Sauce – Sanitizing bottles/jars for homemade sauce

Since cooking the pasta in salted water is essential, and switching to fresh water or whatever is a PITA, I'd just use less water and thicken with something else.

The standard ratio for salting pasta water is 1:10:100 - 1 litre of water for 10g salt and 100g pasta - perhaps you're over-salting the water?

It sounds reasonable: the large quantity of vinegar will acidify the pickles, preventing the growth of botulism.

The processing step is mostly to seal the jars; the vinegar is the real preservation agent.

Still, I would feel better if The Kitchn had cited the source of the recipe, as you only want to use recipes that come from a trusted and qualified source.