Discussing the formulation of a cake is quite challenging because there are numerous recipes that depend on the type of cake one aims to achieve. However, it’s possible to provide some general recommendations, although it’s always essential to consider that the method of mixing and the desired final characteristics of the cake may necessitate some variation.

On the web, we can find many formulations based on units such as cups, tablespoons, or teaspoons. These formulas are straightforward and easy to prepare for an individual at home. However, caution must be exercised as the amount of sugar that fits in a cup is not the same as that of flour or oil. One recipe that has become very famous in Spain is the “3, 2, 1” cake. It starts with a yogurt (let’s say 125g). Once the yogurt is incorporated, we use that container to include one unit of oil (90g), two units of sugar (320g), and three units of flour (150g), plus 3 eggs (141g), and a packet of baking powder (16g). It’s a very simple formula at a domestic level and seems not too heavily laden with sugar, but if we look at the weight, it contains more than double the amount of sugar compared to flour.

Another well-known formula, due to its simplicity, in the Anglo-Saxon world is the Pound cake. It’s based on the idea that the quantity of the main ingredients (flour, sugar, and fat) is the same (one pound, which is nearly half a kilo). This is supplemented with eggs (about 300g), some milk, leavening agent, and flavouring substances. If we compare it with the previous 3, 2, 1 cake, we see that the percentage of sugar is lower, but the fat content is higher, and this fat is usually butter, which has a higher percentage of saturated fats than the oil in the first recipe.

Below are some recipes.

	Yellow layer cake	White layer cake1	Angel food cake1	Chiffon cake2
Flour	29.8	25.8	15	14
Sugar	25.5	25.8	41.5	32
Fat	13.4	13		10.75
Egg	14.8	17.8	41.5	42.75
Milk	14.8	15.4
Baking powder	0.7	0.9	0.6	0.12
Salt	0.6	0.5	0.6	0.38
Flavours	0.4	0.5	0.8

¹In these preparations, only egg whites are used, not whole eggs.

²In this cake, oil is used instead of fat, half of the sugar is powdered, and the egg is separated into 32 parts of whites and 10.75 parts of yolks.

As you can see, there are very different formulas, which can vary depending on the types of ingredients used (type of egg, fat or oil, sugar particle size, etc.). Let’s start with three basic and classical rules:

• The amount of sugar should be similar to that of flour.

• The amount of eggs should be similar to that of fat.

• The amount of liquid ingredients should be similar in weight to that of flour or sugar.

Within liquid ingredients, whole milk, fresh eggs, and water, if added, are included. The improvements in the quality of raw materials that occurred in the first half of the 20th century, as a result of various research studies, have allowed for modifications to these rules. These improvements have involved better adaptation of flours and fats. In the case of flours, low ash contents (0.3-0.4%) and protein contents (7-9%) are recommended. In some countries, it’s common to bleach flours and treat them with chlorine, resulting in higher-quality cakes. However, this technique is prohibited in other countries. It’s also demonstrated that finer and more uniform flours (micronization) yield cakes with higher volume and finer texture due to easier flour dispersion in the batter. In the case of micronization followed by flour classification using air cyclones, the finest fraction should be discarded as it contains higher protein levels. The most significant advancement in fats was the introduction of emulsified fats, allowing for increased liquid addition, more stable batters, and obtaining tenderer cakes with longer shelf life. After these improvements, the three general rules have been modified as follows:

• The amount of sugar should be slightly greater than that of flour.

• The amount of egg should be slightly greater than that of fat.

• The amount of liquids should slightly exceed that of sugar.

Based on these rules, it should be noted that the amount of sucrose usually does not exceed 140% based on flour, although it’s more common to use levels around 125%. The amount of liquids should be sufficient to dissolve the sugar and gelatinize the starch, so the amount of sugar should not exceed 90-95% of the liquids. An excessive addition of sugar produces cakes with thicker and irregular crumb, greater volume, and less firm texture. Conversely, a reduction in sugar content results in cakes with lower volume, finer and more regular crumb, and less tender texture. Excess oil results in cakes with lower volume and a greasy mouthfeel, while a reduction produces a coarser crumb, greater volume, and tougher and drier texture. As for the level of liquids, an increase yields cakes with finer crumb, tender texture, and greater volume, while a reduction has the opposite effect. However, an excessive amount of liquids can also cause the cake to collapse after baking. As can be seen, these rules are very general and do not take into account the possible substitution of sucrose with glucose or fructose syrup, or the use of different amounts of egg white and yolk, which should be considered separately.

The substitution of sucrose with high-fructose syrups (42%) produces cakes that are darker, slightly lower in volume, have a greater tendency to harden, a more open crumb, and a thicker crust. However, they are sweeter, as fructose has a higher sweetening power. Nevertheless, by slightly adjusting the formula, cakes similar to the originals can be achieved. For this purpose, it’s necessary to reduce the fat content by 10%, replace vegetable fats with plastic fats, and add 7-8% emulsifier. It’s also advisable to use a slower-acting leavening agent. This example demonstrates that whenever there is a variation in the components used, reformulating the product is necessary.

Egg proteins have a structural effect counteracted by the tenderizing effect of fats. If unemulsified plastic fats are used, the same amount of egg and fat is usually used. However, emulsified fats have a greater tenderizing effect, and their content can be reduced by 15-20%. This applies to whole eggs, but the use of varying amounts of yolk or white should prompt reconsideration of the formula. Whites have 15% higher moisture content than whole eggs and 1.7% lower protein level. Therefore, if egg is replaced with whites, the level of whites should be increased, or the fat level should be reduced. This is only valid when using fresh whites, as powdered whites have much higher protein content, and the changes should be different. Yolks, on the other hand, contain 20% more lipids and 24% less moisture than whole eggs, which should also be taken into account when reformulating the recipe.

Replacing plastic fats with vegetable oils will result in cakes that are excessively moist, which may not be preferred by consumers in certain countries, although it is favoured in other countries, where these preparations are more common. This effect can be minimized by reducing the oil content by 5% and the leavening agent by 20%, while increasing the water content by 6% to compensate for the effect on the batter rheology. A similar effect can be achieved by increasing the level of eggs.

So far, we have discussed the formulation of cakes whose structure is based on obtaining a stable emulsion of oil and liquids. However, there are special cases that need to be considered separately. Cakes that owe their structure to the ability to trap air from egg whites are based on different rules. Among these foam cakes, we can distinguish between those that only incorporate egg white in their formula and those that use whole egg. In the former case, the two basic rules are:

• The amount of sugar should be equal to that of egg white.

• The amount of flour should be one-third of that of sugar.

In the case of incorporating whole egg, the rules would be:

• The amount of sugar should be equal to or slightly greater than that of egg.

• The amount of liquids (eggs, milk, and/or water) should be slightly greater than that of sugar (1.25:1).

• The amount of egg should be greater than that of flour.

• The sum of the weight of eggs and flour should exceed that of sugar and the rest of the liquid components (milk and water).

Another special case is low-calorie cakes. The caloric content of cakes is fairly evenly distributed among sugar, fat, and flour. Sucrose can be replaced with fructose. Since fructose has a higher sweetening power, its weight can be reduced by almost half without loss of sweetness. However, this will affect the texture and crumb of the final cake, so small adjustments to the formula will be necessary. Another alternative is to replace sucrose with bulking agents, such as polyols, especially maltitol. This substitution will yield cakes with similar volume but with a lighter crust, as these bulking agents do not participate in Maillard reactions. It’s also necessary to consider the laxative effect of these bulking agents. However, by replacing sugar alone, it’s difficult to reduce the calorie content of the cake by more than 33%, and to do so, it will be necessary to reduce the amount of fat in the formulation. Fat can be replaced with a mixture of hydrocolloids or thickening agents and water. These products help retain water and improve the juiciness of the final cake, compensating for the reduction in fats. Products such as xanthan gum, psyllium, or pregelatinized flours can be used. However, fats also have a stabilizing function for foams, as they surround the air bubbles. This effect, which is not achieved with the addition of hydrocolloids, can be achieved with the addition of emulsifiers. Therefore, a combination of emulsifiers and hydrocolloids can be effective. However, I do not recommend complete substitution, as it reduces acceptability, but a substitution of 50 to 66% is advisable. In these cases, it’s also necessary to consider the higher moisture content of cakes, and therefore a greater risk of microbial growth. This can be addressed with the help of preservatives, such as sorbates. To further reduce the calorie content, we can rely on the substitution of part of the flour with a fibre such as cellulose. However, this substitution should not exceed 33%, and the chosen cellulose should have a reduced particle size.

We must also contemplate certain considerations when making gluten-free cakes. For these preparations, we can start with the same recipes we use with wheat flour. Wheat flour can be replaced with neutral gluten-free flour, such as rice flour. The problem with this flour is that it may have a larger particle size than wheat flour, and as we have discussed in the blog, the particle size of flours, especially in foam-type cakes, which are more aerated, is important. Therefore, we must find rice flours that are as fine as possible. These are more difficult to find, but they are already available. It’s also possible to use mixtures of rice flours and cornstarch, but an excess of cornstarch usually results in cakes that are excessively pasty, with an unpleasant texture. A second problem with these preparations is that the texture is excessively crumbly. This is because the proteins in wheat, when coagulating during baking, help to “stick” and generate more cohesive crumbs. Fortunately, we have another ingredient that can help us in this task, which is egg white. Therefore, in these types of preparations, the amount of egg or egg white is usually increased.

As you can see, any modification in the formulation is complex and involves several changes to compensate for certain effects. It should also be noted that the rules given are very general, and some preparations slightly deviate from them.