Why do fermented foods taste the way they do?
Fermentation is when bacteria, yeasts or moulds slowly transform food. Along the way they make acids that taste sour, free up savoury compounds that taste of umami, and create new aromas that can be fruity, nutty, cheesy or funky. That is why a fermented food tastes deeper and more complex than what it started as.
What fermentation does to taste
| What the microbes make | What you taste | Examples |
|---|---|---|
| Lactic acid | Clean, mild sourness | yogurt, sauerkraut, kimchi, sourdough |
| Acetic acid | Sharp, vinegary sourness | vinegar, kombucha |
| Free amino acids such as glutamate | Savoury depth (umami) | soy sauce, miso, aged cheese, fish sauce |
| Aroma compounds | Fruity, nutty, cheesy or funky notes | blue cheese, natto, fermented fish |
| Carbon dioxide | A light fizz | kimchi, kombucha, some pickles |
Why fermented food tastes deeper
Many foods hold their savoury compounds locked up in proteins. During fermentation and ageing, those proteins are slowly broken down, and the free compounds give a stronger savoury taste. That is why soy sauce, miso and mature cheese taste far more savoury than soybeans or fresh milk. Read more in What is umami?
Why some fermented foods are an acquired taste
- Strong smells: the same processes that create depth can also create pungent aromas, as in natto or blue cheese.
- Sourness: many people enjoy mild sourness, fewer enjoy it sharp.
- Familiarity: fermented foods are often regional, so what is everyday in one country is challenging in another.
Fermented foods from around the world
- Korea: kimchi, soybean pastes and fermented chilli paste;
- Japan: miso, soy sauce and natto;
- Germany and Eastern Europe: sauerkraut, sour pickles and rye sourdough;
- France, Italy and beyond: hundreds of cheeses and cured sausages;
- Southeast Asia: fish sauce and shrimp paste.
How does it fit your own taste?
Some people seek out the deep, funky flavours of fermentation, others prefer them mild. Taste10 learns your personal taste and predicts how much you will enjoy a food before you try it, with the reason why.
Taste10 is in testing. Want to try it early? Get in touch.
Questions and answers
What does fermented food taste like?
Usually sour, savoury and deeper than the original food, often with fruity, nutty or funky aromas, and sometimes a light fizz.
Why is fermented food sour?
The bacteria that ferment food make acids, mostly lactic acid, which tastes clean and mildly sour, and sometimes acetic acid, which tastes sharper.
Is soy sauce fermented?
Yes. Traditional soy sauce is made by fermenting soybeans and wheat for months, which gives it its deep savoury taste.