In a small bowl set aside 4 tablespoon of the milk and heat it up to a lukewarm temperature. Add the sugar and stir. Now stir in the instant yeast, to activate it. Leave for 10 minutes and you should see a bubble forming on the top. If they do not form then the milk might have been too hot and you should start again.
In a large bowl mix the yeast-milk mixture, flour, melted butter, and salt. Using a stand or hand mixer with a dough hook attachment, need the dough for approximately 10 minutes to a smooth dough.
4 cups flour, ¼ cup butter, 1 teaspoon salt
Cover the dough with a tea towel and leave to rise at room temperature for approximately 45 minutes. The dough should double in size.
After the resting time, knead the dough again briefly to remove any excess air that might have built up.
Use a non-stick silicon baking mat or a lightly floured surface. Shape the dough into a long roll, and then divide off approximately 20 equal portions. You can weigh each piece of dough to be more precise. Mine were approximately 40 gr each. Roll each ball into an approximately 20 cm long "snake", which should be tapered at the ends.
To shape the Pretzel heart - take two "snakes" and wrap the end pieces around each other twice. Then you pull them apart outward and wrap the other two end pieces together to create the pointed bottom of the heart.
Leave the pretzels to rest for a further 20 minutes on a baking tray lined with parchment paper. Be careful, once you placed them on the parchment it is difficult to move them.
In the meantime, you can preheat your oven to 220°C/428°F top-to-bottom heat. In a large saucepan bring 1 liter of water with 1 teaspoon of salt to boil. Once the water is boiling, add the bicarbonate of soda to it. Be careful it bubbles when it is poured in. Remove the pot from the heat.
4 cups cups water, ½ cup bicarbonate soda, 1 teaspoon salt
Place a heart pretzel on a slotted spatula and carefully dunk it into the water bath. Make sure that the whole pretzel is submerged in the soda bat for 30 seconds. h Repeat the process with each heart.
Carefully place each heart, at a little distance from another, on the baking parchment. Be careful the dough may be very slippery. Sprinkle the pretzel hearts with pretzel salt.
Bake in the oven for 15-20 minutes until they achieved a deep golden brown color.