The flavor and texture of kimchi changes dramatically as it ferments, making it more or less appropriate for different applications. The following are commonly recognized (but not industry-regulated) stages of fermentation; telling them apart is a matter of smelling or tasting them.
Flavor and Texture: crunchy, sweet, salad-like
Traditional uses: with rice, kalguksu (knife-cut noodle soup), juk (porridge), bossam (boiled pork belly), Korean barbecue, raw oysters
Other suggested uses: with rich meats or seafood, cold noodles, or grain bowls
Flavor and Texture: tangy, crisp-tender
Traditional uses: banchan (small side dishes essential to every Korean meal); with rice
Other suggested uses: condiment for tacos, hot dogs, burgers, or sandwiches; blended into creamy dips
Flavor and Texture: sour, tender
Traditional uses: kimchi jjigae (kimchi stew), kimchi bokkeumbap (kimchi fried rice), kimchi jeon (kimchi pancakes)
Other suggested uses: braised and stir-fried dishes, tacos, burger topping
Flavor and Texture: extremely tender, sour, deeply complex
Traditional uses: kimchi jjigae, kimchi bokkeumbap, kimchi jeon, kimchi jjim (braised kimchi and pork)
Other suggested uses: braises, stews, stir-fries