the science of fermentation

Throughout this blog, I’ll touch on some of the concepts and science behind fermentation.  This will help you get a basic understanding of the principles.  I’ll continue touching on the science throughout the website. To get an in depth understanding, I could not recommend The Art of Fermentation more highly.  Written by Sandor Katz, it describes the history but also the mechanisms for fermentation.  It traces the earliest example of yogurt making in camel stomachs through to the work being done in restaurants like Noma.

Say hello to my little friend(s)
Ultimately all fermentation takes place thanks to the bacteria that exists alongside us.  On any raw food, there are many types of bacteria present.  To make sourdough, add flour and water and after a week you’ll have a bubbly starter.  You can turboboost this by adding grapes which come with other bacteria. An increasingly trendy development is wild brewing.  This makes use of the natural yeast around us to make alcohol, rather than relying on brewers yeast.

However, to get the fermentation we want, we need to create the right environment.  If you left a cabbage for a few weeks, it wouldn’t just turn into sauerkraut.  The bad bacteria on the cabbage will out compete the good bacteria and it would go off.  However, add enough salt and create an anaerobic environment we make it impossible for moulds to grow.  This instead will allow the lactic acid bacteria to form and, given time, turn into sauerkraut.  This process is also true of lacto-fermented citrus fruits.

So how is yogurt different to kombucha?
In contrast, to make kombucha or apple cider vinegar, oxygen is required.  So, air must be able to circulate in the fermenting environment. Jun tea requires cooler temperatures as does mesophilic yogurt (Langfil, Viili or Piima).  Whilst thermophilic yogurt (Greek Yogurt and Skyr) require much warmer temperatures – around 42 celsius.

In its most basic form therefore, the science of fermentation is knowing and understanding the type of environment you need; and then creating and maintaining it.

But why are fermented foods so good for you?