Traditionally this pastry consists of wheat flour, malt, salt, yeast and water.
Before putting it in the oven the Brezel is dipped for a few seconds in caustic soda (3 to max. 5 % in water). This provokes the typical brown color and special taste. Through the heat the caustic soda reacts with the surface of the pastry with carbon dioxide from the air and turns to sodium carbonate and water.
The formula for those interested in chemistry:
- Bakers use a special procedure for forming the loops.
- The dough string is rolled by both hands and extended for thinning it out at the ends. Then the string is kept by the hands on both hands and by a short, jerky motion the thicker middle part is given a 180 grade spin and at the same time put down on the work space. After that the two ends just have to be attached to the sides.
- This procedure takes about 1 second but it takes lots of time to practise. They say it takes year to be able to loop the perfect Brezel.
- Large bakeries have special machines for forming the Brezels.
Just found this post by a blogger written in catalan, have a look: