Before refrigeration, our ancestors had to come up with ways to preserve food. One of these ways was fermentation. Fermentation, or culturing, makes use of bacteria and yeasts and their by-products to create an environment that, not only prevents spoilage, but also increases the nutrition of the food that is being fermented.
The microorganisms used for fermenting feed off the natural sugars in the food and, as part of their metabolic process, produce lactic acid. Lactic acid prevents the growth of harmful bacteria as these bacteria do not generally thrive in an acidic environment.
Common examples of lacto-fermented foods and drinks are yoghurt, sauerkraut, kimchi and sourdough bread. If you’ve tried any of these foods, you’ll know the characteristic sourness that they all share. This tart flavour comes about as the probiotic bacteria consume the sugars in the food and produce lactic acid. Generally speaking, the sourer your ferment is, the more probiotics it will contain.
Not only do fermented foods contain a wonderful array of beneficial micro-organisms that help to balance your gut flora and increase your overall health, they also contain higher amounts of many vitamins than the original, non-fermented food.
Remember Captain Cook? His sailors were all dying of scurvy due to lack of vitamin C on their long voyages. They began to bring barrels of sauerkraut on board (oranges spoiled too quickly) and voila – no more scurvy! Sauerkraut contains much higher levels of vitamin C than non-fermented cabbage. This is also true of other fermented foods (and drinks).
Fermenting is not limited to the above examples. Pretty much anything that contains natural sugars can be fermented.
Fermenting is an art as well as a science. No two ferments will ever come out the same – even if you use the same ingredients. This is because fermenting depends upon many factors including:
Fermenting involves the use of live organisms and thus, they will always behave slightly differently depending on their environment.
There are two ways of lacto-fermenting a food – wild fermenting or using a starter culture.
Wild fermenting uses the yeasts and bacteria in the environment, as well as those already on the food. The addition of salt discourages the growth of harmful microorganisms until the beneficial ones are established and start producing lactic acid. With wild fermentation you are never quite sure which micro-organisms are going to take up residence in your jar and so the end result is always interesting and exciting.
When you use a starter culture, you are adding beneficial micro-organisms to your mix to give it a kick-start. This method is a little more controlled as the fermentation process starts sooner and with the bacteria that you introduce – you don’t have to wait for a wild culture to take up residence. A starter culture can be some liquid from a previous batch, whey, kefir – there are many options available depending on what you are fermenting and how you want it to turn out. Different micro-organisms will produce subtle differences in flavour.
Consuming a selection of fermented foods every day has huge health benefits and it is sad that it is no longer a standard part of most people’s diets.
As part of your journey into Real Food, I highly recommend diving into some fermenting fun and discovering the diverse world of new foods and drinks that you can create.
To help you get started, check out some recipes here – more will be added on a regular basis.