I have seen those methods too, but have read that it really is not safe and that you can get a false seal. Why take the chance? I wouldn't. I use the water bath method for my tomatoes and also make spaghetti sauce and freeze it, when I don't have enough maters to can.

Hi Panos - The harvest forum here is the canning and preserving forum and I linked it for you below for more info.

The inverting method of jar sealing has not been considered safe to do per the US guidelines for several decades. But we understand that it is still practiced in other parts of the world. That is their choice and their risk to take. Unfortunately they may not have access to all the research done on this issue in this country.

The method you describe is well documented to have a much higher percentage of seal failures, spoiled produce, and bacterial contamination. So proper acidification of tomatoes and proper processing of the jars either with BWB or pressure canning has been recommended in this country since the early 1960's. In 1976 that recommendation was increased to a "requirement for safe canning" of tomato products.

So it is your choice. Keeping in mind that botulism has no odor or taste and no way to detect its presence, only you can determine how much of a risk level you are willing to accept. With proper processing the risk is eliminated.

The current instructions for canning tomatoes - including sauce - can be found at the website of the National Center for Home Food Preservation (NCHFP).

BWB processing of tomato sauce requires 35-40 min depending on jar size and the pressure canning time is 15-20 min with the pressure adjusted for altitude.

Hope this helps.

Dave

Here is a link that might be useful: Harvest forum

That's called open kettle canning and is not approved by the USDA. You don't need any special equipment to water bath can - as long as you have the jars and a deep stockpot. You will need to add acid (wine, vinegar, lemon juice, citric acid) and if making sauce rather than just canning tomatoes, best to use a tested recipe so that you don't end up with too many low-acid veggies (peppers, mushrooms, onions), fresh herbs, or oil.

There is a Harvest forum on GW, but best place to start is here:

Here is a link that might be useful: National Center for Home Food Preservation

Dave beat me to it!

For home use and canning, USDA rules is not enforced.
Here is what I am saying: If your jar is disinfected (in boiling water or 300F oven), and you have boiled the sauce; Then you fill the jar, tighten the lid, then place them upside down, ...how the heck bacteria is going to get into it ?
One more thing: When you want to use the sauce you boil it again !!! If you cannot kill a bacterium by boiling, forget about canning and eating tomato sauce.

For home use and canning, USDA rules is not enforced.

If you mean there are no canning police who will come and arrest you then yes, they are not enforced. However liability, not to mention responsibility, does attach to any home canned foods that are shared with others.

fill the jar, tighten the lid, then place them upside down, ...how the heck bacteria is going to get into it ?

It doesn't have to "get in". It is already in there. So is the air still trapped in the jar that allows the bacteria in the jar to continue to grow, reproduce, and produce toxins.

The only foods where inversion sealing is still commonly practiced anywhere is with highly acidic foods - fruit jams and jellies, canned fruits, and brined pickles. Tomatoes do not quality as highly acidic foods since they are borderline pH at 4.5-4.8.

If you cannot kill a bacterium by boiling, forget about canning and eating tomato sauce.

There are many bacteria, including c.botulinum, that cannot be killed by boiling but that doesn't mean the food cannot be canned. Those bacteria are killed only by irradiation (which isn't possible at home) or by high pressure temps in excess of 240 degrees for a period of time determined by the density of the food in question. Alternatively they are packed in an highly acidic medium which prevents the bacteria from reproducing in the jar. Thus the requirement to add additional acid to tomatoes when canning them.

None of this is new info. It dates from research begun back in the 1950's. And it is all discussed in great detail on the Harvest forum for those interested. But I would suggest some research into all the science behind the canning guidelines before sharing such mis-leading information with others. It does them a dis-service otherwise.

Dave