No. ALL foods stored on the shelf need processing. It can mold or ferment if you don't process it. The heat processing kills molds and yeasts. Otherwise you have done nothing to actually preserve that food. Sealed up all the molds, yeasts, bacteria in the jars. The lids will pop open if that happens. It only takes a few minutes to process correctly.
I have not done orange juice, but I hear it turns out more like an orange drink in flavor, it loses the natural orange taste.

Agree - orange juice works best frozen. We tried canning it one time and didn't care for the taste at all. It tastes like scorched orange kool-aid.

Grape juice, like all other juices still requires processing and NCHFP gives the instructions and the processing time, BWB for 10 mins. if I recall correctly but you will need to double check that.

Open-kettle canning isn't approved for anything and hasn't been for many years.

Dave

Since your original question had to do with safety, I guess the answer would be "Yes, you could." As grape juice is high-acid, the risks of open kettle pertain more to shelf-life and quality issues than safety per se.

The problem is, as Linda Lou mentioned, you have a high potential for waste, either through mold or fermentation or degradation of quality due to a very weak vacuum and a compromised seal.

Personally, from my perspective grape juice is too much work to deliberately set up conditions which may compromise quality.

Carol

Thanks!