Pressure Canning vs Water Bath Canning

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Amish Homesteaders had pm'd me with some questions about pressure canning vs water bath canning, so I had written them back explaining some of their questions. They asked if I would post my answers to them here in public, in case anyone didn't know some of the details between the two:

 

Amish Homesteaders question, in part:

 

Well here is what we need to know- in reading it seems it take a long time between start and finish with a pressure canner (PC’s) compared to water bath? With a water bath canner (WB) you can just start canning – put water in the canner, put food in hot jars, put on the lids, and can. When it is done you take off the lid to the canner, take out the jars and then right away put in new ones and start all over. But every thing we read on PC’s is: put water and jars in canner, heat to almost boiling then put in food, heat PC with gauge off for 10 min., then can for time needed, then let cool down (time?) THEN start over with next batch. Now if we have say 9 quarts of beans to do it seems like a long time to do it this way? And if we have just 3 jars – can we still can them in a PC seems all the info says put in 7 jars? Just trying to see the benefit (other then safety) in using a PC instead of WB when you have a lot to can?

So we need help – is there really that much time between canning when using a PC and how did you do all that corn 7 jars at a time? Seems it would take forever?

 

My Response:

 

Hey there!

 

Let's see if I can explain this right for y'all...

 

First of all, I have 3 canners. 2 All American's, the *papa canner* and the *baby canner*. The papa canner holds 19 quarts and 32 pints in one batch. The baby canner holds 4 quarts and 7 pints in one batch. My 3rd canner was my grandmother's canner and is very very old, although still usable and is more along the standard lines of 7 quarts. I'm able to do the volumes of canning that I do, because I mainly use the papa canner. Doing 19 quarts or 32 pints at one time definitely speeds things up...in fact, I'm seriously considering getting another one so that I can run 2 at a time.

 

Water bath canning is a completely different process than pressure canning. Water bath is simply heating a product, while pressure canning uses heat and pressure to preserve foods.

 

That is why there is a 10 minute recommended venting time with the pressure canner. The air that is trapped inside lowers the temperature obtained for a given pressure and the results are underprocessed foods. Underprocessed foods are more susceptible to bacterias and molds, etc. So when you vent the pc for 10 minutes, you remove that air, and then you process the items for the correct amount of time. When that is accomplished, letting the canner depressurize naturally without any help is also vitally important. Forced cooling can also result in food spoilage. It can cause loss of liquid from jars and cause the jars to seal improperly.

 

If you ever read the evolution of the home canning process, it's a very intriguing account of watching how science evolves. Back in the early 1900's and up until around the 1940's alot of people got sick from strictly water bath processing their foods. As the years went by and they scientifically started to understand how bacterias and harmful agents infected people and foods, the evolution for the safer home canning practices that we use today, began.

 

Botulism spores are difficult to destroy at boiling water bath temperatures, which is why pressure canning is necessary for many foods. Low acid foods should be sterilized at temperatures between 240-250 degrees, which is only attainable in a pc. The time that is needed to destroy bacteria in low acid foods can take anywhere from 20-100 minutes. The exact time depends on the kinds of foods being canned, the way they are packed into jars and the size of the jars. Conversely, the time needed to safely process those same low acid foods in a water bath canner ranges from 7 - 11 hours. When you look at it like that, pressure canning is a much faster process than water bath canning, plus it's a better guarantee that it's safe.

 

The time it takes for a pressure canner to heat up and cool down is in direct coorrelation to the size of your canner. My papa canner takes far longer to heat up and cool down than my baby canner, due to the vast difference of size in the canner. A 7 quart canner for me, is a piece of cake to process in as far as time goes, compared to my 19 quart canner. The trade off is that I get almost 3 times the amount of jars canned at one time so in the long run, I still come ahead.

 

I frequently under pack my pressure canners, i.e. if it holds 19 quarts, I will process foods with only 12 quarts. What I also do alot of times is process different type foods at the same time, if they require the same amount of processing time. Like, I'll can a jar of chicken in the pressure canner along with jars of beef because the processing times and pressures are exactly the same. That affords me to do different type foods and take advantage of extra space and get it all done at the same time. I know that westie uses available space in the canner to can distilled water, which has an indefinite life span, and would be another source of water storage.

 

While I'm an advocate of the All American line of canners, they are not necessary to do safe home canning. I started out on my mom's Sears brand and safely canned in that for years. The reason I initially started with the All American was because they carried the biggest size that enabled me to do the biggest batches at the same time. Being that I'm such a serious canner, the All American's defintely get their use because they're built like tanks. If I couldn't afford them, I would have no qualms about canning in other types like Mirrors and Prestos. I need to get the gauge checked on my grandmother's old pressure canner...I know that thing is about 60 years old, and if it checks out ok, I'll use that too when I'm doing smaller batches of things. Perhaps in your search for a pc, keep in mind the other brands too, at least to start out with. I know that ebay many times has canners at cheap prices so keep your eye out there also.

 

Anyway, I hope this helps answer some of your questions. If I've confused you or if you have any more questions, please feel free to ask me.

 

 

 

[Cathyv]

As you can see I knew if I went to the source I would get the answers!

Thanks Darlene as this has cleared up a lot of the things we were wondering about.

 

Sometimes books are good BUT nothing bets doing it!

[Leia]

Now if we have say 9 quarts of beans to do it seems like a long time to do it this way? And if we have just 3 jars – can we still can them in a PC seems all the info says put in 7 jars?

 

Just wanted to add that in the pressure canner, if you don't have the maximum number of jars (say your canner holds 7 quarts, and you are only canning 5 quarts) you add more water (for my PC, I add 2 1/2 quarts of water for a full batch, 3 quarts for anything less than full).

 

I just got my PC about a year ago, and I LOVE it. We get beef once a year from a friend of ours, and last year our freezer was about half full when the beef was coming in

 

Have fun!

Shawna