In honor of the Great Tomato Can Jam Round-Up of 2010, today we bring you Garden Vegetable Tomato Sauce. Let me warn you from the get-go: this is not a beginning canner’s recipe. The ratio of non-acidic to acidic ingredients is critical for canning safety, as are strict adherence to the methods (slicing, dicing & measuring) and processing instructions. Also, I’ve tweaked, more than a little bit, a published recipe (Italian-Style Tomato Sauce from the Ball Complete) in order to add some summer garden-glut vegetables, including the controversial-canning-cucurbit, summer squash. Scared yet?

Experienced canners get nervous, and rightly so, when someone starts tweaking an established recipe, especially one dealing with tomatoes, already an on-the-cusp-of-safe-acidity ingredient, and low-acid vegetables such as onions, carrots and garlic.  Add in the verboten-in-the-US squash and home-canners will run for the hills. Botulism City, right? Wrong. I firmly believe that knowledge is power, and that with a thorough understanding of how pH and density affect canning safety, we can make educated substitutions to tested recipes without adversely affecting safety. I also firmly believe that, just because the USDA and the NCHFP (National Center for Home Food Preservation, an excellent resource for home canners) do not have all the time or resources in the world to be testing new, safe zucchini recipes, does not mean that no such recipes exist.  In developing this recipe, I have erred on the side of caution: kept the low-acid ingredients strictly to the same total amount as in the Ball recipe, increased the amount of acid (lemon juice), and paid careful attention to the slicing & dicing of vegetables. Also, I’ve made this for three seasons running now, have enjoyed it all winter long, and survived to tell the tale (not that an N = 1 is much of a scientific basis for proving a recipe’s safety but, it’s better than nothing!). With all of that in mind, I am confident that this recipe is safe for water-bath canning: however, if you have a pressure canner, or lots of freezer space, you can eliminate any concerns with safety by pressure-canning or freezing this sauce.

So, if there is even a question of safety, why would I bother making this sauce? All caveats aside, as I said, I am convinced it is safe: and it is delicious. I love the fact that I can safely make tomato sauce with vegetables that I have on hand, that arrive in the CSA or burst out of the garden. Nothing galls me more than having to go to the store to buy celery when I have 5 lbs of zucchini looming like a green monster on the bottom shelf of the fridge. I also love the fact that I can sneak some summer squash into my husband’s zucchini-o-phobe diet: he doesn’t even notice the “evil weed” in this sauce, even when we eat it plain over pasta. Most of all, I love the flavor of this sauce: the tomatoes, the scallions, the carrots and squash all grew in the same soil, got the same sunshine, enjoyed the same summer rains. It gives the sauce a complexity, and conversely a simplicity, that is hard to describe: if you could pin a taste onto August 17, 2010, this would be it. Come February, I’ll be so thrilled to have a little August on my plate.

Adapted from dozens of tomato sauce recipes in various cookbooks.  Proportions of high-acid to low-acid ingredients determined from Italian-Style Tomato Sauce in the Ball Complete Book of Home Preserving, J. Kingry & L. Devine, eds. 

Not your cup of tomato sauce? Try Tomato Sauce with Fresh Basil or basic Tomato Pureé. For many, many more tomato preserving recipes, check out the August Can Jam round-up over at Tigress in a Pickle.

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Garden Vegetable Tomato Sauce

INGREDIENTS

• 6 cups tomato puree (about 7 to 8 lbs fresh tomatoes)
• 1/4 cup dry white wine
• 1/3 cup scallion, white & light green parts only, thinly sliced (about 2 large scallions)
• 1/3 cup carrot, scrubbed, peeled and grated (about 1 medium carrot)
• 2/3 cup summer squash (I used yellow pattypan and green zucchini), scrubbed, seeded and diced to 1/4-inch or less
• 3 large garlic cloves, minced
• 4 tbsp lemon juice (bottled for consistency of acidity)
• 1 scant tsp sea salt
• 1/2 tsp freshly ground black pepper
• 1/4 tsp chile flakes
• pinch of nutmeg
• 2 tbsp slivered fresh basil

METHODS

1. Prepare tomato pureé according to recipe instructions. Measure 6 cups pureé and set aside.
2. Measure non-acidic ingredients (scallions, carrots, squah, garlic) into a graduated 2-cup measure; make sure to add no more than 1 and 1/2 cups in total to the sauce.
3. In a medium stockpot or Dutch oven, heat the wine over medium heat until it begins to bubble slightly. Add the scallions, carrot, squash and garlic, reduce heat, and sauté over low heat until softened, about 10 minutes. 
4. Add the tomato pureé, lemon juice, salt, pepper, nutmeg and chile flakes. Mix well and return to a boil over high heat.  Reduce the heat and simmer for about 10 minutes (or longer if you would like to further thicken the sauce).  Add the basil and return to a boil over high heat.  Taste and adjust seasonings if necessary.
5. Fill hot, sterilized jars to 1/2-inch headspace and process in a boiling water bath for 35 minutes. 

Yields about 2 and 1/2 pints of a thick, chunky sauce, more if you prefer your sauce thinner. Recipe can easily be doubled.

OPTIONS

1. For safety in canning, you must not increase the total amount of low-acid ingredients (scallions, carrots, squash, garlic, herbs) or decrease the amount of high-acid ingredients (tomatoes, lemon juice).  You may increase the amount of tomatoes/pureé if you wish. Keep the total amount of non-acidic ingredients to 1 and 1/2 cups or less (I find it is easiest to measure them all out together, rather than separately, so if you go over a bit on one ingredient, you’ll make up the difference with another). Pay attention to the directions for slicing/grating, etc.; large chunks of vegetables will affect the ability of heat to penetrate and may adversely affect the safety of your sauce.
2. The USDA’s official position on squash (both summer and winter) is that no squash is good squash for water-bath canning. My interpretation of that rule is that it is based upon canning of the squash alone: there are generally-considered-safe recipes for zucchini marmalade in several cookbooks, including the Ball book. In my opinion, a small dice of summer squash should act no differently in a tomato sauce than a small dice of green bell pepper, and therefore should be a safe substitution; however, I have not pH-tested this sauce, and it is really only my opinion. If you have concerns regarding safety, consider freezing or pressure-canning this sauce instead.
3. This recipe is made without olive oil for safety in canning; to serve, you may wish to add a little olive oil for flavor.
4. Substitute vinegar (at least 5% acidity) for lemon juice and omit the black pepper and nutmeg to make this recipe 100% local.

STORE

Canned, store at cool room temperature, in the dark, for up to 1 year.  Frozen, store for up to 6 months.  Refrigerated, use within 2 weeks.

SEASON

Summer.