Sauces, conserves & preserves
Lacto fermented veg – A guide
Lacto fermentation works by pickling or preserving veg in a high-salt, oxygen-free environment. It slows the growth of spoilage bacteria whilst being ideal for beneficial Lactobacillus bacteria to thrive. It converts sugars in the veg into lactic acid; a natural preservative that imparts a distinct savoury depth.
At room temperature the veg will ferment, with the depth and flavour increasing over time. When it is to your taste, this process can be slowed by storing in the fridge. As well as being delicious fermented veg is also teeming with gut-friendly bacteria. You can play around fermenting different veg, below are some examples with flavour pairings.
Cook's notes
Some fermentation methods, such as kimchi or sauerkraut, rely on massaging salt into the veg to draw out the liquid in which it will be submerged, but this process creates a brine instead and allows you to preserve larger more shapely pieces. Whereas the massaging method relies on a percentage of salt relative to the weigh of the veg, this process bases the percentage of salt on the volume of the storage container. You add 2% salt in grams in relation to the millilitre volume of the jar e.g. a 500ml jar will need 10g of salt added to it. It is best to use filtered water as the chlorination of some water supplies can affect the fermentation process.
Ingredients
CARROT, CHILLI & THYME
- 400g carrots – cut into long thin batons
- 2-3 chillies - halved
- small bunch of thyme
- 10g sea salt
- filtered water
- 500ml jar lidded
GREEN BEAN, GARLIC & BAY
- 200-300g green beans – topped and tailed
- 3 garlic cloves, peeled and sliced
- 3 bay leaves
- 10g sea salt
- filtered water
- 500ml lidded jar
RADISH, FENNEL & DILL
- small bunch of radishes - halved
- ½ a fennel bulb – thinly sliced
- ½ red onion, thinly slices
- small bunch of dill
- 6g sea salt
- filtered water
- 300ml lidded jar
Method
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Step 1
Peel, trim, and cut your veg as appropriate.
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Step 2
Add salt to the jar relative to its volume. You want 2% salt in grams – see cook’s notes.
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Step 3
Now pack the jars as tightly as you can with the veg. By wedging them in it helps to keep them from floating up to the top of the jar.
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Step 4
Now fill the jars up with water so the veg is totally submerged. This is important as they need to avoid contact with oxygen. If some veg does float to the top you can place a weight on top to keep it immersed - a cabbage leaf can work, or you can buy small glass weights specifically for this purpose.
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Step 5
Seal the jar and store it at room temperature. It will take a week at least to start a decent fermentation, you can leave it for 2 for a deeper flavour. As you experiment with your taste and preference you could leave it a little longer. Fermentation will depend on temperature, so will be faster in the warmer months. When it is ready you can transfer it to the fridge to slow the fermentation and store it. This isn’t a long-term preserving technique so the veg is best used within the month.
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Step 6
If you are using screw top jars, make sure you don’t screw the lids on too tightly during the fermentation process so that the CO2 has a chance to escape. It can help to loosen them a little every few days to release the gas but avoid opening the jar completely. Clip top jars with rubber seals should release the gas naturally and if you get hooked on fermentation it can be worth investing in jars with specifically designed airlocks on the lids.
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Step 7
You are looking for a pleasant vinegary smell and a tangy, savoury taste with a slight fizz to it. Any signs of mould or spoilage, or smell of rot and it should be discarded.