How long do you need to wait?

Lacto-fermentation is an ancient preservation technique that not only extends the shelf life of vegetables but also enhances their flavour profile and improves nutritional value.

Yes you have done your research, learnt all about the benefits of eating fermented food, realised that home made is best.
You have found yourself some food safe jars with an air lock. Cut up your fresh vegetables so they are all the same size, added the herbs or spices that you love. Bought pure salt, measured how much needs to be added. With a jug of non chlorinated water, it's all combined in your jar, a weight placed on top, so it's all going to stay under the brine. Lid with air lock placed on top. Then the jar is lovingly placed somewhere out of direct sun, where it will be not too hot and not too cold.

A Job well done.

A few days go by, then you ask yourself "When is my ferment ready to eat?"

Taste preferences

You will be given a lot of different answers to that question, it can be confusing at first.
That's because everyone has different tastes, preferring very different flavours and textures. Some genetic differences can affect taste perception. For example, the ability to taste certain bitter compounds varies among populations, influencing their food choices.

• Cultural Identity: Food often serves as a marker of cultural identity. People may develop a preference for their traditional flavors as a way of connecting with their heritage.

• Social Norms: What's considered delicious or disgusting is often culturally determined. Social pressure and norms can influence individual preferences.

• Associations and Memories: Positive or negative associations with certain flavours, often formed in childhood, can last a lifetime and are often culturally shared.

Let's explore the key indicators and some advanced tips to help you master the art of timing your ferments perfectly.

Bubbling Activity

Bubbles are the first sign that fermentation is underway. Here's what to look for:

• Small bubbles: You might see tiny bubbles rising to the surface of the brine, don't worry if you don't, they aren't always visible. The bubbles are a sign that the lactic acid bacteria are actively converting sugars into lactic acid and producing carbon dioxide.

• Fizzing: When you gently tap the side of the jar, you might notice a slight fizzing sound.

• Brine overflow: In very active ferments, you might see some brine overflow from under the lid. This is a good sign of active fermentation.
  Pro Tip: It also tells you that you have over filled the jar, so aim for a little more space above the brine next time.

Changes in Colour and Texture

Visual cues can tell you a lot about the progress of your ferment:

• Colour changes: Most vegetables will become slightly darker or more muted in colour. For example, bright green cucumbers will turn a more olive shade.

• Texture transformation: Vegetables will soften over time, but should still retain some crunch.

• Brine clarity: Initially clear, the brine will become cloudy as fermentation progresses. This is due to the presence of beneficial bacteria and yeast.
  Pro tip: There will be a build up of spent bacteria and yeast sitting on the bottom of the jar, this is normal and how it should be.

Aroma

Your nose can be one of your best tools in determining ferment readiness:

• Pleasant sourness: A good ferment will have a tangy, slightly sour smell. It should be reminiscent of pickles or sauerkraut.

• Complex notes: You might detect hints of garlic, dill, or other spices you've added.

• Warning signs: If you smell anything rotten, overly alcoholic, or reminiscent of nail polish remover, this could indicate an issue with your ferment.

Pro tip: If you aren't using an air lock "Burp" your ferment daily by slightly loosening the lid to release excess gas and take a quick sniff.

Taste Test

Tasting is a reliable way to gauge your ferment's progress:

• When to start tasting:

  • Fast ferments (like cabbage): Start tasting after about 5 days

  • Slower ferments (carrots, green beans): Wait at least a week before tasting

• Flavour profile: Look for a tart, tangy flavour with a complex, slightly sour taste. The vegetable's original flavour should still be present but transformed.

• Salt balance: Initially, the ferment might taste quite salty, but this will mellow over time as the flavours develop.

• Texture: How you intend on eating the vegetables will dictate how long to ferment. If you are after a still firm texture to eat as a crisp salad, 7-8 days might be long enough.
  When making sauerkraut to be cooked into a stew such as a Polish Bigosh ( Hunters Stew) a much longer ferment is wanted, up to 6 weeks are needed to give the well fermented softness and umami flavours so valued in many cultures.
  
  You will hear that you should never open the jar until it's ready, that's because you will loose the build up of carbon dioxide gas which is acting as a preserving layer, as well as introduce unwanted mould, bacteria or yeasts. But when you are starting out you don't know when that will be.
  It makes sense to open it after about five days have a taste, close it back up then leave for a few more days, then taste again. Take note of the flavours and textures and learn how they change with time, it's the only way you will arrive at the timing for the perfect flavour profile you prefer.

Pro tip: Keep a fermentation journal to note how the flavours change over time. This will help you pinpoint your preferred fermentation duration for future batches.

pH Level

For a more scientific approach, you can measure the pH of your ferment:

• Target pH: Aim for a pH of 4.6 or lower. This indicates a safe, well-fermented product.

• Testing methods: Use pH strips or a digital pH meter for accurate readings.

• pH progression:

  • Day 1: pH around 6.0-6.5

  • Day 3-7: pH should drop to around 5.0-5.5

  • Day 7-14: pH should reach 4.6 or lower

Pro tip: You will only need to test the pH in the early stages of your fermenting journey, or occasionally when things don't look so clear cut.

Time and Temperature

While not definitive indicators, time and temperature play crucial roles in fermentation:

• Room temperature fermentation: Most vegetable ferments are ready in 1-4 weeks at 15-24°C,(60-75 F)

• Temperature effects:

  • Warmer temperatures (75-85°F/24-29°C) speed up fermentation, potentially ready in 1 week.

  • Cooler temperatures (50-60°F/10-15°C) slow down fermentation, possibly taking 4-6 weeks

• Seasonal considerations: Your ferments might progress faster in summer and slower in winter due to ambient temperature differences.

Pro tip: Use a temperature strip on your fermentation vessel to monitor temperature fluctuations.

When to Stop Fermentation

Once you're satisfied with the taste and texture of your ferment and its acidic enough it's time to slow down the process;

1. Refrigeration: Move the jar to the refrigerator. This dramatically slows fermentation, preserving the flavour you've achieved.

2. Long-term storage: Properly fermented vegetables can last for months in the refrigerator, if you don't mind a continuation of fermentation they can be left on the shelf without refrigeration.

3. Continued fermentation: Even in the fridge, fermentation will continue very slowly, further developing flavours over time.

Pro tip: The air lock is no longer needed after the ferment is placed in the fridge.

Remember, fermentation is both an art and a science. While these guidelines are helpful, the best way to perfect your ferments is through practice and careful observation. Trust your senses, keep detailed notes, and don't be afraid to experiment to find your perfect ferment! You will find the right balance between taste, texture, acidity and time.

Happy fermenting, and enjoy your probiotic-rich, flavourful creations!