Select Page



Lactofermentation, also known as lactic acid fermentation, is a natural process in which microorganisms, primarily lactic acid bacteria, convert sugars into lactic acid. This process is commonly used to preserve and transform various foods, especially vegetables and fruits. The lactic acid produced during lactofermentation acts as a natural preservative, inhibiting the growth of harmful bacteria and helping to extend the shelf life of the fermented foods.

Here’s how the lactofermentation process generally works

  1. Preparation: Raw vegetables or fruits are cleaned, sliced, shredded, or otherwise prepared for fermentation. They are often mixed with salt, which helps draw out moisture from the vegetables and creates an environment that is conducive to the growth of lactic acid bacteria while inhibiting the growth of undesirable microorganisms.
  2. Fermentation: The vegetables or fruits are packed into a container, such as a jar or a fermentation crock, along with any desired herbs, spices, or flavorings. As the vegetables release their natural juices and combine with the added salt, a brine is formed. This brine creates an anaerobic (oxygen-free) environment, which is ideal for the growth of lactic acid bacteria.
  3. Lactic Acid Production: Lactic acid bacteria naturally present on the surfaces of the vegetables or introduced through the environment start to multiply in the brine. These bacteria convert the sugars present in the vegetables into lactic acid through a process called anaerobic respiration. This lactic acid not only preserves the vegetables by creating an acidic environment but also imparts the characteristic tangy flavor associated with fermented foods.
  4. Maturation: The fermentation process typically takes several days to a few weeks, depending on factors such as the type of vegetables, ambient temperature, and desired flavor. During this time, the lactic acid bacteria continue to grow and produce lactic acid, gradually lowering the pH of the brine.
  5. Flavor Development: As the lactic acid concentration increases, the flavor of the vegetables changes from raw to tangy and complex. The texture of the vegetables also changes, becoming softer and more tender.
  6. Storage: Once the desired level of fermentation is achieved, the fermented vegetables are usually transferred to cold storage, such as a refrigerator or a cool cellar. The low temperature slows down the fermentation process and helps maintain the quality of the fermented product.

Lactofermentation is responsible for the creation of various fermented foods, such as sauerkraut, kimchi, pickles, and certain types of relishes. These foods not only have an extended shelf life but also offer potential health benefits due to the presence of beneficial bacteria and the breakdown of nutrients that can make them more bioavailable.

Lactofermenting tomatoes

Lactofermenting tomatoes is a unique and flavorful way to preserve and enjoy their taste. Here’s a basic guide to lactofermenting tomatoes:


  • Ripe tomatoes
  • Non-chlorinated water (filtered or bottled water), leave 30min to 1h in a bowl to let chorine evaporate
  • Salt (non-iodized, preferably sea salt or kosher salt),
  • Optional: Herbs, spices, garlic, or other flavorings


  • Glass jar or fermentation crock
  • Weight or fermenting weights
  • Lid or cover
  • Bowl or plate to catch any overflow during fermentation


  1. Prepare the Tomatoes:
    • Wash the tomatoes thoroughly and remove any stems or blemishes.
    • Depending on the size, you can leave smaller tomatoes whole or cut larger ones into halves or quarters.
  2. Create the Brine:
    • Prepare a brine solution by dissolving salt in non-chlorinated water. A common ratio is about 2 tablespoons of salt per quart (1 liter) of water, but you can adjust the saltiness to your preference. Recommended is 10Gr per kg of vegetables or 1000ml x 0.02 (aka 2%) = 20g (my 2L jar require 40Gr Salt)
  3. Pack the Jar:
    • Place the tomatoes in the glass jar or fermentation crock, leaving some space at the top.
    • If desired, add flavorings such as garlic cloves, herbs, or spices between the tomatoes.
  4. Add the Brine:
    • Pour the brine over the tomatoes, ensuring they are fully submerged. Leave about an inch of headspace at the top to prevent overflow during fermentation.
  5. Use Weights:
    • Place a weight or fermenting weights on top of the tomatoes to keep them submerged under the brine. This helps prevent mold growth.
  6. Cover the Jar:
    • Cover the jar with a lid, or if you’re using a fermentation crock, follow the manufacturer’s instructions for sealing.
  7. Fermentation:
    • Place the jar in a cool, dark place at room temperature (ideally around 65-75°F or 18-24°C).
    • Check the jar daily for the first few days to make sure the tomatoes are submerged and to release any built-up gas. Press down on the weight if necessary.
    • You will start to see bubbles and notice a change in the texture and color of the tomatoes. The fermentation process usually takes around 1 to 2 weeks, but you can let it ferment longer for a more tangy flavor.
  8. Taste and Store:
    • Taste the tomatoes after the initial fermentation period and decide if they have reached your desired level of tanginess.
    • Once you’re satisfied with the flavor, remove the weight and cover the jar with a regular lid.
    • Transfer the jar to cold storage, such as a refrigerator, to slow down the fermentation process.
  9. Enjoy:
    • Lactofermented tomatoes can be used in salads, sandwiches, wraps, or as a flavorful addition to various dishes.

Remember that lactofermentation is an art as well as a science, and the results can vary based on factors like temperature, salt content, and personal taste preferences. Experimenting with different herbs, spices, and fermentation times can help you find the perfect flavor profile for your lactofermented tomatoes.