This might be the earliest depiction of a pretzel. Hortus deliciarum from Alsace, 12th century.
My approaching holiday in Germany made me crave these pretzel rolls. I'm sure you'll know what pretzels taste like, but have you ever eaten a fresh roll with the same flavour? I must say that these are one of my favourite rolls and are such a tasty breakfast filled with just cheese or tomato, mozzarella and basil.
Normally lye is needed in order to accomplish the distinct pretzel taste, but instead of using lye I practiced some science and created sodium carbonate out of sodium hydrogen carbonate (bicarbonate of soda). Sodium carbonate is better to work with than lye and the end result is better than with sodium hydrogen carbonate. And please do not be afraid of what I'm about to describe. I'm the least scientific person ever when it comes to chemistry but I easily managed to do this. I just like the look of the formulas and my scientist friend checked their correctness.
25g dry yeast
3tbsp sodium carbonate (to be made from sodium hydrogen carbonate, see below)
Sea salt flakes for sprinkling on the top
Mix the flour, salt and dry yeast with lukewarm water. Add the water slowly as you might not need to whole 400ml. Knead to an even bread dough and let rest in a bowl covered with a tea towel for one hour. While the dough is rising there's time to prepare the sodium carbonate.
The formula of sodium hydrogen carbonate:
The formula of sodium carbonate:
The thermal decomposition of sodium hydrogen carbonate:
2NaHCO3 → Na2CO3 + H2O + CO2
Place about 6 tablespoons of sodium hydrogen carbonate in an oven dish and heat at 150-180C for about 30-40 minutes. Mix it occasionally. This gives off a little water vapour and carbon dioxide as the sodium carbonate that we want is being made. Once it comes out of the oven dissolve three tablespoons of sodium carbonate into one liter of hot water.
Shape rolls of the dough and roll them in the sodium carbonate water, about one minute each. Make an x-cut across the rolls with a knife and sprinkle some sea salt flakes on the top. Place the rolls on a baking tray and bake at 220C for about 20-25 minutes.
Enjoy the baking and science!