Pack the Jar
Tightly pack the kimchi mixture into a clean 2-quart (half-gallon) glass jar. Press down firmly on the kimchi with your fist or a spoon as you go. This helps remove air pockets and encourages the brine to rise.
Leave at least 1-2 inches of headspace at the top of the jar. The kimchi will expand and produce more brine as it ferments, so this space is essential to prevent overflow.
Wipe the inside rim of the jar clean. Loosely cover the jar with its lid. You don’t want to seal it airtight, as fermentation creates gases that need to escape.
Ferment at Room Temperature
Place the jar on a plate or in a shallow bowl to catch any brine that might bubble over.
Let the jar sit at a cool, dark room temperature (around 65-70°F or 18-21°C) for 1 to 5 days. Keep it out of direct sunlight.
Check it daily! At least once a day, open the lid to “burp” the jar and release the built-up gases. Use a clean spoon to press the kimchi down, ensuring it stays submerged under the brine. You should start to see bubbles and notice a tangy, sour smell developing—these are great signs!
Start tasting it after day 2. When it has reached a level of sourness and tang that you enjoy, it’s ready.
Notes
Refrigerate and Enjoy
Cold temperatures will dramatically slow down the fermentation process. Your kimchi is ready to eat right away, but the flavor will continue to develop and deepen over the next week or two.
Once your kimchi is fermented to your liking, tighten the lid and move the jar to the refrigerator.