Air Fryer Magic: How Does It Make Things Crispy?

Air fryers have surged in popularity in recent years, with nearly 40% of U.S. homes owning one as of July 2020. They are a great way to get the crunch and flavour of deep-fried food with much less effort and oil. Air fryers work like small convection ovens, with a powerful fan that keeps hot air moving constantly above, below, and around food sitting on a grate or rack. This ensures even heating and helps evaporate water off the food's surface, which is critical for crispness. The chemical reaction that occurs is called the Maillard effect, where an amino acid and a reduction in sugars react to heat. While air fryers can make food crispy, they will not produce the same level of crispiness as deep-fat frying.

Air circulation and convection

Air fryers are essentially small, powerful convection ovens. They use a fan to circulate hot air around the food, cooking it more quickly and evenly than a conventional oven. This rapid circulation of hot air is what crisps up the food, similar to deep frying but without the need for oil.

The top section of an air fryer contains a heating mechanism and a fan. The food is placed in a fryer-style basket, and when the machine is turned on, hot air rushes down and around the food. This rapid circulation of hot air is what makes the food crisp.

The key to achieving crispy results in an air fryer is to ensure proper air circulation. Air fryers work best when there is plenty of room between individual items for the air to circulate. If the basket is overcrowded, the air cannot circulate properly, and the food will not cook evenly. It is recommended to cook in batches to avoid overcrowding the basket.

Another important factor is the amount of oil used. While air fryers require significantly less oil than traditional frying methods, a small amount of oil can help to improve browning and roasting. A drizzle or a quick spritz of oil is usually sufficient to achieve crispy results.

By combining rapid air circulation with a small amount of oil, air fryers can produce crispy and evenly cooked food without the mess and negative health impacts of deep frying.

Maillard effect

The Maillard effect (or Maillard reaction) is a chemical reaction that occurs when an amino acid and a reducing sugar react in the presence of heat. This reaction is responsible for the browning and crisping of food cooked in an air fryer.

The Maillard effect is named after French chemist Louis-Camille Maillard, who first described the reaction in 1912. It is a fundamental concept in understanding the chemistry of food and plays a crucial role in determining the colour, flavour, and texture of cooked foods.

In the context of air frying, the Maillard effect is the result of the hot air circulated at high speed by the air fryer coming into contact with the surface of the food being cooked. This process creates a chemical reaction that causes the food to brown and become crispy, similar to traditional frying methods.

The Maillard effect is particularly noticeable in dry" foods such as French fries, meats, vegetables, breaded items, and frozen foods, which tend to yield better results in an air fryer than "wet" foods. The high speed of air circulation and the even distribution of heat in an air fryer create optimal conditions for the Maillard effect to occur, resulting in the desired crispy texture and golden brown colour associated with fried foods.

It is important to note that the Maillard effect is different from burning or charring, as it occurs at lower temperatures and involves a specific chemical reaction between amino acids and reducing sugars. This reaction is responsible for the distinct flavour and aroma of many cooked foods, including those prepared in an air fryer.

Oil usage

Air fryers require significantly less oil than standard frying methods, but a small amount of oil is still recommended for the best results. Oil transfers heat more efficiently than air, and a thin layer of oil on food ensures good browning and even roasting. A drizzle or a quick spritz of oil is all you need to achieve a crispy texture and golden colour. Avocado oil is a good choice due to its high burn temperature. You can also use a non-stick cooking spray made with a healthier oil such as avocado oil.

When using oil in an air fryer, it is important to ensure that the oil is evenly distributed over the food. A simple kitchen spray bottle can help you achieve this. Additionally, overcrowding the air fryer basket should be avoided as it restricts airflow and can lead to uneven cooking. It is recommended to divide your food into several small batches to ensure proper airflow and even crispiness.

Some foods, such as mozzarella sticks, may benefit from the use of parchment paper to prevent the loss of cheese. However, parchment paper can prevent airflow and direct contact with the metal, resulting in less crispy food. If using parchment paper, ensure that it is specifically designed for air fryers and has holes in the bottom to allow for proper airflow.

While air fryers can be used without oil, the taste and texture will be different, and the food may not be as crispy. For the best results and to achieve the desired crispiness, a small amount of oil is recommended.

Basket overcrowding

Overcrowding the air fryer basket is a common mistake that can lead to disappointing results. The air fryer relies on the circulation of hot air to cook and brown food, a process known as the Maillard effect. This chemical reaction requires adequate airflow to achieve the desired crispiness. When the basket is too full, the air cannot circulate freely, leading to uneven cooking and soggy food.

To avoid basket overcrowding, it is recommended to cook in batches. While it may be tempting to stack or squish food to cook more at once, this will compromise the quality of the results. By cooking smaller batches, you allow for better airflow, ensuring that the hot air reaches all surfaces of the food. This results in evenly cooked and crispy food.

The basket size of most air fryers accommodates approximately two servings of meat or fish, or four servings of a vegetable side. For larger quantities, it is best to cook in multiple batches rather than overcrowding the basket. This additional step ensures that your food cooks faster and more efficiently.

Additionally, it is important to avoid placing the air fryer too close to walls or cabinets. The appliance requires proper space and airflow to function optimally. It is recommended to allow at least five inches of space on all sides of the air fryer during use. This ensures that the hot air can circulate effectively, maximizing the crisping effect.

In summary, to achieve the best results with your air fryer, avoid overcrowding the basket. Cook in batches, allowing for adequate airflow and even cooking. By following this simple tip, you'll ensure your food turns out crispy and delicious every time.

Temperature and timing

The key to achieving crispiness in an air fryer lies in its ability to circulate hot air efficiently. The powerful fan in an air fryer ensures constant airflow above, below, and around the food, which is critical for even heating and moisture evaporation, resulting in a crispy texture. Therefore, it is crucial to avoid overcrowding the air fryer basket to allow for adequate airflow. Leaving sufficient space between individual items ensures that air can circulate freely, cooking the food evenly and preventing soft or undercooked spots caused by overlapping pieces.

Additionally, the amount of oil used in an air fryer can impact the crispiness of the final product. While air fryers require significantly less oil than traditional frying methods, a small amount of oil is still beneficial for optimal results. A thin layer of oil on the food ensures good browning and even roasting. However, it is important not to overuse oil, as this can lead to sogginess. A drizzle or a quick spritz of oil is usually sufficient to achieve the desired crispiness.

It is worth noting that certain types of food are more suitable for air frying than others. "Dry" foods, such as French fries, meats, vegetables, breaded items, and frozen foods, tend to yield better results in an air fryer. On the other hand, "wet" foods, such as battered fish, doughnuts, and onion rings, may not produce the desired crispiness and are better suited for deep-fat frying.

Lastly, it is important to be mindful of the size and capacity of your air fryer when preparing larger items. While air fryers are excellent for cooking smaller portions, they may not be ideal for large roasts or whole chickens, as they may not fit properly and could lead to uneven cooking.

Frequently asked questions