How to Make Kimchi at Home: The Edible Chemistry Method

Kimchi is one of the most rewarding fermented foods you can make at home. The process is hands-on, the science is fascinating, and the results — a jar of bright, spicy, alive fermented vegetables — are far better than anything you'll buy in a shop.

This is our method, the one we teach in our kimchi workshops in Lisbon. It's designed for complete beginners.

What Is Kimchi?

Kimchi is Korea's most iconic fermented food: salted and spiced vegetables (most often Napa cabbage) fermented by lactic acid bacteria. It's been made for thousands of years — originally as a preservation method, now celebrated worldwide for its complex flavour and probiotic benefits.

Good kimchi is simultaneously salty, sour, spicy, umami, and a little funky. The proportions shift as it ferments — fresh kimchi is bright and crunchy; aged kimchi is deeper, more sour, and extraordinary in cooking.

What You'll Need

Vegetables: 1 medium Napa cabbage (about 1 kg), 4-6 spring onions cut into 5cm pieces. Optional: daikon radish, carrots, cucumber.

Kimchi Paste: 2-3 tablespoons gochugaru (Korean red chilli flakes — not a substitute), 4 cloves garlic minced, 1 teaspoon fresh ginger grated, 1 tablespoon fish sauce (or soy sauce for vegan version), 1 teaspoon sugar or honey.

For Salting: 2-3 tablespoons non-iodised salt (sea salt or kosher salt).

Equipment: Large mixing bowl, clean glass jar (1 litre) with a lid, gloves (gochugaru stains everything).

Step 1: Salt the Cabbage

Cut the cabbage into quarters lengthways, then into bite-sized pieces (about 5cm). Place in a large bowl.

Sprinkle the salt over the cabbage and massage it in firmly for 2-3 minutes. The salt draws moisture out of the cabbage cells — this is the foundation of safe lacto-fermentation.

Leave to sit for 1-2 hours (or up to overnight). The cabbage will wilt significantly and release a pool of liquid. This is exactly what you want.

Rinse the cabbage 2-3 times with cold water to remove excess salt. Taste it — it should be pleasantly salty, not overwhelming. Squeeze out as much water as possible with your hands.

Step 2: Make the Kimchi Paste

Combine gochugaru, garlic, ginger, fish sauce (or soy sauce), and sugar in a small bowl. Mix until a rough paste forms.

Taste it. It should be intensely flavoured — salty, spicy, garlicky. This is your seasoning base and it needs to be bold, because it will spread across a large quantity of vegetable.

Step 3: Mix Everything Together

In a large bowl, combine the drained cabbage, spring onions, and any other vegetables you're using.

Put on your gloves. Add the kimchi paste and mix everything thoroughly with your hands, massaging the paste into every piece of vegetable. Take your time — this is the most satisfying part of the process.

Taste as you go and adjust: more gochugaru for heat, more fish sauce for depth, more sugar for balance.

Step 4: Pack the Jar

Transfer the kimchi into your clean glass jar, pressing it down firmly as you go. The goal is to eliminate air pockets — you want the vegetables submerged in their own liquid.

Leave about 2-3cm of space at the top of the jar. As fermentation begins, gases will build up and the kimchi will expand slightly. Seal the jar.

Step 5: Ferment

Leave the jar at room temperature (18-22°C is ideal) for 1-5 days, depending on your preference.

Open the jar once a day to release gas and press the vegetables down if they've risen above the brine. Taste it daily — you'll taste it actively changing.

Day 1: Fresh, crunchy, intensely seasoned. Days 2-3: Slightly sour, more complex. Days 4-5: Noticeably tangy, funky, deeply savoury.

Once it reaches a flavour you enjoy, transfer to the fridge. Fermentation slows dramatically in the cold — your kimchi will continue to develop slowly for weeks to months.

Tips from Our Lisbon Kitchen

Use gochugaru, not another chilli. The flavour profile is unique and can't be replicated with cayenne or paprika.

Non-iodised salt only. Iodised salt contains additives that inhibit the bacteria you want to grow.

Room temperature matters. In Lisbon's warmer months, fermentation will be faster. In winter, slower. Taste daily and trust your senses.

Want to Learn In Person?

This recipe is a simplified version of what we teach in our kimchi workshops in Lisbon. In person, you'll learn the nuances that are hard to convey in text — the feel of properly salted cabbage, the smell of active fermentation, how to adjust the paste by taste.

Weekend sessions run throughout the year. Spaces are limited.

Book a Kimchi Workshop in Lisbon