Frying with Oil

The deep frying technique is shunned by some due to the perception that deep-fried food is unhealthy, and that the cooking process can release oily fumes which make the kitchen dirty.

However, with care, it is possible to minimize these disadvantages.

Oil is a good conductor of heat, allowing the food to be cooked in high heat. As the food item is immersed, it is cooked from all sides. The bubbles created when moisture interacts with the oil help to create interesting crispy textures.

For deep frying in Asian cooking, we don’t bother about measuring the temperature of the oil. We just watch for signs like ‘shimmering in the oil’ or, often, we just put in a bit of food or poke a chopstick in and look out for bubbles. If the oil is smoky, it is over heated. With time, the cook will get a good sense from looking at the oil and hearing the sound to know if the oil is properly heated. I put my hand a few inches above the oil (I don’t recommend dipping it in!) to sense the heat. When it is uncomfortably hot, I know the oil is ready.

When the oil is hot enough, you hear a sizzling sound and see bubbles. That is air and water interacting with the hot oil. The bubbles form a cushion around the food, resulting in minimal absorption of oil and creating a crisped crust from the air pressure. Thus, if the oil is not hot enough, you have a ‘soaking in oil' effect. Likewise, if you leave the food in there for too long, after the moisture has escaped from the food, the vacuum created will suck in the oil. The same thing happens if you do not drain fried food properly.

How long should you leave the food to cook in the oil? Once the sizzling slows down, it is a sign that the moisture has escaped from the food. And if you have done it right, it should be crispy by then.

As the food is being deep fried, bits of it will remain in the oil and compete for the heat as you fry a new batch. These bits will also be burnt in the oil, making your food taste bitter. So, after every batch of frying, the oil should be dredged. I should add that the electric fryer, which is common in commercial use, is better than using a wok over a stove fire. It is more consistent and efficient and I recommend using it if you deep fry your food regularly.

There is the need to drain the oil off deep fried food. It comes after frying and often, a careless cook will do it as an afterthought or neglect the step altogether. The best way to drain oil is to use a colander or strainer with large gaps and leave the fried food there with a bowl underneath it to collect the dripping oil.

Pan-searing uses direct contact of the food with the hot metal of the wok or pan to ensure that high heat is quickly transferred to the surface of the food to cook it. This is the technique for cooking steaks. The marinate or sauce will stay on the food, forming a flavourful crust, in contrast to dissipation into the oil through deep-frying. The Fried Assam Prawn recipe uses this technique.

This is a good alternative to deep frying when you want to control the amount of oil used or when you are cooking a small amount of food and do not want to bother with setting up for deep-frying.

Shallow frying in a pan or wok is a good way of frying fish and this is the technique used for Chili Fish. Turn the fish at the half-way mark to ensure evenness in the cooking.