Kristine Kidd

Cabin Life, Cooking, Improving Lives

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The Flavor of Summer
Heirloom Tomato Sauce

At the end of summer, Apple Hill, the fabulous organic farm near our cabin, harvests crate after crate of gorgeous, flavorful heirloom tomatoes in what seems like endless varieties, each one tastier than the one before. And when they have too many, they sell a lug at half price. That is too big a temptation to pass up. I always come home from visits to the farm with more produce than seems possible to consume. Somehow, we gobble up everything. But a 10-pound box of perfectly ripe tomatoes really is too much.


Faced with mounds of tomatoes, I decided to capture the essence of those marvelous fruits by turning them into sauce to enjoy over the winter, when the cold Sierra foothill nights halt fruit and vegetable growth. But, just thinking about spending hours peeling over 10 pounds of tomatoes was defeating. Lucky for me, I had also bought a box of tomatoes for my neighbor Fran, and she saved the day. Fran described her ingenious method of cooking big wedges of unpeeled tomatoes, then pureeing with an immersion blender. She sent the tool home with me so I could try. A little research revealed that the tomato skins add great flavor and nutrition to the sauce, so I went for it.


This sauce is so easy to make, and the results so fantastic, I got my own immersion blender for this year’s crop. While starting with a can of San Marzano tomatoes is easier and quicker, the resulting sauce won’t have the depth of flavor and will be far more acidic than one made with heirlooms. And more than that, you would be missing out on the fragrance of the simmering tomatoes, which turn our cabin into a summer fiesta, and the visuals of a huge pot of the colorful wedges, which are worth several photos.


While using an immersion blender was Fran’s brilliant addition to this recipe, mine was to simmer the rinds of Parmesan cheese along with the tomatoes. They add wonderful richness and even more flavor. I save the rinds all year, in a plastic bag in the fridge or freezer, to add to soups, bean stews, and now to my end of summer tomato sauce.

Heirloom Tomato Sauce

Kristine Kidd
Filled with the taste of summer, I make a couple of batches of this sauce at the end of the season when many farmers are selling large quantities of tomatoes at a discount and friends are overwhelmed with their home garden harvest. After the sauce cools, I spoon it into 1-quart freezer bags and freeze. We enjoy it all winter and spring, while waiting for ripe tomatoes the next summer. Pureeing the cooked tomatoes with an immersion blender eliminates the need to peel them, saving considerable time, plus the skins add good flavor and nutrition. Without an immersion blender, the sauce can also be pureed in batches in a countertop blender. Simmering the rinds of Parmesan cheese in the sauce adds complex richness. Whenever I finish a wedge of Parmesan, I save the rind in a plastic bag in the freezer or fridge, to add to sauces and soups. 
Makes about 14 cups sauce (about 7 1-quart bags, each holding 2 cups sauce)


  • ¼ cup extra-virgin olive oil
  • 2 large onions, roughly chopped
  • 3 sprigs fresh rosemary
  • Coarse kosher salt and freshly ground black pepper
  • 6 ounce can organic tomato paste
  • 10 to 12 pounds heirloom tomatoes, cored, tough spots removed, cut into large wedges
  • 3 to 4 rinds Parmesan cheese or Parmesan and Pecorino Romano
  • Generous handfuls of mixed fresh herbs such as basil, tarragon, thyme, marjoram and/or sage


  • Heat the oil in a heavy large pot over medium-low heat. Add the onions and rosemary. Sprinkle with salt and pepper and sauté until the onions are translucent, stirring frequently, about 12 minutes. 
  • Add the tomato paste and cook and stir for 1-2 minutes. Add as many tomatoes to the pot as will fit. Add the Parmesan rinds. Simmer, adding more tomatoes as the tomatoes settle down and make space. After all the tomatoes have been added, simmer uncovered until the tomatoes are very tender and mostly disintegrate and sauce thickens to thin tomato sauce (it will be thicker when pureed), occasionally stirring and breaking up tomatoes with spoon, about 2 hours. 
  • Place the herbs on a cutting surface. Sprinkle with salt and chop finely. Add to the sauce. Simmer a minute or two to blend flavors. Let the sauce cool slightly. Discard cheese rinds, and rosemary sprigs, and then, puree with an immersion blender. Taste and adjust the salt and pepper. Let cool completely.
  • Mark a 1-quart freezer bag with date and “tomato sauce.” Place the bag in a large mug, glass or widemouthed canning jar and fold the edges over the rim. Spoon in about 2 cups of sauce. Place the filled bag flat on the work surface and coax out any air. Zip closed. Repeat with remaining sauce. Place bags of sauce on a baking sheet and freeze until firm. When frozen, the bags can be stacked. Thaw in the refrigerator before reheating and spooning over freshly cooked pasta.
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