Martin Nordin’s Sour Tomato Sauce

This salty, sour, and slightly fermented tomato sauce is a unique post-bake drizzle for pizza and much more.

Sour yellow tomato fermented sauce in a glass bottle on a countertop

This standout sauce from none other than Swedish food writer Martin Nordin holds a surreal power over Team Ooni. Ever since hearing about its salty, sour, and slightly fermented flavour (and experiencing it for ourselves in the Chanterelle and Sweet Potato Pizza with Sour Tomato Sauce and Pumpkin Seed Butter), it’s been one of the only sauces we can think about. It’s just not something you come across all that often. Or ever, really.

Martin’s sauce combines yellow tomatoes, celery, and kimchi, the Korean fermented cabbage dish, the latter lending some of its funky bite to the sweet tomatoes. Drizzle on pizza, pasta, salad — you name it, and it will most likely taste amazing. 

If you can't find yellow tomatoes, don’t be afraid to make a substitution with what is available and in season. While your sauce might not have the same dramatic colour as Martin’s, you can use his technique with other types of tomatoes to produce a sauce that still has an excellent and unique flavour.

This recipe calls for the sauce to be stored in sterilised bottles. Sterilising your glass jars and bottles before use involves a few steps, but isn’t something to be ignored! It’s important for food storage and safety and will keep your fermented sauce all the good kinds of funky and none of the bad. You can learn more here

Note: This recipe takes 7 to 10 days to prepare, to make sure to get started well in advance. 

Bio
Martin Nordin's passion for perfecting veggie burgers garnered him a loyal following on Instagram and led to the creation of his cookbook, Green Burgers. He recently published Fire, Smoke, Green: Vegetarian Barbecue, Smoking, and Grilling Recipesand is the creative leader for IKEA Food, where he works to create delicious vegetarian recipes every day

Time
7 to 10 days total time, most of which is passive fermentation

Yield
Makes 1 ½ litres of sauce 

Equipment 


Saucepan
1 large (1½ litres) sterilised canning jar with a rubber seal (such as a Kilner Jar)

Ingredients 


For the kimchi base


500 grams water
20 grams rice flour
100 grams light miso paste
4 shallots, coarsely chopped
2 medium-sized white or yellow carrots, coarsely chopped
100 grams radishes, coarsely chopped
12 grams fresh ginger root
50 grams coarsely chopped garlic
50 grams mild white chilies, e.g. ajì pepper

For the sauce


1 kilogram yellow tomatoes
100 grams celery stalks
24 grams non-iodized salt
200 grams white kimchi base (see below)

Method


For the white kimchi base:
Pour the water and rice flour into a saucepan and bring to a boil, stirring constantly to ensure there are no lumps. Reduce the heat and stir in the miso paste. Simmer for around 5 minutes. Remove the saucepan from the heat and let it cool. Leave the mixture in the refrigerator overnight.

Add the shallots, carrots, radishes, ginger and garlic to a food processor and mix into a fine purée. If it’s a little stiff, add a splash of water.

Pour the rice flour mixture, the vegetable purée and chilies into a glass jar and mix thoroughly. Store in the refrigerator. (If you don’t intend to use it for a while, you can also freeze it.)

For the fermented yellow tomato sauce:
Rinse the tomatoes and cut them in half. Clean the celery and slice it thinly. Put the tomatoes and celery in a bowl and massage in the salt, applying plenty of pressure to the tomatoes so they release liquid. Leave at room temperature for at least one hour, occasionally stirring and applying pressure.

Pour the kimchi base into the bowl and mix gently using your hands.

Pour the mixture into the jar, leaving an inch or so (2 to 3 centimetres) of air at the top. Fill a plastic bag with some water, knot the bag and add it on top as a weight. (You’ll understand why in a few days.) Close the lid and seal tightly. Place the jar on a plate and, ideally, stand it inside a plastic bag since it will likely eject some liquid.(If you do this, make sure you don’t seal the bag at the top.) Leave the jar to stand at room temperature for 7-10 days, depending on how sour you want the sauce to turn out.

Move the jar to the refrigerator. Remove it after a few days, pour it into a bowl and blend until smooth. Strain the sauce and pour into sterilised bottles, then store in the refrigerator until ready to use.