Are you asking how the recipe can be made safely so that you can make them? If so then that is easy to do. Simply change the vinegar to water ratio to minimum of 1:1 and process in a BWB for 10 mins.

Or are you hoping to convince someone else in the family that using this recipe is unsafe? That ISN'T easy to do no matter what we or you might say to them.

We run into "secret family recipes" here all the time but very seldom is the user inclined to accept any changes to it and their reason is the same as you stated - "no one has died".

Instead they usually want to defend it and argue for why it is perfectly safe even though, in this case, so-called 'oven-processing' has not been considered safe for many decades. So unfortunately the effort and time we spend explaining why it is unsafe is usually wasted.

So what is the goal?

Dave

My hope was for an argument and recipe that would convince a bunch to 60 - 80 year old farm women that they way they've always done it is no longer acceptable, and in fact is downright dangerous. I guess I'll see what I can come up with on my own.

Steve

Well here are some points you can try and I do wish you luck

Vinegar was a great deal stronger in the old days - often as much as 20%. Now only 5% is available so the lowest ratio of water to vinegar that is approved (except for a couple of tested exceptions) is 1:1 - same amount of vinegar as water. And that is the MINIMUM ratio. 2:1 vinegar to water is the common standard.

Along with the cukes, fresh dill and garlic are both low-acid (alkaline) foods so adding them further reduces the acidity of the mix and increases the need for more added acid. You can print out this page on proper pickling safety from NCHFP for them.

Oven canning does not process the food in anyway, it only causes the jars to seal. Even 60 years ago "oven-canning" was not an approved process. Per the History of Home Canning at NCHFP, pickles were supposed to be water-bathed canned even back in the early 1900's so Aunt Mildred was out of touch with the canning guidelines even way back then.

To safely process the food in the jars of food must be emersed totally in water and the water surrounding them brought to 212 degrees (boiling) for a prescribed period. From NCHFP:

Is it safe to process food in the oven?
No. This can be dangerous because the temperature will vary according to the accuracy of oven regulators and circulation of heat. Dry heat is very slow in penetrating into jars of food. Also, jars explode easily in the oven.

Further the jar manufacturers strongly recommend against so-called "oven canning". One need only look at today's jars to see the difference in the thickness of the glass. There literally is no comparison.

Then, aside from botulism, there is listeria - a bacteria which can grow even in an acidic environment and which was not even known to exist 60 years ago (or even 15).

Lastly is the studies which show that acidity levels do not remain stable during shelf storage. They gradually rise into the alkaline zone. This is especially true with pickled cukes as all the water that was in the cucumbers is drawn out of them by the salt and it dilutes the vinegar in the jar even more.

Hope some of this helps. Point them to the recognized authority on safe home food preservation - NCHFP for lots of info.

Dave

Dave, thanks for the help. I may be able to convince these old gals yet!!

Steve

Ok, I basically am saying the same as Dave did...
Remind them that cucumbers are low acid vegetables and since their old recipe doesn't have enough acid added with todays vinegar that botulism is also possible, not just listeria. Be sure that the vinegar you buy now is at least 5 % acidity. Some cheap ones and rice vinegars are only 4 % and would be unsafe to use.
Processing correctly will destroy enzymes, molds, and yeasts, plus cause a true vacuum seal. The oven will not heat them hot enough to do any of the things. Besides the oven can cause jars to explode !! They are not meant for that kind of heat from an oven. Even the jar mfgs. will tell you that.
You can tell them that a Master Food Preserver/Food Safety Advisor from a University Extension Office told you these things.

yes some old time vinegars were stronger than 5% so could take more water. those days are now long gone.