Homemade Ketchup Recipe

By 2023 apprentice Emme Nederbrock

Ketchup over the years has been made in a plethora of different ways. The name originally comes from the Hokkien Chinese word ke-tsiap, meaning fermented fish sauce, and in Europe, the sauce has been recreated with mushrooms, walnuts, oysters, anchovies, and more. The first recipe that involved tomatoes was in 1812, and in 1876, the American Henry J. Heinz created his variation of ketchup. Today, about 97% of American households have a bottle of ketchup! Maybe the traditional Heinz ketchup isn't desirable to you, or doesn't taste good, try this fermented ketchup recipe made right here at Rancho Mastatal! Lots of the ingredients included in the recipe when it comes to spices and sweeteners can be altered due to desired taste, so get creative! This recipe is interpreted from the book “The Farmhouse Culture Guide to Fermenting” by Kathryn Lucas and Shane Peterson. We recommend checking out that book, learning from it, and trying out all their fun, sustainable recipes.

Before starting, there is an importance of making sure you are working in a clean environment. We are relying on natural bacterias to do their work and make a delicious ketchup, so keeping other random, possibly bad bacterias out of the mixture is key. Wash your hands consistently, wash all your produce, and make sure all vessels used for the fermentation have been disinfected properly.

Equipment Needed:

Food processor or blender
Kitchen scale
Pan for sautéing
Fermenting jar (for this recipe are using a 2 liter jar)
A stopper and weight for inside the jar
Pot for cooking down recipe after fermentation

Ingredients:

MAKES 2 LITERS (about 1/2 gallon or 2 quarts) will yield around 1 - 1.5kg of finished ketchup after boiling down

2 kg tomatoes
1 onion
2-4 cm knob of ginger
5 cloves of garlic
Salt (3% of total weight of ingredients above)
Brine (recommended but not a necessary factor)
Sugar (10% of total weight AFTER fermentation, about 200g)
1 Tbsp of cornstarch
Spices to your liking (mustard powder, pepper, smoked paprika, chili powder, etc)

Instructions:

After washing, cut up all tomatoes and remove stems. These tomatoes will be processed in either a food processor or blender so size isn’t too important.
Wash and dice your onion, garlic cloves, and ginger. Add these 3 ingredients to a pan with a little bit of oil and sauté.
Combine your sautéed mixture and your pureed tomatoes and measure weight. Don’t forget to tare your scale with your glass.
Calculate 3% of weight in grams and add that salt in grams. Don’t lose this number! You will need it again after fermenting to calculate how much sugar to add.
Thoroughly combine the salt into mixture and place into the container that will be used for the fermenting! Make sure the sides of the container are clean after adding mixture.
Now is the time to place your follower and weight to keep your new fermented friend submerged! Your follower should fit well into the mouth of your container. Maybe there is a household object that can be disinfected and reused, such as a smaller lid to another container, or a piece of thicker, food safe, plastic you can cut to the desired shape. The weight is extra support for submersion. In our case, we used a disinfected rock. The weight should not cause the follower to sink below the ketchup, but just sit on top and keep everything in place. Worse case scenario, remember this tune, “submerge in brine and all will be fine.”
Close your container and allow to sit in a cool, dry place for about a week, or until desired sourness is acquired. It is possible that kham yeast will grow. Kham yeast is a completely safe, white layer that can sometimes form, even with an airtight lid. You can leave the yeast where it is until the fermentation process is done. When you're ready to finish the recipe, the yeast can either be left in the mixture, or removed.
After about a week, pour your yummy, fermented ketchup into a pot and begin to boil. Stir pretty consistently.
Once in the pot, add your 10% sugar. Maybe a little more or a little less if you prefer more sweet or a more sour ketchup. For our ketchup we used tapa dulce, which is a natural cane sugar, but any sweetener of your choice will do. Support local… and continue to stir!
If the sweetener did not thicken the ketchup enough, adding cornstarch will help. Add your cornstarch to a little bit of cold water and mix together BEFORE adding to your boiling ketchup. Adding the cornstarch straight to a boiling substance will not produce the same result. Keep stirring!
Time to get creative! Add spices of your choice whether that be smoked paprika, pepper, chili powder, and so many more options depending on your palate.
Once you’re done adding seasonings, remove from heat and place your pot in a Bano Maria. This is an ice bath. We do this to cool the temperature of the sauce before we place in into the fridge. Try to stir the ketchup during this process to simultaneously cool the middle and outside.
Final step: Choose your vessel! You can reuse an old ketchup bottle for the squeeze effect, or get fancy by reusing some old glass containers. The cupboard is your oyster.
Place in fridge! This ketchup should last 3-6 months depending on how often the container is opened or left out for dinner purposes. Enjoy!