If thou tastest a crust of bread, thou tastest all the stars and all the heavens.
- Robert Browning
We were discussing bread recipes the other day. One of the things we noticed was that some recipes (especially for whole wheat bread) called for two types of flour. It got me thinking about the different bread ingredients. What are they? And what purpose do they serve?
Here is what I found…
These are probably the most important bread ingredients. Most breads need to rise. This is the purpose of the leavening agent. Basically, bread can be leavened in two ways:
- Baking powder and/or baking soda
I talked about yeast in a previous post. Yeast is the essential ingredient that makes bread rise. It also adds to the flavour of the bread.
Baking powder and baking soda are chemicals. A chemical reaction between alkaline and acidic compounds produces the carbon dioxide that causes the bread to rise. Baking soda is pure sodium bicarbonate. It is an alkaline, and when mixed with an acid such as yogurt, buttermilk, vinegar, or lemon juice, carbon dioxide is produced. The reaction starts as soon as the ingredients are mixed. This means that you need to bake these recipes immediately or they will fall flat. Baking powder actually contains baking soda, but it also contains cream of tartar or monocalcium phosphate (acidic compounds), and usually a drying agent such as corn starch. There are single-acting and double-acting baking powders. Most baking powders are double-acting meaning they react once when they come in contact with moisture, and again when heated in the oven. With single acting baking powders, the chemical reaction is triggered by moisture, which again means you need to bake as soon as the ingredients are mixed.
Breads can be made with a lot of different types of flour, but the most common is wheat flour. Wheat flour contains two proteins, glutenin and gliadin. When these two proteins are combined with water, they form gluten. As the bread dough is kneaded, the gluten becomes stretchy and gum-like. The gluten gives the bread its structure by trapping the carbon dioxide released by the yeast.
Sometimes, the flour (whole wheat or rye for example) used does not contain enough proteins to produce gluten. In these cases, the recipe might call for a small amount of gluten flour to be added. Gluten flour is flour that has been treated to remove most of its starch and so it has proportionately more proteins.
In Canada, all purpose flour has a fairly high protein content (at around 13%)
Liquids (water, buttermilk, cream, juice, etc…):
Liquids dissolve and activate the yeast or react with chemical leavens (baking powder or baking soda). They also blend with the flour to create gluten.
Liquids other than water are used to enhance texture and/or flavour of the bread.
Sweetener (sugar, honey, molasses, jams, fruit, etc…):
Sweeteners add flavour to the bread. They also help to develop a brown crust.
Besides adding flavour, salt slows the rising time, allowing the bread dough more time to develop its flavour. Salt also helps to strengthen the gluten.
Eggs add nutrition, colour and flavour to bread. Eggs make the bread crumbs finer and they make the crust tender. An egg wash might be used to add colour to the bread crust.
Fat (butter, margarine, shortening, oil, etc…):
When fats are added, they make bread tender and moist. Fat slows moisture loss, helping bread to stay fresh longer.