Supermarket tomato based sauces contain a lot of salt and sugar. I don't understand why people use them when they can make it themselves, make it healthier, tastier and cheaper! I have a challenge for you all: Use this recipe in place of your usual jar for the next 6 months then try to go back to the pre-made stuff. You will never use the jarred stuff again!
As there are no preservatives in this sauce, I do not recommend keeping it. I suggest you use it all immediately. I usually use a garlic Italian seasoning if I can't get a hold of the fresh herbs.