Pressure canning without power

Welcome Angi and thanks for the giveaway. I am quite interested in food safety but also from a power out situation. Which always makes me wonder how would we "pressure can" without electricity in some more old fashioned style? Boiling intensely in a big pot and waiting for it to get to 250? I'm not sure. Maybe adding acidic stuff to everything we can so it's unlikely (impossible?) For botulism to occur. Thanks 😊

Seth Japheth wrote:Welcome Angi and thanks for the giveaway. I am quite interested in food safety but also from a power out situation. Which always makes me wonder how would we "pressure can" without electricity in some more old fashioned style? Boiling intensely in a big pot and waiting for it to get to 250? I'm not sure. Maybe adding acidic stuff to everything we can so it's unlikely (impossible?) For botulism to occur. Thanks 😊

Hi Seth - the short answer is you need a pressure canner to "pressure can" safely. Fortunately, a pressure canner doesn't need electricity to run - you can use gas. There are guidelines for using an outdoor gas burner (like a turkey fryer set up) so be sure to find those before using one. It need to be one that doesn't get over 12000 BTU.  Water's boiling point is 212F it cannot get higher than that unless it's under pressure. In an open pot it will boil and evaporate more rapidly with higher heat under it but the water will never get above 212F because it turns into steam.

There's no way to know how much acid you would need to add to a food such as meat to ensure its safety for water bath canning.

I can tell you that prior to 1920 many people used what was called fractional canning, it was a 3 day process - each day they would boil the jars for 1 hour. The theory is that on day one the botulism spores would activate (they need a low acid, anaerobic environment, and 240F to kill them) and make the toxin. The toxin is destroyed at 212 degrees, so the canning on days 2 and 3 is ensure that all the toxin has been destroyed. They would then boil the contents for 10 minutes when they opened the jars to serve. The USDA has not recommended this process in over 100 years.

If being without power (permanently or for long periods of time) is concerning to you, I would suggest that you figure out a way to still be able to pressure can. Just know that a wood fire cannot be used for a pressure canner - the heat is just too unstable.

The pressure canner in this thread is an excellent example of one to use with gas.

There is also a link in the thread to the company which sells the canner:

https://permies.com/t/173692/kitchen/Save-Pressure-Canner

Angi Schneider wrote:

Just know that a wood fire cannot be used for a pressure canner - the heat is just too unstable.

I totally believe that an "open wood fire" would be just too unstable.

However, I was wondering if some of our Rocket Cook Stove users feel that they have enough control to manage a pressure canner burn safely.

This would also be affected by what one's canning - apple sauce depending on the jar size, only needs 10 min at pressure, and my canner says to let the steam vent for 7 min before adding the pressure weight, and then it needs time for the pressure to go up, so a rough estimate would be that one would have to feel they could reliably get their rocket stove to maintain an even temperature for 20 min.

Canning salmon (a popular hobby in my area) is another thing entirely!  (110 min at pressure so over 2 hours burn time?)

This isn't an insignificant issue for me, as my electric stove can't run my pressure canner. Our corn cooker was running too hot at the lowest setting, although I think Hubby's fixed that issue enough that I'd be willing to try again. I know that Wheaton's Lab have been doing some experimenting, and there are some cool looking rocket stoves coming out with images on the web that make me want to put my efforts to a sustainable approach to improving my pressure canning.

It would be cool if there was a ferrous metal pressure cooker so an induction hob could be used.  All the pressure cookers I see for sale are made of aluminum.

Gregory Bruna wrote:It would be cool if there was a ferrous metal pressure cooker so an induction hob could be used.  All the pressure cookers I see for sale are made of aluminum.

Do induction hob's work with stainless steel?  A cast iron pressure cooker filled with jars of food and some water would be *really* heavy.

Jay Angler wrote:

Canning salmon (a popular hobby in my area) is another thing entirely!  (110 min at pressure so over 2 hours burn time?)
.

Yum! I love salmon!
My sole experience with pressure canning was a day helping my dad can tuna. You can bet we didn't do that inside on the stove. We set up outside and used a large propane camp stove with reflector panels around it. We had two pressure canners going- we get one started and when it got up to pressure, we'd start the second one. I don't recall how long they had to go but it was hours. I think we had to do five or six batches. It was pretty fishy smelling.

Hi, I'd have no hesitation at all in using a rocket fire to heat a pressure canner. There's heaps of stuff on the web (https://anamericanhomestead.com/10-tips-for-canning-over-a-wood-fire/
[img]https://anamericanhomestead.com/wp-content/uploads/2014/07/canning1-660x330.jpg[/img] ) - especially if you look up institutional rocket stoves.  We have an All American pressure canner which is well used and I'd have no hesitation in using it in an institutional rocket fire and am confident that the heat could be managed with careful use in quantity and size of fuel.  Here's the link to the Institutional Rocket Stove (https://www.engineeringforchange.org/solutions/product/ies-60-l-cookstove/) currently being produced in Kenya - there are also design and build hints on Youtube if you were to do a search. Or look here.....      https://youtube.com/playlist?list=PLzVw1QCuD6THz6EXRmA1OMw-3FvbDD3qn

[quote=Steve Boyd] We have an All American pressure canner which is well used and I'd have no hesitation in using it in an institutional rocket fire and am confident that the heat could be managed with careful use in quantity and size of fuel.  [/quote]
I have a "non-institutional"rocket stove that I've used to cook my meals for 8 years. I feel I can manage the heat level very well both through fuel selection and placement of the pot. However, during the harvest season when I need to can, it is far too hot to cook indoors, so I use L-type wood burners on my outdoor kitchen. Managing their heat level for water-bath canning is do-able, but the canner is a sooty mess by the time I'm done. I wouldn't put a pressure canner over open flame for that reason, mostly. I have a used pressure canner that I have yet to use for lack of proper burner. I wonder if my old Coleman double burner camp stove would be up to the task. I suspect it would be slow, but able.

I took a wander around youtube today... I found a few folks using open fire or rocket stoves for canning, using All American Canners.

Here is one family in 2014 showing their setup.

Here in 2020, it is mentioned they still do this.


Here is an All American Canner being used on a rocket stove.

The skirt is made from light-gauge corrugated steel sheets that can be purchased from a hardware store.  Cut the length so it extends below the pressure canner about an inch.  I rivoted two pieces of cut sheet together to get the diameter needed to fit around the canner.  The skirt was suspended from the canner handles.

(From the comment section.)


I'm thinking that maybe my thin-walled pressure canner may not stand up to the heat?

Yes, welcome Angi.

This is a very interesting post and something I've wondered about too. Thank you to everyone for the links and suggestions.

Seth Japheth wrote:Welcome Angi and thanks for the giveaway. I am quite interested in food safety but also from a power out situation. Which always makes me wonder how would we "pressure can" without electricity in some more old fashioned style? Boiling intensely in a big pot and waiting for it to get to 250? I'm not sure. Maybe adding acidic stuff to everything we can so it's unlikely (impossible?) For botulism to occur. Thanks 😊

Many that I know will use a Camp Chef or other camp stove when they can so they can do it outside and not heat up the house too much. If you are in a further northern clime, that may not bee too big of an issue.

My mother did it all the time on the old wood and coal stove, cook stove with wood for fuel.  You pressure can exactly the same as on a normal stove in the sense that you bring it up to a particular pressure and hold it for a given length of time.  How the heat was regulated is the only real difference.  You slide the pressure cooker sideways from over the burner area to over the oven area.  The goal was so you could hold it sort of between the 2 areas.  That way if it started falling in pressure you simply moved it to a higher temperature  while you built the fire up and if the pressure was climbing you slid the canner more over the oven area where it was slightly cooler so the fire could burn down a bit.  Feeding the stove to hold it balanced was a bit of an art form specific to the day, the fuel, and the stove you were cooking on.  If you were out over the burner area of the stove you were running too cold as you didn't have the ability to compensate if the pressure started dropping which meant build the fire up.  The goal was keep the stove hot enough you never needed the burner area so you always had it to move to if there was a problem.  The hotter the stove was running the more flexibility you had mostly as you could always move farther from the fire to cool things down a bit.  It was way easier to do on a gas burner as turning a knob is way easier that moving a hot, heavy canner full of jars.  But if you have a full cook top wood stove to work with it can be done.  Mostly you wanted medium consistent size sticks to feed the stove as doing big sticks tended to allow too big a temperature swing and small sticks you were constantly feeding.  By choosing the right size stick Every few minutes you fed it another stick.  The kitchen timer is useful here as a reminder of when to feed the next stick if she was trying to do 2 things at once.  But remember you can NOT regulate the wood fire good enough alone to make this work.  You need to be able to relocate the canner on the stove top to regulate things close enough.  One other trick that helped some was the sticks went in the oven.  So by the time they were burned they were dry on the surface and hot so they got burning faster.

C. Letellier wrote:My mother did it all the time on the old wood and coal stove, cook stove with wood for fuel.  You pressure can exactly the same as on a normal stove in the sense that you bring it up to a particular pressure and hold it for a given length of time.  How the heat was regulated is the only real difference.  You slide the pressure cooker sideways from over the burner area to over the oven area.  The goal was so you could hold it sort of between the 2 areas.  That way if it started falling in pressure you simply moved it to a higher temperature  while you built the fire up and if the pressure was climbing you slid the canner more over the oven area where it was slightly cooler so the fire could burn down a bit.  Feeding the stove to hold it balanced was a bit of an art form specific to the day, the fuel, and the stove you were cooking on.  If you were out over the burner area of the stove you were running too cold as you didn't have the ability to compensate if the pressure started dropping which meant build the fire up.  The goal was keep the stove hot enough you never needed the burner area so you always had it to move to if there was a problem.  The hotter the stove was running the more flexibility you had mostly as you could always move farther from the fire to cool things down a bit.  It was way easier to do on a gas burner as turning a knob is way easier that moving a hot, heavy canner full of jars.  But if you have a full cook top wood stove to work with it can be done.  Mostly you wanted medium consistent size sticks to feed the stove as doing big sticks tended to allow too big a temperature swing and small sticks you were constantly feeding.  By choosing the right size stick Every few minutes you fed it another stick.  The kitchen timer is useful here as a reminder of when to feed the next stick if she was trying to do 2 things at once.  But remember you can NOT regulate the wood fire good enough alone to make this work.  You need to be able to relocate the canner on the stove top to regulate things close enough.  One other trick that helped some was the sticks went in the oven.  So by the time they were burned they were dry on the surface and hot so they got burning faster.

Oh My Goodness! I have a new huge respect for all the people who uses to preserve food on a wood stove like that or still do it that way today. What a skill!

I think the issue with fire is that if you have some steel or iron between the fire and the canner, you'll likely be ok.  

I canned tons of stuff (pressure and water bath) on a maple syrup evaporator.  I just put some 1/4" thick sheets of steel where the syrup pans go and lit the fire.  Just above the fire was "high" and further down the rig was "low".