I've been fermenting chillies for a while now — it's become a reliable part of how I preserve the harvest and build flavour over time. But until recently, all of my ferments have been chilli-based. This is my first proper vegetable ferment, and I started with baby pepinos because I had a handful sitting around and curiosity got the better of me.

Fermentation is different from pickling. Last year, I made quick-pickled pepinos with apple cider vinegar — sharp, fast, ready in a day. This is slower, quieter, and more interesting. Lacto fermentation relies on naturally occurring bacteria to preserve the pepinos, creating tang, complexity, and that characteristic cloudy brine. It's alive in a way pickling isn't.

I started this batch on 15 February. Today is 20 February, so we're five days in. The brine is cloudy (that's normal), the pepinos are still submerged under the fermentation weight, and the flavour is sharp — possibly too sharp at this stage. The room temperature has been fluctuating between 14–20°C, which is cooler than ideal, so fermentation is moving slowly. The sourness is developing faster than the depth, which explains the sharpness. I'll give it another day or two before deciding whether to move it to the fridge or let it continue.

Why Ferment Pepinos?

Pepinos — also known as baby cucumbers or gherkins — are small, mild cucumbers perfect for fermenting whole.

Baby pepinos are mild, slightly sweet, and crunchy — exactly the kind of vegetable that benefits from fermentation. The process preserves them, adds complexity, and turns them into something you'd actually reach for: sliced into salads, served alongside sandwiches, or eaten straight from the jar as a snack.

Fermentation also keeps them crunchy in a way that vinegar pickling doesn't always manage. The texture stays firm, the flavour develops over days, and the end result is genuinely interesting rather than just "preserved cucumber."

What You'll Need

This is a small batch — designed for one 750ml jar with a fermentation weight. I used eight baby pepinos because that's what I had. If you've got ten, use ten. The recipe scales easily.

Ingredients

• 8–10 baby pepinos, washed
• 1–2 cloves garlic, peeled and lightly crushed
• 1 tsp black peppercorns
• 1–2 sprigs fresh dill (or a pinch of dill seeds)
• 1 tsp mustard seeds (optional, but recommended)
• 250 ml filtered water
• Dissolve 1½ tsp of non-iodised sea salt in 250 ml of filtered water.

Equipment

• 750ml glass jar with a wide mouth
• Fermentation weight (essential — pepinos float)
• Clean cloth or loose-fitting lid

How to Ferment Baby Pepinos

1. Trim the Ends

Cut a small slice from the blossom end of each pepino (the end opposite the stem). This prevents softening during fermentation and helps keep them crisp.

2. Make the Brine

Dissolve 1½ tsp of non-iodised sea salt in 250 ml of filtered water. Stir until the salt is fully dissolved. Don't use iodised salt — it can interfere with fermentation.

3. Pack the Jar

Place the garlic, dill, peppercorns, and mustard seeds at the bottom of the jar. Stand the baby pepinos upright, packing them as tightly as possible without squashing. They should be snug enough that they don't move around easily.

4. Add the Brine

Pour the brine over the pepinos until they're fully submerged. Leave about 2 cm of space at the top of the jar to allow for expansion and gas release.

5. Weight Down

This is non-negotiable: baby pepinos float. Use a fermentation weight, a small glass, or a clean stone to keep them submerged. If they bob above the brine, they'll develop mould.

6. Cover Loosely

Cover the jar with a lid that's not fully tightened, or use a clean cloth secured with a rubber band. Fermentation produces gas, and it needs to escape. A tightly sealed jar can build pressure or even crack.

7. Ferment

Leave the jar at room temperature, ideally between 18–22°C. Check it daily: taste for sourness, ensure the pepinos stay submerged, and skim off any surface scum if it appears (it's harmless, just unappealing).

8. Timing

Small pepinos usually take 3–7 days to ferment, depending on temperature. In a cooler room (like mine), it will take longer. Taste them regularly — once they're pleasantly tangy and the sharpness has mellowed into complexity, tighten the lid and transfer to the fridge. Fermentation slows dramatically in the cold.

9. Store and Enjoy

Fermented pepinos keep in the fridge for 2–4 weeks, sometimes longer. Eat them straight, slice them into salads, or serve them with sandwiches. They're crunchy, tangy, and far more interesting than anything you'd buy in a jar.

Notes from Day Five

The brine is cloudy — that's completely normal and a sign that lacto fermentation is happening. The cloudiness comes from the bacteria doing their work.

The flavour is sharp at this stage, possibly too sharp. This is likely because the room temperature has been on the cooler side (14–20°C), which slows fermentation. The sourness develops faster than the depth and complexity, so the balance isn't quite there yet. I'll taste again tomorrow and decide whether to let it continue or move it to the fridge.

The pepinos are staying submerged under the fermentation weight, which is essential. Without it, they'd float to the surface and risk developing mould.

Pro Tips for Fermenting Pepinos

• Don't skip the fermentation weight. Baby pepinos are buoyant. If they're not fully submerged, they'll spoil.
• Taste often. Fermentation speed varies with temperature and the specific bacteria in your environment. The only way to know when they're ready is to try them.
• Cloudy brine is good. Clear brine usually means nothing's happening. Cloudy brine means active fermentation.
• Add chilli or horseradish leaves if you want extra flavour and crispness. They're traditional additions in lacto fermentation.
• Temperature matters. Warmer rooms ferment faster. Cooler rooms take longer and can produce sharper, less balanced flavours early on.

Fermented vs Pickled: What's the Difference?

If you've made my quick-pickled pepinos, you'll notice the difference immediately. Pickled pepinos are fast, sharp, and vinegar-forward. They're ready in a day and taste exactly like vinegar-preserved vegetables.

Fermented pepinos are slower, more complex, and alive. The tang comes from lactic acid produced by bacteria, not from added vinegar. The flavour is rounder, the texture stays firmer, and the process feels more like collaboration than preservation.

Both have their place. Pickled pepinos are brilliant when you need something fast. Fermented pepinos are worth the wait.

What's Next?

This is my first non-chilli ferment, and I'm already thinking about what else to try. Carrots, radishes, green beans — all of them would work well with this method. The principles are the same: clean jar, simple brine, fermentation weight, patience.

For now, I'll let these pepinos finish developing and see how they turn out. If the sharpness mellows and the complexity comes through, they'll be exactly what I was hoping for. If not, I'll adjust the next batch — warmer room, longer fermentation, different aromatics.

That's the beauty of small-batch fermentation. Low stakes, high learning, and always something to try next.

Keep fermenting — more live cultures, pickles, and preserves here.

Footnote: Wonky photos, proper food, genuine adventures — The Flexible Chef.