The preserves might thicken a little over time, but tomatoes are low in pectin and low in acid, so generally (depending upon other ingredients and whether there was commercial pectin or not) the set will be a little "loose."

You can open the jars, dump the contents into a pan, cook some more, then re-process. That means the jars are clean and hot and you're using fresh lids. In other words, you're starting from scratch on the canning itself.

My problem with re-cooking is you can lose the "deliciousness." Re-cooked preserves can become gummy and also lose freshness of flavor.

I'd be inclined to live with runny and use the current batch to baste pork or chicken, serve as a spoonable condiment with rice or pilaf, similar to Indian chutney, or mix into a jam cake. Or just eat it with toast and live with the drips.

Flavor trumps consistency every time.

Carol

Hmm. I think I agree. If the price of thicker preserves is less flavor, I think I'll just leave them alone. Thanks Carol!