Fermentation

Posted on 19/02/2024

The idea of fermenting at home might seem scary, but it isn’t, it is super easy and is an excellent way to prevent food waste as well as improve your health. Here we will provide you with a bit of an introduction to fermentation, some key rules to follow and a couple of easy recipes to get you started. A video tutorial will follow which will take you through the process of making ferments step by step.

Humans have been fermenting foods for thousands of years, and we continue to do so today although now it is largely done through industrialised processes. It’s very likely that you have eaten some fermented food recently – yoghurt, cheese, olives, miso, kimchi, tempeh, salami are all part of the modern diet and are all the product of fermentation. Before the invention of refrigeration people used all sorts of methods to store food, including fermentation, allowing them to enjoy the bounty of the summer harvests throughout the winter. Fermenting essentially introduces conditions within which good bacteria thrive, making it difficult for bad bacteria to establish, so prolonging the life of the food. Fermenting has the added benefits of improving the flavour of foodstuffs and making nutrients within the ingredients more readily available to our digestive systems so improving their nutritional value. And, as we all now know, the microbes in raw fermented food are key to the maintenance of a healthy gut microbiome – note the use of the term raw, some fermented foods available in the shops have been pasteurised, killing the microbes.  

A quick word on botulism! Botulism is a potentially deadly neurological disease caused by a toxin produced by the bacteria clostridium botulinum. There has been a lot of scaremongering about the likelihood of getting botulism from fermented food. This is absolutely untrue. In fact the conditions created when fermenting are the complete opposite to what botulism spores need to grow. There has not been a single recorded case of botulism caused by consuming fermented foods, so rest assured! That is not to say that ferments can’t go bad, they can, but when they do you will know about it – mould, the stench of rotting cabbage – and you will not want to eat them!

So, what can you ferment? Pretty much any fresh, raw vegetable and fruit! Cabbage is the traditional basis of things like sauerkraut and kimchi, to which things like carrots, apples, radishes, herbs etc can be added. Root vegetables like parsnips and carrots make delicious ferments on their own, and a spicy salsa can be made from tomatoes, peppers, onions and chillis. The possibilities are endless. It is entirely possible to make a delicious ferment using only the slightly sad (not mouldy) looking vegetables at the bottom of the fridge, but it will be infinitely better if these are mixed with something fresh too, aim for 50% fresh to 50% not so fresh. You don’t need any special equipment, just a few jars or containers with lids and something to weight down the ferment – a clean beach pebble, a smaller glass jar or a plastic bag filled with water.

Quick Checklist

Before we get to the recipes, here are a few key rules which we advise you to follow to ensure the best result for any kind of fermentation:

  • Wash vegetables well, and peel carrots, ginger etc if they are not organic.
  • Chop all vegetables to approximately the same size.
  • Chop all vegetables to approximately the same size.
  • Having clean equipment is important – not sterile, do not use sterilising tablets or similar, but wash everything in hot soapy water before you start (including your hands!), and wipe down surfaces. This will help prevent contamination.
  • Glass jars are better than plastic for fermenting, although food grade plastic containers will do if that’s all you have available.
  • If making a brine always use filtered water not tap water straight from the tap as this contains chlorine and other chemicals than can interfere with the fermentation process. Tap water can be used if it is boiled and left to cool for a few hours as this will get rid most of the chemicals.
  • Always leave about 2-3cm of headspace at the top of the jars to allow the ferments to expand otherwise you could end up with a messy overflow! On that note, it is always best to put your jars onto a plate when they are fermenting to catch any liquid that bubbles out.
  • ‘Burp’ your jars daily when they are fermenting to release the carbon dioxide – this is as simple as slightly undoing the jar lid to allow air out.
  • Make sure the vegetables are always submerged below the liquid to keep them in an anaerobic environment and to prevent mould growth.
  • Once you are happy with the flavour of the ferment put it in the fridge. This will slow down the fermentation.
  • Mould is not good! Any mould in your ferment means that it has been contaminated and should be composted.
  • Trust your nose, if it smells off then it probably is!

The Recipes

Sauerkraut

Something about sauerkraut

Ingredients

  • 1 firm headed cabbage (red or white)
  • Sea salt
  • 1 tbsp caraway seeds (other options include cumin seeds, fennel seeds, or grated ginger or horseradish)

Method

  1. Remove a couple of the cabbage leaves and retain.
  2. Finely slice the cabbage, discarding the core.
  3. Weigh the shredded cabbage and add salt at 2% – so for each 100g of cabbage add 2g of salt.
  4. Now it is time to mix and massage the salt into the cabbage to start to draw out the liquids, scrunching and squeezing the cabbage until you can feel it softening and the liquid starting to release. This can take up to 5 minutes.
  5. Once the cabbage has softened and the liquid is starting to flow add in the spice seeds, ginger or horseradish and mix well.
  6. Pack into a jar, pressing each addition down firmly to release more liquid, and pour any liquid remaining in the bowl over the cabbage once you have finished filling the jar, there should be a layer of liquid covering the cabbage.
  7. Using the retained cabbage leaves, cover the top of the shredded cabbage and the add a weight.
  8. Close the jar and leave to ferment for 1-2 weeks.
  9. Taste after a week and once you are happy with it put it in the fridge.

Kimchi 2 ways!

Something about kimchi

Ingredients

    • 1 cabbage – Chinese leaf (Napa) or normal white cabbage

    • Carrots, radish, spring onions etc chopped into sticks or grated

    • Garlic (to taste, I use 4-5 cloves)

    • Fresh ginger, peeled if it isn’t organic (to taste, I use a 3-5cm piece depending on the size of the root)

    • Chilli pepper flakes (to taste) – the traditional Korean chilli pepper is Gochujang which can be ordered online

For long soak method:

    • 1 litre filtered water
    • 40g sea salt

Method

    1. Put the chopped cabbage into a bowl and add the salt, rubbing it into the cabbage until some liquid starts to be released and the cabbage starts to soften. Cover with water and put a plate on top to weight it down and leave to stand for an hour. After an hour drain the cabbage well and proceed as above
    2. Mix the salt into the water until it has dissolved. Remove outer leaves of the cabbage and retain one or two. Remove the tough stem and chop the rest into whatever size you want. Put the cabbage into a bowl and pour over the brine. Weigh the cabbage down with a plate and the leave to soak for 8-10 hours or overnight.
    3. Once the cabbage has soaked for the allotted time drain it well and put it into a bowl with the chopped/grated vegetables, the finely chopped garlic, grated ginger and chilli powder. Mix it well, taste and add more chilli/garlic/ginger if required. Pack it into jars, pressing each addition down firmly to release the liquid – by the time you have finished there should be enough liquid to cover the vegetables. Use the retained cabbage leaves to hold the vegetables in place and add a weight, seal the jar and leave to ferment for 1-2 weeks, tasting after the first week. Once it is tangy enough for your taste put it in the fridge where the fermentation will slow but the flavours will continue developing until you have eaten it all!

For quick method:

    1. 4 tbsp sea salt
    2. Enough filtered water to cover cabbage
    3. Put the chopped cabbage into a bowl and add the salt, rubbing it into the cabbage until some liquid starts to be released and the cabbage starts to soften. Cover with water and put a plate on top to weight it down and leave to stand for an hour. After an hour drain the cabbage well and proceed as above