Preheat oven to 450℉
Line a pan with parchment and set aside. Grab your perforated pan if you have one and lightly spray with oil. If you do not have one, just place bread loaves on a sheet pan.
Heat water in a glass Pyrex mixing cup until it reaches approximately 108-110℉. Water that is too cool or too hot will not activate the yeast, so try to be as accurate as possible.
In bowl of a stand mixer, combine instant yeast, sugar, and salt, and pour in warm water. Stir with spoon and set aside for a few minutes to see if yeast activates (gets foamy.)
Add sourdough discard, 1 cup (120 grams) of flour, and butter. Mix with spoon again until well combined.
Add 2 more cups of flour (240g) to the mixture and attach to mixer. Using the dough hook, knead for 5-7 minutes, adding about 1-2 tablespoons of flour at a time if it seems too sticky/not holding up well. The dough will come together nicely into a smooth ball, but will still be tacky (this is normal for most bread dough.) If it is too sticky, continue adding flour until it no longer clings to your fingers.
Remove to a scale and weigh the dough. Divide weight in half to get the size of 2 equal dough balls. You can also eyeball it and cut in half. Just remember, the bake time will be different if you have majorly different sized loaves.
Right away, get to shaping the dough. For each dough: Roll into a large rectangle, mentally divide into thirds, and fold the far right 1/3 over the center 1/3. Lastly, fold the left hand 1/3 section onto the 2/3 section, so it becomes another long skinny rectangle. Fold in half from top to bottom, so both open ends are stacked on top of each other. Then roll out again, shaping another long rectangle, but skinnier. This time take into account the size of your pan with regards to the length of the dough. It should be just a bit shorter than the length of your pan. From the length of the dough, tightly roll like you would a cinnamon roll. Pinch seam and fold ends under. See video for visual instructions.
Place dough rolls in pan.
Using a sharp knife make dashes (—/—/—) into the top of the dough.
Cover with a kitchen towel, and allow to rise for about 40 minutes. I usually leave it on top of my stove as the oven preheats since it is nice and warm.
Once doubled in size, splash some water on the top by using your finger tips flicking the water at it. Next, grab a few ice cubes and as you open the oven, toss the ice into the bottom of the oven. Also put your bread in at this point. Lower the oven temperature to 425 and bake for 16-20 minutes, until dark golden brown and internal temperature is about 190-200F. Check bottoms to see if they look cooked enough too.
Place baked bread on to a wire rack to cool. Leaving bread on a hot pan will create steam between the bottom of the bread and the pan, thus making it soggy. Do not do that.
Allow to cool down before cutting into fresh bread. Enjoy!
