Faults caused by recipe balance and not caused by baking and mixing methods are described.
There are specific cake faults caused by imbalance of aerating agents, liquids, eggs and fats (opening and closing ingredients). Two faults are designated ‘M’ and ‘X’ faults which relate to the shape produced when the cake is cut.
THE ‘M’ FAULT
If too much baking powder is used the cake will sink in the centre. This fault occurs when any aerating or ‘opening’ ingredient is used in excess causing the cake to rise more than the structure can support. The cell structure then breaks, releasing gas and the centre collapses. The opening and closing agents act as opposites. For example the ‘M’ fault can also be caused by using insufficient liquid. The same fault can be caused by using too much sugar. Excess sugar in a recipe produces a cake with a crisp top crust and a tendency to be dry.
An ‘M’ fault may be corrected by using less sugar, less baking powder or more liquid to balance the recipe.
THE ‘X’ FAULT
If too much of a closing agent, e.g. liquid, is used, the cake produced has a ‘close’ texture. That is, it is dense, tough and rubbery. After baking, the sides tend to collapse inwards forming a sort of ‘X’ shape called an ‘X’ fault. There is often a region of very dense crumb texture or ‘bone’ near the bottom of the cake.
Cakes demonstrating an ‘X’ fault usually have too much liquid in the batter. As the extra water turns to steam it aerates the structure. While in the oven the cake volume is good, but as the cake cools after baking the steam condenses and stops supporting the crumb structure. The cake then begins to shrink and collapse, especially at the sides. As there is more liquid at present the starch gelatinises quickly and fully giving a rubbery crumb texture. A cake with an ‘X’ fault can be improved by reducing the liquid or increasing the sugar or baking powder.
The role of egg in cake recipe balance is more complex because it acts as both an aerating ingredient and a liquid. Although more air may be beaten into the batter, it will not be held there. Instead, the batter will usually curdle because of the extra liquid. The cake produced will be heavier with a coarse crumb texture. The yolks give it a more pronounced yellow colour.
The effect of fat in cake recipe balance should also be considered separately. Too much fat gives a batter that tends to flow or collapse, producing a cake that is small with a flat top. The texture is very soft and may be greasy. The crust will be soft and moist. There may be a ‘bone’ near the bottom of the cake where the crumb tends to collapse.
If too little fat is added to the cake, less aeration occurs during mixing. The proteins are not shortened by the fat so the batter does not flow sufficiently and the cake has a characteristic point, a raised peak and is small. The texture is noticeably dry and tough for the same reasons.
METHODS OF CORRECTING FAULTS
Apart from guidelines already discussed for correcting the ‘M’ and ‘X’ faults, examination of the balance of a formula enables recognition of limits for each ingredient. To study this, convert the quantity of each ingredient to a percentage of the flour of any formula. In a good normal cake, the following recipe is used:
60% – Sugar
85% – Total liquid (eggs, milk, water)
60% – Fat
1 – 3.5% – Baking Powder
If the sugar content of a recipe is higher than 60% of flour weight, the total liquid must be increased to above 85% and/or the baking powder lowered. On the other hand, if the liquid content is above 85% then the sugar content will need to be above 60% to produce a good cake. The same result would be attained by increasing the baking powder. Thus, diagnosis of cake faults need not be a haphazard process, but can be carried out in a logical and scientific manner.