Why We Long Ferment

The Importance of Long Fermentation

We love fermented foods like Sauerkraut and Kimchi for many reasons including production of: probiotics, postbiotics, other nutrients such as vitamin k and beneficial acids (like amino acids),  breaking down anti-nutrients (plant toxins) and of course, the flavour. Did you know that that the length of time you ferment these foods plays a crucial role in both their taste and nutritional value. While it's tempting to ferment for just a few days,  extending the process to several weeks will significantly improve the benefits.

What is Fermentation?

First it's important to understand what fermentation actually is; In the context of vegetables like sauerkraut and kimchi, fermentation is a process where beneficial bacteria feed on the sugars, fibres and  carbohydrates that make up the vegetables. As they feed they create more beneficial bacteria (probiotics) and the other beneficial nutrients mentioned above.  The acid that's produced through fermentation is also important as, along with salt, this acid helps to preserve the veggies for a long time, keeping them crisp and crunchy.

The Benefits of Long Fermentation

1. Increased Probiotic Content

 A big benefit of long fermentation is the increased production of probiotics.  These are the beneficial bacteria that are essential for gut health. Fermented vegetables are a great source of these probiotics, which help balance the gut microbiome, boosting immunity, mood, fitness, body composition and even contribute to mental health. 

In the early stages of fermentation (the first few days), the bacterial count starts to increase, but the diversity of the probiotic strains is relatively limited. However, as the fermentation process continues, more complex and varied strains of bacteria develop. Studies show that longer fermentation time results in a higher number of probiotics.

2. Increased number of postbiotics + decreased sugar and carbs.

As bacteria feed on sugars, carbs and fibres and multiply, they create byproducts including  vitamins and amino acids.  Any byproduct of probiotic fermentation that is beneficial to our system are known as a postbiotics.  It's probably obvious that the longer fermentation goes on, the more postbiotics are created to to further benefit our gut when we consume them.  

Because the probiotics are feeding on the sugars, carbs and fibres to create more bacteria and postibiotics, this also means that longer fermentation leads to a decrease in sugars, carbs and fibres that naturally exist in the veggies that you're fermenting.  It's a win-win.

3. Reduced Anti-Nutrients

Vegetables naturally contain compounds called anti-nutrients, such as phytates, oxalates, glulcosinolates, lectins and tannins which are kind of toxic to humans, especially in higher quantities. These compounds are part of the plants defence mechanism towards things that want to eat or absorb it.  . These anti-nutrients have a negative effect on our body can make it harder for your body to access the calcium, magnesium, and iron found in vegetables. Fortunately, fermentation breaks down these anti-nutrients.  Again, the longer fermentation goes on the less anti-nutrients remain. This means your body can better absorb the minerals from the fermented vegetables and has less of a struggle dealing with these "toxins".

4. Deeper Flavor and Texture

Taste is another key reason why fermenting for a longer makes a difference. Fermented foods like sauerkraut and kimchi develop complex layers of flavour over time. Initially, after a few days, the fermentation process produces mildly tangy and crisp vegetables, but if you let the vegetables ferment for weeks, they undergo a deep transformation. The taste becomes richer, more tangy, umami and complex.  One of the acids produced as a by-product of fermentation is glutamic acid, which is one of the few ways to get that highly sought after and quite rare  "umami" flavour.

5. Increased Nutritional accessibility

Fermentation doesn’t just preserve food; it enhances its nutritional availability. Vegetables are already healthy, but when you ferment them, their nutrient content becomes even more bioavailable, meaning your body can absorb and use these nutrients more efficiently.

Long fermentation breaks down tough fibres and anti-nutrients, which means your body can access more of the vitamins and minerals that already exist in your food. Sauerkraut and kimchi are particularly high in vitamin C, vitamin K2, and various B vitamins, which become more readily available to us through extended fermentation times.

Additionally, the production of organic acids, like lactic acid, increases over time, which has been shown to have a range of health benefits, including supporting digestion, reducing inflammation, and helping the body detoxify.

The longer the fermentation, the more bioavailable the already existing nutrients become.

How Long Should You Ferment Vegetables?

So, how long is long enough? We recommend fermenting  vegetables for 4+ weeks to maximise the benefits that of the fermented veggies.  How quickly bacteria multiplies does depend on temperature, the environment and the amount of bacteria food available in the veggies you're fermenting.

We have found that at 25 degrees celsius, bacteria quickly multiply for the first 21 - 30  days (depending what veggies are being fermented) before the fermentation slows down and starts to plateau for the next few months.  The sweet spot seems to be roughly 4 weeks, but you can't go too far wrong a few days either side.

Sauerkraut: For a complex, tangy flavour, 3–6 weeks is ideal. Some people even let their sauerkraut ferment for several months!

Kimchi: Kimchi ferments a little faster due to some ingredients that are naturally higher in sugar (carrot, apple and pear for example) and typically hit a sweet spot after 2-4 weeks, but many enthusiasts prefer to let it ferment for a couple of months or more for a more robust flavour profile.

Fermentation happens faster in warmer temperatures and slower in cooler conditions. But here's the rule of thumb: for the first couple of months, longer is better.

Conclusion

Fermenting vegetables like sauerkraut and kimchi for a longer period—several weeks or more—offers a wide range of benefits that can’t be achieved with quick, short fermentations. From increased probiotic content to enhanced flavor, texture, and nutritional value, the benefits of long fermentation are well worth the wait. So, the next time you make a batch of sauerkraut or kimchi, remember: patience pays off! Embrace the slow, transformative process of fermentation, and enjoy the health benefits and rich flavors that come with it.

If you don't have the time to make it yourself, at Gutsy we follow these principles.  You can checkout our fermented veggies here.