Step 1

Place cauliflower florets into a large canning jar. Add garlic, crushed red pepper flakes, mustard seeds, and peppercorns.

Step 2

Bring vinegar, water, sea salt, and sugar to a boil in a small saucepan over medium-high heat. Reduce heat and simmer until salt and sugar have dissolved, about 5 minutes.

Step 3

Pour mixture over the cauliflower mixture, seal, and let cool for 1 hour.

Step 4

Place jar in the refrigerator for 24 hours, shaking every 8 hours.