C Call, I think you’re a little confused on pH levels. From canning 101: “The way food scientists determine whether something is high or low in acid is by pH. If something has a pH of 4.6 or below, it is deemed high in acid and is safe for water bath canning. If the pH is 4.7 or above, it is considered low in acid.” This salsa registers at 4.0 – which is below 4.6 – so it has an even higher acidity level than is necessary to be safe. In other words, this salsa is well within the limits for safe canning.
The problem with simply heating up the sealed jars is that during normal processing, the goal is to drive all air out of the headspace (the space between the food and the lid). That’s why you only put the lids on finger tight instead of cranking them on as tight as you can. While boiling, the air is forced out, and then the vacuum formed by lack of air sucks down the lid, making a tight seal. No air trapped in the top of the jar = no opportunity for microorganisms that need air to grow to spoil your salsa. If the pH is low enough, botulism (which releases spores in an anaerobic (no oxygen) environment) will also be out of commission. (For more on botulism in canning, read here – https://commonsensehome.com/botulism/.)
The price of jars has gotten ridiculous. I blame the home decorating trend that uses mason jars. Whenever something gets trendy, prices go up. It used to be that I could pick up jars at the local thrift stores for 25 cents each. Now, they want a dollar or more for those same jars. I can buy new at the local hardware store for less than that. It drives me nuts.
Use your jar lifter to place the jars into the canner leaving space in between them. Once jars are all in canner, adjust the water level so it is at least one inch above the jar tops. Add more boiling water if needed so the water level is at least one inch above the jar tops. When adding water, use the hot water from the small pot your lids were in. Pour the water around the jars and not directly onto them.

I have been making salsa like this for years with a couple tweaks I love garlic so I roast everything then chop it up nicely I also add a little garlic salt to brighten up the flavor and if at all possible use home grown veggies especially the tomatoes. People rave over this salsa thanks for this site I love Mexican food especially salsa with lots of peppers in it
During processing, a vacuum is pulled in the headspace of the jar. This vacuum naturally pulls down the lid. (Giving us that distinctive “popping” noise when the jars seal.) On Tattler lids, you manually screw down the lids at the end of processing. This may create a false seal where the air in the headspace has not been properly evacuated, leading to food spoilage. More on that here – https://commonsensehome.com/comparison-of-jarden-and-tattler-lids/
Alright, enough talk. Let’s cook! Well, okay, one last thing before we get down to business. Please note that this salsa roja recipe uses whole, dried chilies which is my absolute preferred and highly recommended way of doing things. If, for whatever reason, you would like to use dried, ground chilies instead, you should add them near the end at step #7 in the recipe below.
Combine all ingredients except cumin, oregano, and cilantro in a large pot and bring to a boil, stirring frequently, then reduce heat and simmer for 10 minutes. Add spices and simmer for another 20 minutes, stirring occasionally. Ladle hot salsa into pint jars, leaving 1/2-inch headspace. Adjust lids and process in a boiling-water canner for 15 minutes at 0–1,000 feet elevation, 20 minutes at 1,001–6,000 feet, and 25 minutes above 6,000 feet.