Canning Roma Tomatoes: Why the Long Processing Time?

If you’ve ever compared canning Roma tomatoes (or any variety actually) to canning salsa, you might have wondered about that long processing time. In this video chat I answer a great question as to why canning times can vary significantly depending on the recipe you are using. She is using Roma tomatoes today but the information is the same for any tomato variety.

If you are here for canning Roma tomato directions… click here for step by step how to can tomatoes, including Roma. Water bath or Pressure Canning are both choices.

Why Does Canning Roma Tomatoes Take So Long Compared to Salsa?

Today’s Canning Chat question is from Kay, who is in Manitoba, Canada. Her question:

I’m going to attempt canning my Romas today.” (Romas, meaning Roma tomatoes.) “This looks like an easy recipe that even I could do. Is it really 85 minutes to process in a water bath? Why so long? I was sure it was only 20 minutes when I did salsa.

Yes, that is the correct processing time for canning Roma tomatoes in a water bath. It does seem long, but that timing come from the National Center for Home Food Preservation.

Here’s why the time is so different:

• Canning Tomatoes in Their Own Juice
  When you’re canning plain Roma tomatoes with no added liquid, you simply pack the tomatoes into the jar, press them down, and let their natural juice fill the space. This method doesn’t add extra acid or liquid, which means the acidity level of the tomatoes alone determines the processing time.
• Salsa Is Different
  Salsa recipes typically include vinegar or another acid, plus ingredients like onions and peppers. That added acid allows for a shorter processing time in a water bath. The acidity level is what makes it safe for processing for a shorter time in a water bath.

Understanding Water Bath Canning Safety

Water bath canning relies on the acidity level of the food to prevent growth of bacteria. Density also affects the processing time. But the acidity level is why salsa can be a shorter time and a plain tomato would be a longer time.

I’ve got more on salsa recipes and knowing if your recipe is appropriate for canning purposes here.

I cannot comment on the safety of your particular salsa recipe, because I don’t know what it is. If you are using a tested recipe with the correct ratio of acid and other ingredients then the processing time will likely be shorter than just canning a plain Roma tomato.

I hope that was helpful. You guys have a wonderful afternoon, and I will see you in the next Canning Chat video. We’ll talk to you later. Bye.

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