Breading and battering are two of the most commonly used techniques in cooking. These techniques are employed in both home and industrial kitchens. There are many types of breading and battering, and there are significant differences between homemade and industrial approaches. However, they often share a common ingredient: flour. In this series of entries, we will explore the types of breading and battering, the criteria for analysing their quality, and the influence of ingredients and processes in achieving a good breading or battering.

As you may know, these techniques involve giving a more or less complex coating to various foods. Commonly coated foods include meat products like chicken, fish such as hake, or vegetables like onions. However, most of the time, these are savoury products (with some exceptions). It is also possible to coat sweet products, but different techniques, such as coatings or glazes, are primarily used for that purpose.

Reasons for Breading and Battering

Before delving deeper, let’s understand the purpose of breading and battering. There are several reasons for using these techniques. Firstly, they allow you to achieve a crispy outer texture while maintaining the juiciness of the coated product on the inside. The coating dries out, creating the crispiness, while the moisture inside the products remains protected, preserving their juiciness. Here, we see two factors that determine the quality of breading or battering: the texture and crispness of the outer layer and the juiciness of the interior.

A second reason is the ability to introduce new flavours to certain products. While it can be challenging to add flavours to items like fish fillets or onions, breading or battering allows for the incorporation of a wide range of flavours aimed at improving or modifying the organoleptic quality of the final product. Through breading or battering, we can also diversify our range of products and culinary preparations.

One of the most significant reasons for the industrial use of breading and battering is cost savings. Typically, the cost of breading or battering is much lower than that of the products they are applied to. Therefore, the cost of the final product per unit of weight is reduced, even when considering processing costs. Often, production costs are reduced more than the selling price, leading to increased profits. When both costs are reduced equally, more cost-effective products are obtained, making them more competitive.

One of the reasons the breading industry has grown so much in the last 50 years is the ease of applying it on an industrial scale compared to the inconvenience of doing it at home. Although breading has been a common technique in many households, the need for preparation time, and extended frying, has led to fewer households and even restaurants opting to use it. Instead, they prefer to purchase pre-fried products that only require a quick and simple finish. However, the industry has identified the need for this final, albeit brief, frying as a potential limiting factor for the expansion of these products. This is due to the fact that many households are eliminating or minimizing their kitchen spaces, and frying is a technique that produces strong odours and mess. Therefore, it requires careful consideration in some aspects. For this reason, in recent years, many studies have focused on finding ways to finish these products through baking or microwaving, which can be quite complex.

Before moving on, let’s define what breading and battering are and discuss their different variations. In this entry, we will focus on homemade preparations and breading, leaving the topic of battering for the next entry.

Types of Batters

To classify these preparations, we can consider various aspects, but we will distinguish between homemade and industrial preparations.

Homemade Preparations

Flour Coating

Perhaps the simplest form of coating is flour coating. This technique involves coating the food item with plain wheat flour. The flour absorbs moisture from the item being coated, filling the gaps on the coated surface and making it more challenging for the juices to escape during cooking. This imparts a certain crispiness when it dries. Once the item is coated with flour, it can be either fried or sautéed in a pan with a small amount of oil. By reducing the exterior moisture of the product, the typical bubbling associated with frying is also minimized. This technique is particularly common in the southern region of Spain (Andalusia) and is often applied to various types of fish. In other parts of Spain, it is also used for meat products like blood sausage.

Batter

In general, the term “battered” refers to the process of coating a food item with a mixture of flour and egg. This preparation is also known in Spain as “a la romana,” especially in the case of hake or calamari. The function of the flour is similar to that in the previous technique, as it absorbs free water from the food item, dries the surface, and fills in the pores. This promotes better adhesion of the egg, which adheres more easily to a dry surface. During frying, the protein in the egg white coagulates, giving the final product a crispy texture. As we will see, this is the main difference between homemade batters, where egg plays a predominant role, and industrial batters, where egg usually plays a minor and complementary role.

Tempura

A third type of coating, more similar to industrial approaches, involves creating a batter in which the food item is dipped. Some food items, especially those with higher moisture content, may benefit from a preliminary dusting of flour to improve the adhesion of the batter. The viscosity of the batter is crucial in regulating the amount of batter that adheres to the final product, a term referred to as “pick up.” In these types of coatings, based on a mixture of flour and water, it is common to incorporate leavening agents (baking powder) to achieve a fluffier final product. For these coatings, and with a similar purpose to leavening agents, some authors recommend using carbonated water or beer instead of plain water. It is also possible to add flavouring substances in small proportions, such as salt, sugar, spices, etc.

In general, the term “tempura” is used when coating vegetables, although it can also be used for seafood and other products. “Gabardine” is a term primarily associated with coating shrimp. You can also find information about this technique by searching for the term “mass orly,” which is a type of batter used for this type of coating. However, while some authors distinguish these terms clearly, others use them interchangeably.

As mentioned, in these preparations, the viscosity of the batter is crucial, and therefore, the flour-to-water ratio plays a significant role. The thicker the batter (less water content), the more batter will adhere to the final product.

Breading

The definition of industrial breading and its various types will be discussed in more detail in the next entry. For now, let’s look at homemade breading. Breading involves applying a second layer (breadcrumbs) to the already battered product. First, a layer of beaten egg is applied to allow the breadcrumbs to adhere to the product. As mentioned earlier, it’s a good idea to apply a layer of flour first to improve the adhesion of the egg to the product. Therefore, the process typically involves flour coating, followed by a layer of beaten egg, and finally, the entire product is coated with breadcrumbs. Obviously, the weight of the coating is much heavier in this type of preparation. In some cases, a double battering occurs when a second layer of egg and breadcrumbs is applied, resulting in a much thicker coating that enhances crispiness.

Regarding breadcrumbs, there are various types with different particle sizes and shapes, including flavoured particles and even colouring substances. In a future entry, we will discuss the types of breadcrumbs in more detail. In these preparations, it is also possible to incorporate flavouring substances, such as salt or spices, into the beaten egg.

Industrial Approaches

In general, industrial batters can be divided into two types: those used as adhesives for subsequent breading and those with their unique characteristics. While both are applied in the form of a batter, the latter is slightly more complex. Unlike homemade batters, the use of egg is not as crucial in industrial applications.

Adhesive Batter or Interfacial Coating

This type of batter is applied solely to facilitate the adhesion of subsequent breading. It involves creating a paste with a high content of flour or starch. The viscosity of this paste significantly influences the amount of paste that adheres to the final product, and hence, the thickness of this layer. The flours or starches used can be native or modified, as we will discuss later. These batters do not contain leavening agents since their purpose is not to achieve a specific texture on their own. The final texture is more influenced by the subsequent breading. However, it is possible to incorporate additional ingredients into the mixture, such as gums, spices, aromatic substances, and protein products like some dairy or egg-based products.

Before applying this type of batter, it can be useful to perform a preliminary flour coating (often referred to as “predust”) to seal the pores, absorb moisture, and enhance the adhesion of this initial batter.

The required batter is usually prepared using conventional mixers, although there are advanced equipment options with better process control. These advanced devices analyse the batter’s viscosity, allowing for better adjustment, and control the temperature of the added water, which also affects viscosity. Excess batter is typically recirculated, so its viscosity should not be too high as it needs to be pumpable. However, it is important to note that the batter should be prepared just before use, as it can develop microbial issues if stored due to its high moisture content.

While water is the most common liquid used to dilute powdered products (flours and other ingredients), other liquids such as beer, carbonated water, milk, sauces, etc., can also be used. The aim is to modify the organoleptic characteristics, as is done in homemade battering.

Although it is not common, it is possible to apply this type of battering without subsequent breading.

Tempura

These industrial batters are very similar to homemade tempuras. As in other cases, a preliminary dusting of flour may be beneficial depending on the product being battered to improve adhesion. Similar to adhesive batters, they are based on creating a batter by mixing flours and/or starches with water, where the viscosity of this batter significantly determines the amount of batter that adheres to the product, which is known as “pick up.” The key difference with the previous type is that this batter gives the final product its unique characteristics, as it will not be covered with an additional layer. This is why these batters often incorporate leavening agents or leavening substances. This addition helps achieve a lighter and fluffier texture. It is also common for them to include ingredients for flavour, such as salt, sugar, spices, and colour, including natural substances with colouring potential. They can also incorporate certain gums that help regulate the viscosity of the batter, or protein products that contribute to colour development through Maillard reactions, such as dairy or egg-based products.

Unlike adhesive batters, these batters usually have higher viscosity (higher pick up) and are not pumpable. This is due to their increased viscosity and the risk of leavening agents starting to act as the temperature rises.

Factors Determining Batter Quality

The quality of a batter depends largely on its function—whether it will be the only coating given to the product or whether its primary function is to adhere the subsequent breading. It also depends on whether leavening agents or flavours are added. In these latter cases, formulation and the proper selection of leavening agents and flavourings are important. However, in these situations, viscosity is typically the most critical criterion for quality. To achieve the appropriate viscosity, a good selection of flour, the use of gums, and the proportion of water (how much water is incorporated per unit of flour) are essential. The possibilities are quite varied, and batters can have hydration levels ranging from 50% (50 parts of water per 100 parts of solids) to 300%. However, the typical range is between 100 and 200% hydration, with final solid levels ranging from 33 to 50%.

More viscous batters generally adhere better to both the product to be battered and the subsequent breading. Additionally, they maintain products that tend to stratify or settle better in suspension. To prevent settling, equipment that continuously mixes the batter is often used. However, excessively high viscosity makes these liquids non-pumpable and results in overly thick and irregular coatings. Excessive viscosity can also lead to the development of a gluten network if wheat flour is used, which affects the final texture. On the other hand, less viscous batters have difficulties when incorporating ingredients that tend to settle, adhere less effectively to the product, and complicate the adhesion of the subsequent breading. While they may be suitable for some applications, as they form a very thin film on the product, they are not the most common choice.

For this reason, viscosity control is typically a routine operation in the battering industry. Simple and fast equipment is preferred in the industry for this purpose. It is common to measure viscosity using instruments like Bostwick viscometers for thicker mixtures and cup viscometers for thinner ones. Rotational viscometers like Brookfield viscometers can also be used. Maintaining temperature control is crucial during these measurements because temperature affects the viscosity of the medium. Temperature control is equally important in the industrial process. While it is not common, excessive enzyme presence can also affect their activity based on temperature.

Apart from viscosity, adhesiveness is also an important factor. Certain ingredients, once hydrated, exhibit greater adhesiveness at the same hydration or viscosity level. Pre-gelatinized flours or starches, for instance, have greater adhesiveness compared to their non-pre-gelatinized counterparts. Additionally, flours with higher levels of damaged starch also have greater adhesiveness, albeit to a lesser degree than pre-gelatinized versions.