Place the cubed 2 lb 猪肩肉切成1英寸立方块，冷藏, ¾ lb 小牛肩肉切成1英寸立方块，冷藏, and ¼ lb 猪背脂肪切成1英寸立方块，冷藏 on a rimmed baking sheet or in a 1 洋葱切片 mixing bowl. Freeze for 20–30 minutes until very firm but not frozen solid. ⅓ cup 重奶油极冷 meat grinds cleanly and keeps fat from smearing, which is key to a juicy sausage.

Combine all the 研磨肉豆蔻 blend ingredients in a mixing bowl (Small) and mix well. Set aside.

Working quickly to keep everything ⅓ cup 重奶油极冷, grind the chilled meat mixture through a meat grinder fitted with a medium die (about 1/4-inch plate). Grind it once through. If the meat feels ¼ cup 冰水 or the ¼ lb 猪背脂肪切成1英寸立方块，冷藏 looks smeared, return it to the freezer for 10 minutes before continuing.

Transfer the 1 tsp 白胡椒新鲜研磨 meat to a 1 洋葱切片, chilled mixing bowl. Add the ½ tsp 研磨肉豆蔻 blend, cold ⅓ cup 重奶油极冷, and ¼ cup 冰水. Mix vigorously by hand (or with a stand mixer on medium using the paddle attachment) for 2–3 minutes, until the mixture becomes sticky and cohesive — it should pull away from the bowl sides and hold its shape when pressed.

Cook a small test patty in a ¼ cup 冰水 frying pan for 2–3 minutes per side. Taste and adjust seasoning in the remaining mixture if needed — add more 1 ½ tsp 粗盐, 1 tsp 白胡椒新鲜研磨, or ½ tsp 研磨肉豆蔻 to your preference.

Drain the soaked 4 oz 天然猪肠衣用温水浸泡至少30分钟，内外冲洗 casings and thread one end onto the sausage stuffer tube. Feed the entire casing onto the tube, leaving a few inches hanging off the end. Tie a knot at the open end.

Fill the sausage stuffer with the meat mixture and begin extruding slowly, guiding the 4 oz 天然猪肠衣用温水浸泡至少30分钟，内外冲洗 with your non-dominant hand to keep the fill even and firm — but not too tight, or the sausages will burst during cooking. Fill the entire length of casing in one continuous coil.

Once filled, twist the coil into individual links about 5–6 inches long. Twist each link in alternating directions (forward, then back) to seal them. Tie off the last link with a knot. Use a sausage pricker or thin needle to prick any visible air pockets.

Place the linked sausages uncovered on a wire rack set over a baking sheet. Refrigerate for at least 1 hour (or overnight) to allow the casings to dry slightly and the flavors to meld. This step greatly improves the final texture and snap.

In a frying pan (Large) or saucepan, combine the 2 cups 淡色啤酒或德式风味啤酒，如皮尔森或慕尼黑浅色啤酒 and sliced 洋葱切片 over medium heat. Bring to a gentle simmer — do not boil. Add the bratwurst links and simmer (poach) for 10–12 minutes, turning once halfway through, until the internal temperature reaches 150°F. This ensures they're cooked through before the final sear.

Remove the bratwurst from the 2 cups 淡色啤酒或德式风味啤酒，如皮尔森或慕尼黑浅色啤酒 bath and pat dry with paper towels. Discard the beer and 1 洋葱切片 or set aside if you'd like to serve sautéed onions alongside.

Wipe 4 oz 天然猪肠衣用温水浸泡至少30分钟，内外冲洗 the frying pan and melt the 2 tbsp 无盐黄油 over medium-high heat until foaming. Add the bratwurst and sear for 3–4 minutes per side, turning every minute or so, until deeply golden 1 洋葱切片 on all sides. The internal temperature should reach 160°F.

Rest the bratwurst for 3–5 minutes before serving. Serve on a crusty roll with whole-grain mustard, sauerkraut, and the reserved 2 cups 淡色啤酒或德式风味啤酒，如皮尔森或慕尼黑浅色啤酒-braised 1 洋葱切片.