TBM and oven canning of fish

[Cootling]

I couldn't believe TBM printed a letter recommending oven canning of fish.  Baaad idea... but don't take my word for it: do your own research.  Every single credible source will tell you the same thing: never, no way, nohow.  Ever.  You can't control temperature adequately and air is a poor conductor of heat, so oven canning may not prevent botulism.  Exploding jars are also a serious risk.

[Blackhawk]

It raised some eyebrows around here too when I saw that.  I could only imagine that if that were practical, why is it not more widespread?

Mom and Dad did tons of canning using a pressure cooker, but using an oven would have been much easier.   I expect there was a valid reason that NO ONE we knew used an oven.

[Shedrock]

I use a pressure cooker only. I don't want to get sick.

I canned a whole doe, minus the backstraps of course, this winter. Very good stuff! Instant meat and gravy over noodles or rice,and great in chili!

I killed the doe with a longbow of course.

[ChuckC]

I did not yet read that article.

A lot also depends on the construct (pH and water activity) of the stuff in the jar.  

Also, I am guessing that the jar lids are not tight during the cook process., mitigating some of the explosions.  

If these jars are then meant to be refrigerated and not shelf stable, that also changes things.

It can be done, and safely, but it is obviously not the recommended method, for all the reasons cited above.

Most folks should probably not try this unless they do some of their own research into what constitutes a proper cook, why, and what are the possible issues, botulism being the biggie.

ChuckC

[Dave Bulla]

My guess would be that the single important factor would come down to temperature duration.  I have not seen the recipe in question but a few points come to mind.

1. Growing up, we canned all our vegetables by the pint or quart and did not own a pressure cooker.  Just the big old blue enamel canning pots and we never had any problems.  Mom canned everything on the stove top.

2. Canning in a water bath such as in my Mom's old enamel pots, wouldn't the temperature be limited to the boiling point of the water?  An oven will go much higher.

3. Wouldn't canning in an oven eliminate that restriction?  You could can at much higher temperatures I would think.  And that makes me think it would allow better sterilization.  Of course, the lids would have to be loose just as when canning by any other method so that expanding gasses could escape and you would probably have to keep an eye on water levels in the jars so it wouldn't cook out.

4. As far as I know, the only difference between canning pot canning and pressure cooker canning is the boil time.  At higher pressure, water boils at a higher temperature so a pressure cooker is faster.  (higher temp = shorter cook time)  But the stove top method has worked fine for a LONG time.  If an oven gets the food to the proper temp for the proper time, how is it any different?

5. After years of surfing the internet and going to all sorts of forums where folks were discussing all sorts of issues, I've come to the conclusion that anytime I hear someone say something "can't be done" the reply should be "have you ever tried it?".

I worked for some time in the food processing/production industry and can tell you that there are a lot of processes done to food in commercial processing plants that would make you gag to see them but the end results are proven safe and accepted throughout the industry.

I love to cook and I've done a very limited amount of home canning (that is, on my own.  I helped my Mom a bunch when I was a kid but she was calling the shots.) but the basic principles are sterilization by heat for a specific time, expansion of air by heating, and sealing of the lid as the air cools.  It's not much more than that.

Of course, I'm certainly no professional cook so this is just my armchair quarterback opinion.  I'll have to go look up some canning info and check on oven canning vs boiling.  Might find something convincing, might not.

[Dave Bulla]

Okay, did a little Googling...

It seems that the general consensus is that it is dangerous due to bottles exploding if not properly sealed.  I'm guessing people tighten the lid down too far and air can not escape.  Here is a comment from one site.

"The immediate danger of oven canning is explosion, because canning jars are not designed to be exposed to prolonged dry heat. If the jars are old, too full, or improperly sealed, they can fail catastrophically, spewing food and glass everywhere. At best, the oven will be filthy and possibly damaged; at worst, oven canning can cause severe burns and cuts from shards of glass."

Several sites recommended a slow cool down period such as just turning the oven off and letting things cool down overnight then taking out in the morning and checking the seal.  I once looked into making glass marbles as a hobby and they all go through a tempering process where they are baked and slowly cooled down to prevent breakage but that was dealing with molten glass.  The concept of controlled rate of cooling might carry over even at the lower canning temperatures.  In real old canning books from Ball and Mason, it does mention oven canning as one method to home can but that was before the lawyers got a hold of them I guess.

Another quote from the same site as above about actual preservation is:

"The dry heat of the oven is also not effective for food preservation. It rarely penetrates all the way to the middle of the canning jar, and there is no way to test the internal temperature without breaking the seal and compromising the food. As a result, bacteria may remain in the food, and it will happily grow and flourish while the food sits on the shelf, potentially causing food borne illness when someone eats the improperly canned food."

Frankly, I do not understand the logic of this.  If it were true and you couldn't get the heat to the center of the food reliably, how the heck do we all manage to survive baking our Thanksgiving turkey or a chuck roast?  It's like I said in my first post, it all comes down to a given temperature for a given time.  Of course, that time has to be sufficient to heat all the way through.  Like DUH!

Okay, I guess I need to go to the book store anyway since I don't have this copy of TBH.  I'm certainly not averse to giving this a try but like many home projects, it obviously requires a bit of common sense.  I think it would work just fine.

But one more recipe I found that might fit here from a site called "Hillbilly Housewife"...

"My mother in law taught me how to oven can deer meat using this method. I put all of my jars (pint sized)into the dishwasher to sterilize. Preheat oven to 350 degrees. Cube deer and cold pack into jars. Add a bit of salt and a few pieces of pork fat to each jar. Always leave ample space at the top of each jar. I take a square of heavy duty aluminum and put it on top of each jar, then secure it in place with the jar ring. (not too tight). Process in oven for 1 hour. While jars are still hot, remove from oven. Using hot pads, remove the rings and replace the foil with a new sterile lid, secure with the jar ring. Leave undisturbed to cool. We have never had an issue with the jars sealing or with spoilage. The meat processed this way is always tender and flavorful. The deer meat is a great substitute in almost any beef recipe. We also have canned pork when we find a great deal on roasts at the local grocery store, minus the extra fat. There is always some kind of risk involved in canning food. There is also always a risk in eating at your favorite fast food place. I will take my chances at home."

[Al Dente]

I hear what everyone is saying, and the info out there is a bit conflicting.  While I can see both sides, the fact of bacteria being present and the risk of exploding glass would lead me away from oven canning.  I've read way too much on exploding Pyrex due to the changing/cheapening of its' manufacturing.  And Pyrex is meant for dry oven heat, and there have several instances where it did in fact explode when it was in the oven or at the time of removal.

In reponse to your query about the Thanksgiving Turkey Dave, a stuffed bird is very dangerous.  Especially stuffing that contains raw eggs or meat products.  By the time the stuffing has cooked thouroughly or reheated through, the bird is overdone.  So naturally, folks pull the bird out when the plastic popper goes up.  Stuffing is not cooked nor has it been reheated to a proper temp for the proper time.  Raw turkey juices flowing into undercooked stuffing means that uneasy feeling  a hours later isn't overeating, it's food poisoning.  Better off cooking the bird and stuffing separate.  To get that turkey flavor into the stuffing, you can do two things.  First, instead of using just chicken broth to moisten it, make an amped up broth by adding turkey wings, onion, carrot, and celery to the broth.  Bring to a boil, then simmer for and hour.  Strain it out and use it.  Second, place the prepared stuffing into a baking dish and place some turkey wings on top and bake.  The turkey flavor just seeps into the stuffing as it cooks.

I'd stick with either pressure canning or stovetop boiling at the recommended times.  Better safe than sorry.  Way too many bugaboos out there that I can't control, the ones I can, I will.

The Ball book and the DK book on preserving are excellent choices to get a wealth of information from.

[JockC]

Let's move on to fermented sausage!

[Dave Bulla]

MMmmmmmmmmmmmm, salami dried in the attic for a couple months....Yummmmm!  

[Joseph]

I canned some deer meat in the oven after seeing the recipe here on this forum.  It was like what was described in TBM.  It worked and it was really good.  Joseph

[Joseph]

I went and brought up the other post from back in 2009 for historical reference