The primary raw materials for bread are:-
- flour;
- yeast;
- salt;
- water.
So without these materials no bread can be made.
Secondary raw materials are materials which improve the dough or final product in one way or another.
In general the quality improvements are:
- a better taste;
- an increased softness;
- a bigger volume;
- a better internal structure;
The secondary raw materials for bread are:
- fats, improvers including emulsifiers;
- sugars;
- milk products;
- malt products.
But you have to realise that if you are preparing a raisin loave, raisins are also a primary raw material. And if you are preparing a milk loave, milk powder is also a primary raw material.