Vacuum and pressure frying fruits and vegetables

Summary

In this video, the process of vacuum frying is explored as a technique that allows for frying fruits and vegetables at lower temperatures by reducing pressure in the cooking vessel. This method prevents the outside of the food from burning while ensuring the inside remains moist. The presenter demonstrates how vacuum frying compares with traditional and pressure frying, particularly using bananas as an example. The video also covers the setup, including modifications to a pressure cooker and the use of a vacuum pump, showcasing the advantages of vacuum frying in preserving flavor and texture while preventing overcooking.

Takeaways

• 😀 Vacuum frying is a technique that involves lowering the pressure in a pot to change the boiling point of water, allowing for frying at lower temperatures.
• 😀 In traditional deep frying, hot oil replaces some of the food's water and cooks it, but this doesn't work well for fruits or vegetables that contain a lot of water.
• 😀 Vacuum frying allows food to be fried at lower temperatures, which helps prevent the outside from scorching while still reducing moisture inside the food.
• 😀 The boiling point of water is lowered in a vacuum, similar to high-altitude cooking, requiring adjustments to cooking time and pressure.
• 😀 Vacuum fried bananas have a crisp exterior and moist interior, maintaining flavor without burning or overcooking, which is not the case with traditional frying.
• 😀 Pressure frying, commonly used in fast food restaurants for fried chicken, involves cooking food under higher pressure to achieve a different texture and moisture level.
• 😀 The vacuum fried bananas are the crispiest and least burnt, while normal fried bananas are soft and squishy, and pressure fried bananas are crisp on the outside but soft inside.
• 😀 The vacuum frying process requires a vacuum pump, a cold trap to capture water vapor, and precise temperature control, such as using an induction cooktop.
• 😀 A commercial stainless steel pressure cooker can be modified to create a vacuum fryer by removing the handle and safety features, along with making adjustments to the lid seal.
• 😀 While vacuum frying at home is possible, achieving ideal results without specialized equipment like dry ice for cold traps might require some adjustments, but it can still be done effectively.

Q & A

What is vacuum frying and how does it differ from traditional deep fat frying?

Vacuum frying is a method where food is fried at lower pressures, reducing the boiling point of water, which prevents scorching while maintaining moisture inside. Unlike traditional deep fat frying, which involves frying food in hot oil at high pressure, vacuum frying uses lower temperatures and pressure to achieve a different texture and moisture balance.

Why is vacuum frying particularly useful for frying fruits and vegetables?

Fruits and vegetables contain a high amount of water. Frying them at high temperatures, like in traditional deep frying, would result in a burnt exterior and a still-moist interior. Vacuum frying allows for a lower cooking temperature, preventing scorching while extracting water without compromising the texture or moisture of the food.

How does the vacuum frying process help maintain the flavor and texture of food?

The vacuum frying process uses lower temperatures to remove water from the food, which preserves its natural flavor. This method avoids the need for excessive browning or overcooking, maintaining a fresh, uncooked flavor and a firm texture, unlike high-temperature methods that might alter the food's inherent taste.

What are the key differences in the results of vacuum fried, atmospheric fried, and pressure fried bananas?

Vacuum fried bananas have a firm texture with a crispy exterior and moist interior, while atmospheric fried bananas are softer and have a thin, almost burned outer skin. Pressure fried bananas, on the other hand, have a crispy outer layer but are softer on the inside due to higher pressure and temperature.

What challenges did the author face when adapting the pressure cooker for vacuum frying?

The author faced an issue with the seal in the pressure cooker. The seal, which is designed to work under pressure, would collapse under a vacuum. To solve this, the author used stainless steel welding rod to maintain the seal's integrity, but after multiple uses, oil around the lid caused the seal to slip again.

How did the author prevent water from damaging the vacuum pump during the frying process?

The author used a cold trap, a thermos filled with denatured alcohol and dry ice, to capture the water evaporated during the vacuum frying process. This prevented the water from reaching and potentially damaging the vacuum pump.

What is the role of the induction cooktop in the vacuum frying setup?

The induction cooktop was used to precisely control the temperature of the oil during vacuum frying. It allowed the author to set and maintain a consistent temperature for the frying process, ensuring optimal cooking conditions.

What is the significance of using different pressures and temperatures for the various frying methods?

Different pressures and temperatures are crucial for controlling the boiling point of water inside the food. By adjusting these factors, the author can alter the cooking time and texture of the food. Vacuum frying uses lower temperatures, pressure frying uses higher temperatures, and atmospheric frying uses typical frying temperatures.

Why does the author believe the vacuum frying system could be practical for home use?

The author suggests that the vacuum frying system could be practical for home use because it doesn't necessarily require dry ice for the cold trap and could be achieved with a less expensive vacuum pump and a simpler cold trap. This makes the process more accessible while still yielding good results.

How does the vacuum frying technique compare to fast food restaurant methods, specifically for frying chicken?

The author notes that vacuum frying shares similarities with pressure frying, a technique used in fast food restaurants for frying chicken. Pressure frying helps cook food quickly while keeping it crispy, which is why the author suggests the technique could be useful for fast food items, with similar texture and moisture control benefits.