Let’s have a conversation about fermentation. Does that word intimidate you? Bring up thoughts of stinky ingredients? Something that only hipsters and scientists can do? I’d like to break down fermentation and make it a little less daunting. The hope is that a whole new world of flavours will begin to reveal itself to you opening you.
For a little context, here are a bunch of things that you probably consume on a regular/semi-regular basis that are a product of fermentation:
- Black tea
- Any alcoholic beverage
- Aged Cheeses
- Dry aged meats
- Dry cured meats
I think you will agree that most (if not all) of these ingredients are delicious. You might be salivating right now just thinking about them. But why do we find fermented foods so tasty?
To explain this, we need to take a look at what fermentation is, what it does and what it results in. In very simple terms:
“fermentation is the transformation of one ingredient into another by way of a microbe”
– David Zilber
The bacteria changes ingredients, essentially by ‘digesting’ them. This partial ‘digestion’ means that when the food enters our bodies, our digestive system has less work to do to gain the essential nutrition from the foodstuff. Our brain recognises that these foods have had some of the work done already and signals to us that we should eat more of them by recognizing them as delicious, though our senses. It is essentially our brain tricking us into eating more of the things that are good for us.
How Safe is Fermentation
This question is akin to ‘How safe is travelling in a car’? This would make you think of many other factors that would need to be known to answer in an informed way.
- Who is the driver?
- What are the weather conditions?
- Has the car been well maintained?
- How fast is the car travelling?
- Is there a lot of traffic on the road?
- Who are the other drivers?
We can ask similar questions of fermentation.
- Who is starting/monitoring the process?
- What are the environmental conditions?
- Are the conditions being well maintained?
- What is the temperature of the environment?
- What other pathogens (bad bacteria) could be present?
- What is being done to prevent the presence of pathogens?
The answer is that fermentation is an overarching term for a complex range of processes involving different microbes and mediums. But, just like driving, we can do a few things to ensure it is as safe as possible.
David Zilber, formerly the Head of Fermentation at Noma, Copenhagen, describes the role of the fermenter as being the bouncer of a nightclub, only letting in the patrons that fit the requirements to create the desired ambience inside as well as creating a vibe that would only attract the people you want inside. In fermentation, we use the following control points to make fermentations safe; salt, PH, temperature and absence of oxygen. We make use of these and create environments which are perfectly suited to the bacteria we want, and inhospitable for the ones we don’t. For example, cucumber pickles. Pickles are a product of lactic acid fermentation and therefore requires lactic acid bacteria (LAB). The environment we create is saline and absent of oxygen. LAB are halotolerant (salt tolerant) and require an anaerobic environment (in absence of oxygen). They can also tolerate the low PH levels in the resulting ferment. Pathogens such as clostridium botulinum (responsible for botulism) are neither halotolerant or particularly PH tolerant. The controls we employ in the making of pickles and the resulting PH level safeguard against the risk of somebody getting sick.
Lactic Acid Fermentation
Let’s take a closer look at lactic acid fermentation, or lacto fermentation. The bacteria responsible for this process is lactobacillus. These rod-shaped microbes convert sugar into lactic acid and create CO2. The following are a product of lacto fermentation.
- Sourdough (along with yeast)
- Coffee Beans
The purpose of this fermentation would have originally been to prolong the life of the ingredient without refrigeration. In the present day, these foods are still part of mainstream consumption due to the flavours that the fermentation process imparts on those ingredients. Lacto fermentation is very straightforward and requires basic equipment that you probably already have in the kitchen.
Try it for Yourself!
Simple Fermented Hot Sauce
- Handful of Chillies, Stems Removed (you can use any heat level you like, or even a random assortment)
- Garlic cloves, crushed
- Non-iodized salt
- Freshly Washed Jar with screw lid
- Digital scale
- Firstly, weigh the jar you will use for the ferment and take note of it. You will want to select a jar that will accommodate the chillies with as little space at the top as possible.
- Take your chillies and rinse under cold water to remove any surface debris.
- Cut them all in half and add to the jar.
- Add the garlic and fill with the cold water, enough to cover the ingredients.
- Weigh the jar in its entirety. Subtract the weight of the jar and you will be left with your total weight. Let’s call this X.
- To this, we are going to add 2% salt. As aforementioned, this will keep the ferment safe and encourage the lacto bacilles to thrive. To ascertain the amount of salt to add, multiply X by 0.02.
- Add the salt to the jar, scrunch up a clean ziplock bag (or similar) and add on top of the chillies and screw on the lid. The bag will help to keep the chillies submerged. Shake lightly and leave somewhere in plain sight (so you don’t forget about it) at room temperature.
- Each day, slightly open the lid to release the carbon dioxide. This will start after a couple of days.
- After around a week, the ferment will be done. This is when there are no longer any bubbles rising, or gas escaping, when the lid is unscrewed.
- Next, strain the solids out to the mixture while retaining the liquid. It should smell floral, acidic and spicy. Place the solids in a food processor and blend while adding the liquids back into it bit by bit until you find the consistency that you want. You can add a little oil at this point too to give the sauce a shine and lengthening of heat on the palette.
- Transfer to a suitable container and keep refrigerated.
If you enjoyed making this, play around with the flavours next time by adding spices or fruits to create your own signature sauce.
*Note: Any time you are fermenting and the resulting product smells ‘bad’; don’t attempt to eat it. Just discard it. The chances are it won’t taste better than it smells and may carry food borne pathogens. There is always the chance of human error and it could be that the salt content was not right or the jar lid was not clean.