Pressure canning on a wood stove?

This month I am focusing on preparedness and asking a few ’what if’ questions. One of those is, what if for some reason we had no electricity and no freezer? Getting a pressure canner seems like it might help to save the meat out of the freezer, and would be handy for other things too, but I am wondering how it would fare on a wood cooking stove?

Are there any dangers of exploding the canner if the stove got too hot? If I can normally regulate the temperature somewhat by sliding the pot to different places on the stove, changing the air intake, or choosing different types of wood, will this be enough to keep things safe?

How does it work with cooling down the canner and waiting for the pressure to drop - is it safe to carefully carry the full, pressurised canner away from the stove to allow it to cool down on the bench? Or is it not safe to move it?

If the stove is having a slow day and taking a long time to bring things to a simmer, is this going to be a problem with the canner? Will it get to pressure eventually even if I can’t get enough heat for a rolling boil?

Looking at my copy of “Pressure Canning for Beginners and Beyond”, it doesn’t say anything about wood stoves, but some things it says to look out for that I think are relevant for wood stoves are:

•Starting the stove off on “high” to begin with - so this would mean on the wood stove I would tinker with air intakes, feed consistently with medium-sized wood that burns well, and basically treat it as if I’m trying to get something boiling or searing. After that, it vents, then I’d put the pressure weights on, and attempt to regulate the stove temperature.

•The weight should be jiggling a bit, but not jiggling non-stop. If it jiggles non-stop, that would mean it’s time to move the canner to a cooler part of the stove, and/or slow down the feeding of wood and air intakes, to cool it down a little.
•“If, at any time, the pressure goes below the recommended amount, you will need to bring the canner back up to pressure and restart the timing. This is why it’s important to have a consistent source of heat. “ So following this, I would be making sure the fire is fed consistently during the whole canning time, and being very observant of how much the weights are jiggling. Would this be the best approach?

Is there anything else I’d need to know about using a pressure canner on a wood cooking stove?

Kate Downham wrote:\Getting a pressure canner seems like it might help to save the meat out of the freezer, and would be handy for other things too, but I am wondering how it would fare on a wood cooking stove?

Great questions. I've wondered most of those myself. What we need is people with experience actually doing pressure canning on wood stoves.

Many have a propane burner set-up for this situation. It needs to be fairly high-powered. (Some are not powerful enough for this purpose.)

But then, what if you couldn't get propane? Then we're back to how to can on a wood stove. I'd like to add one additional question: have you considered what if you want to can in the summer?

I've read that many had an outdoor kitchen. And I suspect that is because it would get awfully hot indoors if you tried to do pressure canning when it is hot. (And in SE Oklahoma, September is still in the 90F temps.)

Here are some videos about canning on wood stoves:





A rocket stove located outside is an option:





Doug and Stacy (YouTube channel) have an outdoor kitchen:

So the "official" answer from the USDA is that pressure canning should not be done on wood stoves because the heat is unstable and hard to regulate. I've never pressure canned on wood so what I'm going to say is not from experience. That being said, if we were in a situation where we had no electricity or access to propane, and we needed to can meat for survival I would absolutely pressure can on a wood stove. To me it's like a "If I'm dying in the wilderness, I'll absolutely eat insects" scenario.

The process for pressure canning is the same regardless of the heat source. So managing the heat is really the only variable. You need the heat high enough to get the canner up to pressure but not so high that it causes too much pressure to build up. Pressure canner manufactures recommended that heat sources not be over 12000btu. If too much pressure builds, modern pressure canners have a quick release valve that will open and steam will pour out. They no longer "explode".

You'll have to watch the canner and fire closely. By the way, it's fine if the canner is a little over pressure but it's not fine if it goes under pressure. If you're using a dial gauge pressure canner at sea level and you're supposed to can something at 11psi and the canner goes up to 13psi, it's fine. But if it goes below 11psi, you'll need to bring it back to 11psi and start the timing over. So you'll want to err on the high side.

You would have to move the canner off and on the heat to regulate it. Under "normal" circumstances, this is would be too much work for me.

I would assume that if the wood stove was slow, for whatever reason, the canner would eventually get to pressure, but the food would be cooking for all that extra time. I would think it would be better to try to speed up the heat than wait hours for the canner to reach pressure.  

A full canner can be moved, so removing it from the heat source is fine, it's just heavy. What you don't want to do is try to cool it faster by putting cold water on it or putting it in a drastically colder environment; doing this can damage the canner.

One thing to note about pressure canning during the summer is that a pressure canner doesn't heat up the house as much as a water bath canning does because the steam is mostly contained within the pressure canner. I live along the Texas Gulf Coast and do most of my canning in the summer because we have a much earlier gardening season than most areas. We've not found it to heat the house up much; although we do have a/c and I know many who live in different climates do not. If I lived in a different climate, I might consider canning in an outdoor kitchen.

If you want to practice your skill of pressure canning on a wood stove, I would start with higher acid foods - like tomatoes that have the extra acid added to them or fruit (many fruits have pressure canning times). With a high acid food you don't have to worry about botulism and the times will be much shorter than when you can meat or legumes.

This is a fun discussion, so much of what we decide to do will be based on our individual circumstances. We just need to be sure that we're using the pressure canner correctly with whatever heat source we choose.

With the question of meat, specifically, I don't know if canning is really the route to go. It sounds like it probably could be done, with enough care and attention, but there are other routes that might make more sense, if preparations are made ahead of time. These aren't necessarily things that can be done at the drop of the grid; attempting to can might be the "easiest" route available in an unexpected, unprepared for SHTF scenario.

Some alternative ideas, in no particular order:
1) In a cold climate, one could put the meat in the woodshed, or some other unheated structure, and let nature freeze it. That's only good if you (a) get winter (b) it is winter and (c) your winter is consistently cold enough to stay below freezing.
2) Build an icehouse and stock it with blocks of ice. Non-electric freezer, as long as you have a source of ice.
3) Build a cold smoker and learn how to smoke and preserve meat. When I was in Spain, years ago, I walked into a sandwich shop and they had whole sides of dried meat just hanging on the back wall behind the counter. I want to learn how to do this...
4) Dry-curing, a-la prociutto - pack the meat in salt and get it good and dry.
5) Raise smaller animals and process them more often - probably the most effective way to store the meat, really, is on the animal. This is where the high-yielding breeds of today work against you - if you can process an animal and use most of the meat in a short window of time, your preservation needs fall dramatically.

Thank you all so much for replying! Meat is important to us, so it’s good to know many ways of preserving it beyond the freezer. Right now I preserve lots of pork with salt every year, but for beef I’ve been relying only on the freezer.

Angi, that is so good to hear that they no longer explode. Your pressure canning book has so many tasty recipes that it is really motivating me to try pressure canning for reasons other than survival!

https://www.amazon.com/Pressure-Canning-Beginners-Step-Step/dp/1645673405/

Benedict Bosco wrote: Raise smaller animals and process them more often - probably the most effective way to store the meat, really, is on the animal. This is where the high-yielding breeds of today work against you - if you can process an animal and use most of the meat in a short window of time, your preservation needs fall dramatically.

This is definitely a good way to go for longer-term survival. It doesn’t get that cold here, but in winter we get fridge-like temperatures rather than non-stop freezing, so can keep sheep and deer hanging outside, beef would be an issue though unless butchered quite young.

I am a trained chef so I can give you an useful bit of advice.
Most restaurants used to have these huge steel stoves. They got turned on in the morning and off in the evening. No way to regulate its temperature.
So chefs use raisers.
We used from one to four to control the heat.
I cannot find a pic of that kind but here is a simple one level riser.

I've pressure canned on a wood stove once and it worked fine - in an outdoor kitchen.  I also sometimes use the rocket stove to bring the canner up to pressure before moving it to a propane stove for the 90 minutes at a constant temp - since if I'm canning I want the rocket stove heating water the whole time anyway.

One question I have.  What are the consequences of having too much heat going into the pressure canner?  I get that the jiggler will jiggle constantly, and that's annoying, but is it going to mess with the jars or the food at all or damage anything?  I suppose it's a matter of degree (pun intended!), but for any normal wood stove temps, do I really have to worry about not letting it get too hot?  

I'd love to only have to be monitoring whether the temp inside the canner is getting below 240.

Philip McGarvey wrote:I've pressure canned on a wood stove once and it worked fine - in an outdoor kitchen.  I also sometimes use the rocket stove to bring the canner up to pressure before moving it to a propane stove for the 90 minutes at a constant temp - since if I'm canning I want the rocket stove heating water the whole time anyway.

One question I have.  What are the consequences of having too much heat going into the pressure canner?  I get that the jiggler will jiggle constantly, and that's annoying, but is it going to mess with the jars or the food at all or damage anything?  I suppose it's a matter of degree (pun intended!), but for any normal wood stove temps, do I really have to worry about not letting it get too hot?  

I'd love to only have to be monitoring whether the temp inside the canner is getting below 240.

The main consequences would be that with the higher the pressure, the more likely it is that the liquid will leak out of the jars (siphon off). The food can also get overcooked and discolored; if you're canning sweet corn it can caramelize and turn brown. The "jiggler" will help keep it at pressure by releasing air, but it is possible to have the heat too high and the jiggler won't be able to keep up. That means that the temperature can get much higher than 240F. That being said, from a safety standpoint, it is safe for the canner to be a little over pressure.

I have now pressure canned using a wood stove several times.

Here are a few observations and tips:

I am doing this on a proper wood cooking stove. I’m not sure how it would work on a stove designed for heating.

To pressure can on a wood cookstove, I just use the same techniques that I use to adjust the temperature for cooking on it - adding more wood, adjusting the air intake, moving the pot around. I wouldn’t recommend canning on a wood stove unless you know how to cook well on one - if you can sear a steak in a pan or bring a pot to a rolling boil and then keep it at that temperature, then you can probably pressure can on it.

Because you can’t just set the heat and expect it to stay the same as you would on an electric or gas stove, it’s important to be nearby when it’s canning to make sure the pressure doesn’t drop because of the temperature getting lower - it’s not the end of the world if it does, it just means you’re supposed to start the timing again from when it gets back up to pressure again, so it will take more time and maybe get a bit overcooked. Right now I’m in the next room and I can hear the weighted gauge moving around, but I wouldn’t want to go outside for long.

I add some extra water just to make sure it doesn’t boil dry - instead of 3 quarts I add 4. So far there’s still been plenty of water left at the end of canning for 90 minutes so this probably isn’t necessary.

To avoid wasting wood, choose your canning time wisely - it’s best to can during a time when you are happy to keep wood burning in the firebox, not when it’s dying down for the night.

The process of bringing it up to pressure involves getting a decent fire going - any fire that would sear a steak or get a pot to a rolling boil is fine. I’ve used all the 3 main types of firewood that we have and they all work well, as long as I use them in the same way that I would for high heat cooking. During this time, the oven will probably heat up quite a bit, so it’s good to time it with bread baking.

I err on the side of putting too much heat into the canner rather than too little for time when it’s under pressure - the weighted gauge seems to be making a constant noise. Usually when I try to move it off the hottest spot on the stove it seems to quieten down a bit too much for my liking. If there is a healthy fire in the firebox I can usually slow the air intake down, keep the pot on the hottest part of the stove, and it stays under pressure nicely without using much wood.

Adding the extra weight to the regulator and relying on the dial instead might give a better idea about what is happening (I have the Australian version of the Presto canner, which has a dial and weights), I might try this sometime while my canner is still fairly new, but as we can’t get them calibrated here I prefer to rely on the weights in general.