefully transfer my canner from the first stove to the second, to keep it up to pressure and finish the processing time.
One day, with the luxury of our outdoor kitchen, I will hopefully have a coal-stove or rocket stove that will allow me to add pieces of coal to the burner to keep up pressure and will save me the hassel of lighting a second and transferring the canner. Until then, this is how it’s done here. One consolation is that I have yet to come across something that is processed in a water-bath that needs more processing time than my little coal-stoves can provide; meaning I can boil two pots at once if I want and I don’t need to transfer any boiling pots of hot water that are HEAVY. Being grateful in the little things keeps you sane.