This easy sauce recipe transforms heirloom tomatoes into a flavorful, buttery, garlicky sauce with minimal ingredients required. Easy to freeze for a taste of summer all year round.

Bowl of pasta with heirloom tomato sauce

Summer is my favorite food season, and tomatoes are why. They’re the whole reason.

Heirloom tomatoes (also known as heritage tomatoes) are fun to eat raw in salads, where you can really appreciate each one’s unique shape, flavor and color. But if there comes a time when you need to use them up quickly, find a way to preserve them in the freezer, or appreciate them in a way that isn’t raw… a tomato sauce is the obvious thing to do!

Ingredients to make heirloom tomato sauce

What you need to know about making sauce with heirloom tomatoes

The whole thing about heirlooms is their lack of homogeny, so it’s a little bit harder to write a consistent recipe that uses them. We have to be a little flexible and roll with the punches here.

Close up of heirloom tomato sauce in the pan
  • Your sauce may not be the usual red color. Heirlooms can be red, green, brown, pink, yellow or multi colored. Your sauce may not turn out the color you’re used to seeing tomato sauces. Could be lighter and more orange like the one pictured, or even darker with more green or brown hues.
  • And the taste may vary too. Not all heirlooms taste the same, so your sauce will end up a merge of whatever varieties you feature. Some are sweeter, some are more tart.
  • Your cook time may be higher or lower on a given day. Some tomatoes are pulpier than others, some have a bigger core to remove, some are more liquidy… so we could both start with 3 pounds of tomatoes but still end up with a different amount of tomato flesh, or a higher liquid content, and that will affect the cook time and the yield a little bit. I’m going to suggest allowing 1.5-2 hours for this sauce though it could be done in an hour.
Close up forkful of heirloom tomato sauce pasta

Why this butter tomato sauce works

This recipe is inspired by the famous Marcella Hazan Butter Tomato Sauce. It’s the perfect approach to making sauce from heirloom tomatoes. I wanted a recipe that was sure to be tasty even with end of year tomatoes that need a flavor boost, or if you have a few of the more acidic or tart heirlooms in the mix that need neutralising, and butter can do both of those things. Butter makes the texture extra luxurious too.

And it’s really easy! There are so few ingredients, as long as you have the time to let it simmer, it feels pretty achievable.

A bowl of heirloom tomato sauce on pasta

How to prepare the heirloom tomatoes

If you’ve never prepped tomatoes for sauce, let’s take a look at the process. It is not as tricky as it might seem. Especially you’re working with really big tomatoes and only have a few.

First, you will score the tomatoes – this means cutting X shapes into the skins. Then, you want to submerge them in boiling water for a couple of minutes (I like to pour a boiled kettle directly over the tomatoes in a large bowl). After that, the skins will peel away easily starting from the bit you cut into.

You will then chop the tomatoes roughly, discarding the biggest bunches of seeds and the cores.

You have a decision to make with how far you want to go removing the seeds, and it’s really down to personal preference. You can try to remove all of the seeds if you think they’re going to bother you, but that takes more time and means that more juice and liquid will be lost from the tomato while you’re removing those seeds. I personally take out as many seeds as I can easily take out, but lots of seeds do remain and I don’t tend to notice.

And that is most of the work done! The sauce comes together so easily from here:

Those tomatoes just cook down over the course of 1-2 hours, making a perfect sauce every time.

Bowl of angel hair pasta with tomato sauce topping

Butter Heirloom Tomato Sauce

This easy sauce recipe transforms heirloom tomatoes into a flavorful, buttery, garlicky sauce with minimal ingredients required. Easy to freeze for a taste of summer all year round.
5 from 2 ratings

Ingredients

  • 3 lbs (1.5 kg) tomatoes
  • 1 Tbsp, extra virgin olive oil
  • 4 cloves garlic, crushed
  • ½ cup (115 g) butter
  • 1 handful basil, torn
  • Salt, to taste

Instructions 

  • First, we will prepare the heirloom tomatoes. Use a knife to slice an X shape into the skins on each one.
  • Pour boiling water over the tomatoes. Letting them soak in boiling water will make them easy to peel. I like to pour some water directly over the X on the skin.
    Heirloom tomatoes scored
  • Allow to sit in the water for 2-3 minutes before removing them and pouring the water down the sink.
    Heirloom tomatoes soaking
  • Peel off the skins, starting from the area where the skins were cut.
    Peeled heirloom tomato
  • Roughly chop the tomatoes and place in a large bowl. As you chop, take out the big clusters of seeds and the cores. There's no need to remove all of the seeds though.
  • Heat the olive oil over a very low heat, and add the garlic to the pan, allowing to cook for 1-2 minutes until soft and fragrant. Be very careful not to let the garlic burn.
  • Add the chopped tomatoes to the pan and mix to coat them in the garlic.
    Peeled heirloom tomatoes in a pan
  • Add the butter to the pan and mix gently, allow it to melt.
    Adding butter to the sauce
  • Add salt and then you will leave the sauce to simmer. Use a low heat – we want it to gently bubble, but not boil. It will take anywhere from 1 to 2 hours to cook down into the perfect sauce.
    The sauce midway through cooking
  • Check regularly on the sauce, stirring and using a wooden spoon to break up the tomato chunks (though you can leave it with some texture). It will be very watery for a while, but in time will change into a lovely thick sauce.
  • It is ready when it's thick and glossy and and you can see the butter separating from the tomatoes.
    The sauce after thickening
  • Stir in the basil.
  • Serve!

Notes

Nutritional information excludes any pasta – it’s just for the sauce!
Calories: 269kcal, Carbohydrates: 14g, Protein: 3g, Fat: 24g, Saturated Fat: 15g, Polyunsaturated Fat: 1g, Monounsaturated Fat: 6g, Trans Fat: 1g, Cholesterol: 61mg, Sodium: 200mg, Potassium: 827mg, Fiber: 4g, Sugar: 9g, Vitamin A: 3570IU, Vitamin C: 48mg, Calcium: 47mg, Iron: 1mg