Your pesto recipe sounds similar to the one I use and like. On canning pesto.
Why would anyone want to PICKLE pesto? Which is what you are doing when you get the ph below 4.6 (ANSWER - MSG ID: 205777).
I also, would not water bath pesto. Which calls for, putting the canning jar in a boiling pot of water for the prescribed length of time. Pesto is a low acid food, so thats out.
The open kettle method is dangerous. You fill a jar with hot food, turning it over and hope it seals. The food doesn't get hot enough, long enough.
The jars of pesto in the stores are pressure canned. You can hear the seal breaking and see the lid popping up.
My question is, how long and at what pressure? Could I pressure can it for the length of time for greens? Basil is a leaf like spinach. Greens are pressure canned at 10#s pressure for 70 minutes in pints at 1000 feet or less. I would be using half-pints which use the same time as pints.
If the answer is no. Why? the oil? the cheese? Why? All I have seen recommended is to freeze pesto. Anybody seen a good explanation about not pressure canning pesto?