In a glass measuring cup, whisk together water, milk, brown sugar and fresh yeast; let stand for about 10 minutes.TipAll ingredients should be at room temperature.
In the bowl of a stand mixer fitted with a dough hook combine all-purpose flour and salt. While kneading on low speed, gradually add eggs and knead to until the dough becomes soft, for about 5 minutes. If necessary, add more water, a tablespoon at a time. If you are kneading by hand, knead for about 10 minutes.
Add butter and knead well, until thoroughly incorporated, about 5 minutes. Transfer to a clean bowl. Cover with plastic wrap or with a kitchen towel, and let rise in a warm place until doubled in bulk, about 1 hour.TipIf you are using a kitchen towel, it's better if it's a bit moist - that will prevent a skin from forming on a dough.
Gently punch down the dough and remove from bowl and fold it into thirds like a business letter four times. Cover with plastic wrap or with a kitchen towel, and let rise in a warm place until doubled in bulk, about 1 hour.
Transfer the dough to a clean work surface. Divide it into 18 equal pieces (optional: Use a scale to be precise - every piece should weight around 90g / 3.2 oz). Using your hands, shape each piece into a round ball and let rest for about 5 minutes, for easier shaping.
Shaping and Proofing #3
Using your hands, roll dough into a 35 cm / 14 inch rope. Tie rope into a simple knot in the middle, leaving a bit of length at each end. Pull one end up and over and tuck it into the center. Pull the remaining end down and under, pushing it through the bottom of the knot and up into the center. Place on a baking sheet lined with baking paper, leaving some space between each roll (they will rise). Repeat process with remaining dough. Cover with plastic wrap or with a kitchen towel, and let rise in a warm place until doubled in bulk, about 1 hour.
Preheat your oven to 230 °C / 450 °F. If you want a shiny crust, lightly brush tops of the Kaiser rolls with egg wash or sprinkle with water (we prefer the latter). Lower the oven temperature to 210 °C / 410 °F and bake for about 20 - 25 minute, until golden brown. After about 8 - 10 minutes, switch to a convection oven setting.TipOptionally you can sprinkle the Kaiser rolls before baking with different toppings like poppy seeds, sesame, fried onions...
Transfer to a wire rack and let cool completely, then serve.
Store baked Kaiser rolls in a bread bag at room temperature or freeze baked Kaiser rolls for up to a month. When serving, leave them for 1 hour at room temperature, then serve.