Start by warming the water and then pour it into the bowl of a stand up mixer equipped with a dough hook.
Add the brown sugar and the packet of yeast and mix on slow until the sugar is dissolved. Allow 5-6 minutes for the yeast to begin feeding on the sugar.
Meanwhile warm the beer in a small pan over medium heat.
Melt the stick of butter in the microwave for about 40 sec.
Add the melted butter, warmed up beer, salt and the two types of flour to the now activated yeast and begin mixing on low.
After about 3 minutes turn up the speed to medium. Once the dough pulls away from the mixing bowl stop the mixer, take it out an place it onto a lightly floured surface.
Using your hands form a ball and place it inside a well greased glass bowl. Grease the dough ball and cover the bowl well before you let it rest in a warm area of your kitchen.
Wait until the dough doubles in size. Depending on the altitude of your location the time will vary. If you live at high altitude the dough will double faster, in less than an hour.
While waiting, prepare a pot of water and the baking soda.
Once the dough has doubled, take it out and divide it in half, then each half in half and so on until you have 16 pieces.
Roll out each piece into a log and use scissors to snip the sides and create a pine tree like shape from each log.
Bring the pot of water to a boil and turn on your oven to 400° F.
Make an egg wash by beating the egg well.
Once the water is boiling slowly add the baking soda. Immerse each pretzel tree for about 45 sec making sure it gets coated with boiling water all over. Take out with a slated spoon, carefully pat dry with a paper towel before setting down onto a parchment paper lined sheet pan. (This step will cause the crust of the pretzels to brown. It will also impart the familiar pretzel crust flavor. If you want darker pretzels, add more baking soda. If you don't want your pretzels to brown too much add less).
Once you have all the pretzels ready, brush them with the egg wash and season them with kosher salt.
Place them in the oven and bake until they begin to turn brown, approximately 20 min.