How To Can Over A Wood Fire

How-To-Can-Over-A-Wood-FireWhen my husband first started to suggest that we needed to think about prepping, I have to admit…I drug my feet a little. It just seemed like an unnecessary expense for us as a newly married couple. Even so, we found ways to stretch our income in order to build our preps. We learned a lot back then and now, over ten years later, we’ve taken preparedness to the next level. We live and work on our own off grid homestead, powered only by solar and wind. Because we live without refrigeration, food preservation is very important to us. If you had told me when we first started prepping that I would be canning all of our garden produce, dry beans, and pastured as well as hunted animals, over a wood fire, I’m not sure I would have believed you! But here I am doing it! Last summer and into the fall, I put up about 600 jars of canned food. I canned all of them over an open fire.


I love that there is so much information out now about prepping and self-sufficiency. I learn a lot from others who have written about things that I want to try. There’s a lot of information about home canning and much of it is very helpful. But canning over a wood fire? It seems that not many do it anymore. I have heard stories of old-timers doing it. I even heard one that used an old cast iron bathtub with a fire built under it! But they were just stories, with no concrete instructions to follow. So, I felt like I needed to just dive in and figure it out myself, especially for pressure canning over a wood fire. Yes, pressure canning! It can be done! Here are my tips for how to do it.

Practice Safe Canning

I cannot stress this enough! Familiarize yourself with safe canning practices and only use recipes and instructions that have been deemed safe for canning. I had only done a small amount of water bath canning before canning over a fire, and never pressure canning. But I was very familiar with safe canning practices and all the instructions involved. It’s important to make sure you know what you are doing before you throw in the added variable of a fire. Always read your pressure canner’s instructions carefully before you get started and familiarize yourself with your canner.  I use a highlighter to mark important things in mine and even though I know what I’m doing, I always try to review them as canning season approaches.


Short Processing Times

If you have never canned over an open fire, start by canning foods with short processing times. In the early summer, one of the first things to come in from our garden is green beans. They were the first thing that I pressure canned over the fire. They worked very well for my learning curve because the processing time is short, only 20 minutes for pints and 25 minutes for quarts. A short processing time helps when you are first learning how to control your fire. Processing times for canning foods like dried beans and meats are much longer and it takes some practice to be able to control and feed your fire for that long.


Think About the Weather

Always check the weather before you get started.  A rainy day could really hinder your canning.  You don’t want your canner to get rained on because water on top of it reduces the pressure inside. On the other hand, hot sunny days are miserable! I much prefer to use the evening hours after dinner and after the sun drops below the trees. It is much more enjoyable when I’m not working in the heat of the day. But without electricity, I have to plan to be done before dark, which means I can’t do multiple loads of jars in my canner.

Have Helpers

It helps to have helpers. Canning is a family affair for us. There is much to do: picking the harvest, butchering the animal, cutting up the vegetables or meat, pumping the water, and collecting the green-beansfirewood and kindling. We all have our jobs to do. Canning over a wood fire is also more labor intensive than using a stove. The fire needs constant attention and a helper is so important to have when you need to take a break.

Have the Right Tools

Of course, you will need the regular canning tools like a canning funnel, wooden spoons, ladle, jars/lids/bands, and a jar lifter. But canning over a fire requires a few extra. A chainsaw and/or ax is important to have to cut the firewood. Closed toe shoes are a must and boots are even better. You need to protect your feet from flying sparks and hot coals. Long-armed heat-safe gloves are extremely important. I use welder’s gloves.

It helps to also have the largest canner you can afford. Canning over an open fire can take longer than using a modern heat source. Collecting the wood, building the fire, and getting it good and hot all take time. I love that I have the biggest canner available (All American 941) because it means that I rarely need to do multiple loads to get my produce canned for the day.


Along with my pressure canner (which is too big to use inside anyway), I have other pots designated for cooking over the fire. They always get black with soot. It has been suggested to me that I rub the outside with dishsoap, making it easier to clean them. If you have shiny pots that are important to you, that’s a good option. But my black pots don’t bother me. I use them outside so frequently that I just don’t want to clean off the soot every time I use them. I just let them be black.

Work Inside as Much as Possibleveggie-prep

I don’t have a beautiful and shaded outdoor kitchen. So, I do as much prep work inside as I can.  The most time consuming part of the canning process can often be washing the produce, chopping it, and putting it into jars. I try to do as much of this inside as possible. It’s much cooler (even without AC) and it requires me to carry much less outside (and then back again). If my recipe allows, I prefer to use the raw pack method and take my already filled jars outside to put directly into the canner.


Have lots of firewood ready!  It’s a pain to have to run around collecting more wood when you are closely watching your fire and processing time. If your heat drops and your pressure gets too low, you will have to start your time again. The best wood to use is pieces that are 2 to 3 inches in diameter.  You want your fire to be able to consume it quickly so it will get hotter immediately.  This is particularly important for longer processing times because you will need to keep feeding your fire.  You don’t want your temperature to drop while your wood is trying to start burning.

Fire Gratecanner-on-fire

We found our grate at a salvage yard and paid less than $10.  We supported it with rebar and placed it on top of two levels of concrete block.  It works well and makes outdoor wood fire canning possible for almost no initial investment, except for the canning supplies themselves.  It was put together in less than an afternoon and we were canning the next day.

Make sure your grate is a good height above your fire.  We have tried a few different heights, but we found the best height is less than 1 foot about the fire coals. Often the flames will lick the bottom of the pot, but that’s okay, especially when the water is coming to a boil.

Boiling Water

Set your pressure canner or pot on the grate and fill it with water before you start the fire. Because my canner is so big, it is much easier to position it when there is no fire to burn me.  I put the lid on and let the water heat as the fire gets started. I always add about a cup of white vinegar to my water. Because I have hard well water, it really helps my jars stay bright and shiny. We like to start our fire and get the water boiling before we are ready to bring the food outside. We usually shoot for about 30 minutes. Give yourself a little more time if you are still practicing your fire building skills.

Time for Canning

Getting the jars in the canner is often the most frustrating part of the process for me. I’ve definitely gotten better at it, but it’s taken some practice. “Smoke gets in your eyes.” The fire is hot. The water is hot. Smoke is venting right where you need to lean over and look in the canner. Jars fall over because you can’t see what you are doing. Did I mention, smoke gets in your eyes?! With practice, I can load my gigantic canner much quicker than I used to.


So, get your jars in and the lid on. At this point, I need to stress following the instructions of your canner. Check the pressure you need for your altitude. Vent the steam according to the manufacturer’s instructions, usually around 10 minutes. Air trapped in the canner means that the temperature will be lower than optimal and your food may not be processed correctly.  So, you want to make sure you vent the steam properly.  After this, put your weight on and start to watch the pressure rise.  How fast the pressure rises will depend on your fire. You may need to add more wood and stir your coals to make it hotter. Start timing your processing time when the pressure gauge registers the correct pressure and the weight gauge jiggles or rocks according to the instructions.

Regulating the Heat

When water bath canning you just want to keep your fire going so that you have a continual boil. But pressure canning requires constant attention with your fire. You don’t want the heat to drop too much. You will lose your pressure and have to start your time again. But you don’t want too much heat because the pressure will continue to build. Too much pressure for too long will cause the water to evaporate inside your canner. You don’t want that! You have to learn to regulate the heat from the fire.

We do this with a piece of sheet metal. We cut it the exact size we needed to completely cover our fire. Once the canner has achieved the right pressure, it will continue to build if you don’t back off the heat. At this point, we place the sheet metal over the fire. By moving it back and forth over the entire processing time, we can regulate the heat of the fire. Sometimes I will leave a very slight flame peaking out from the back. This will hold the right temperature for the longest time. Once the pressure builds too much, I will completely block the fire until the pressure comes down. If the pressure builds too much and it won’t drop quickly, you may need to pour some water on your sheet metal. Just don’t pour it on the fire. You don’t want to douse your coals! I haven’t needed to use water in a while. With a little practice, you can anticipate your pressure building and cover your fire before it rises too much.


If the pressure is beginning to drop, open up the fire completely. The air will get to the coals and the fire will come back to life. Over long processing times (more than 15 to 20 minutes) you will need to add more wood to your fire. Watch your pressure carefully and add wood before it drops. You don’t want to have to start your processing time again!

Watching the fire is a hands on process, but it gets easier with practice. You will begin to anticipate when you need to move the sheet metal and feed your fire. After enough practice, I can now hear the changes in the sound of the pressure weight on my canner and adjust my fire’s heat accordingly.

Ending the Processing Time

The safest practice to “turn off” the heat from your fire is to douse it with water. If you want to save your fire, you will need to move your canner. But for safety reasons, that is not recommended. It is especially difficult with the larger canners.

Leave your canner alone until the pressure comes down naturally. Don’t wiggle the weight, hoping to release the pressure faster. Don’t try to cool it by pouring water on it.  You run the risk of ruining your food because forced cooling can cause loss of liquid from jars, seal failures, and even broken jars. After the canner is depressurized, remove the weight from the vent port and wait 10 minutes before opening the lid.  Always open it away from your face so that steam doesn’t burn you. Don’t be in a hurry.


Pull out your jars carefully with a jar lifter and place them on a towel.  Leave them alone so that they will seal. If I’m canning in the evening, I will often leave them outside overnight. If it is cold outside, let your jars cool in the water with the lid off.  Too severe a change in temperature when you pull out your jars can cause them to burst. I often need to remember this when I am canning deer during the cold weather of deer season.

Are you ready to try it? Canning over a wood fire takes some practice, but I’m so thankful that I have learned the skill. We have an abundance of wood on our off grid homestead, so we have a never-ending supply of fuel. I am confident that if ever the grid really goes down, I can continue to can our food supply. I have no fear that I will ever run out of the fuel that I need to preserve our food.


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