Cut the 1 结球白菜 大头，约5–6磅，纵向四等分后切成2英寸大小 into quarters lengthwise, then chop crosswise into roughly 2-inch pieces. Place in a very large mixing bowl or clean pot.

Sprinkle the ½ 杯 粗盐 非碘盐；用于腌制白菜 over the 1 结球白菜 大头，约5–6磅，纵向四等分后切成2英寸大小 in layers, tossing to distribute evenly. Using your hands, massage the ½ 杯 粗盐 非碘盐；用于腌制白菜 into the 1 结球白菜 大头，约5–6磅，纵向四等分后切成2英寸大小 for 2–3 minutes until it begins to soften slightly. Let it sit for at least 1–2 hours (or up to overnight), tossing every 30 minutes. The 1 结球白菜 大头，约5–6磅，纵向四等分后切成2英寸大小 will release a significant amount of liquid and wilt considerably.

Rinse the salted 1 结球白菜 大头，约5–6磅，纵向四等分后切成2英寸大小 thoroughly under cold running water 2–3 times to remove excess ½ 杯 粗盐 非碘盐；用于腌制白菜. Taste a piece — it should be pleasantly salty but not overpowering. Transfer the rinsed 1 结球白菜 大头，约5–6磅，纵向四等分后切成2英寸大小 to a colander and let it drain for at least 15–20 minutes. Gently squeeze out any remaining excess water with your hands.

In a small saucepan, whisk together the sweet rice flour and ½ 杯 水 用于制作糯米粉粥 until smooth. Heat over medium, stirring constantly, until the mixture thickens into a translucent, pudding-like porridge, about 3–5 minutes. Remove from heat and let cool completely to room temperature.

In a large mixing bowl, combine the cooled rice flour porridge, gochugaru, minced 瓣 大蒜 切碎或压碎, grated 汤匙 新鲜生姜 去皮并细磨, fish sauce, salted shrimp (if using), and 1 茶匙 砂糖 有助于启动发酵. Stir everything together until a thick, uniform paste forms. Taste and adjust — add more gochugaru for heat, fish sauce for saltiness, or 1 茶匙 砂糖 有助于启动发酵 for balance.

Add the drained 结球白菜 大头，约5–6磅，纵向四等分后切成2英寸大小, julienned 1 个中等 白萝卜 去皮并切成火柴棍状, and 6 根 青葱 切成1英寸大小 pieces to the mixing bowl with the kimchi paste. Using clean hands (wear gloves — gochugaru stains!), toss and massage everything together until every piece of 结球白菜 大头，约5–6磅，纵向四等分后切成2英寸大小 is thoroughly coated with the red paste. Work the paste into the vegetables evenly for 3–5 minutes.

Pack the kimchi tightly into clean glass quart jars (two 1 quart jars or one half-gallon jar), pressing down firmly after each handful to eliminate air pockets. The liquid released by the vegetables should rise to cover the kimchi. Leave at least 1–2 inches of headspace at the top of each jar — the kimchi will expand as it ferments.

Seal the jars and leave them at room temperature for 1–2 days to begin fermentation. Once or twice a day, open each jar and press the kimchi down firmly with a wooden spoon or your fingers (called 'burping') to release trapped gases and keep the vegetables submerged under the brine. You'll notice bubbles forming — that's good! Taste daily.

Once the kimchi reaches your preferred level of tanginess (usually after 1–2 days at room temperature in warm weather, or 2–3 days in cooler weather), transfer the jars to the refrigerator. Cold temperatures slow fermentation dramatically. The kimchi is delicious eaten fresh (geotjeori style), but deepens in flavor over 1–4 weeks in the refrigerator. It keeps well refrigerated for up to 3 months.