You cannot run a fish and chip shop without frying oil in tip top condition. After all, our favourite fish and chips have to have that crisp, golden texture.
There are enemies of frying oil that can degrade it, reducing its longevity and causing havoc with the foods it contains. Identifying the culprits that are causing breakdown is the most important step in ensuring proper maintenance of your cooking oil and enhancing food quality. The results are happier customers and the ability to maximise profits by enabling your oils to last longer.
Here’s a look at the six enemies of frying oil that might be costing you that return customer.
When edible oil reacts with atmospheric oxygen, it forms hydroperoxides through the process of oxidation. The oxidation method is accelerated by light and heat. When the hydroperoxides decompose, they negatively affect the flavour and decreases the oil quality. Thermal oxidation boosts lipid peroxidation and causes chemical changes in cooking oil.
What’s this all mean in the kitchen?
Since oxidation releases foul odours and affects flavour, nutritional values, and health benefits. It is essential to refill the pan with oil just before a frying shift; you do not want more oil sitting in your pan when it will not be used immediately.
Topping up your pans with oil by a minimum of 1/3 a day will mean oxidation will be under control, so it will not be a problem.
Many would say to limit exposure to air by covering the fryer when not in use; you cannot remove oxygen from the pan this way although it would be a good idea to use lids to reduce foreign bodies falling into your pan.
Carbon build-up from food particles is also one of the top prohibitors of oil longevity. Food pieces are likely to break down and fall to the bottom of the fryer. If you continue using the same oil to fry various batches of food, then they will transfer different flavours and aromas. When the carbon burns, it causes rancidity. The excess coating in fried foods can also cause foaming on the surface.
The best preventative measure (and one of the easiest) is to sieve the crumbs whenever they occur so that they do not remain in the oil and transfer unwanted flavours. While frequent frying will cause the oil to eventually breakdown, regular filtering will extend its shelf life. Another measure that you can take to keep your oil fresh is to use quality oils that have a higher smoke point. The oil should also be designed specifically for deep frying.
Did you know that Salt is one of the most common enemies of frying oil? During the frying process, salt acts as a catalyst and accelerates oxidation. This causes the oil to become darker in colour and release off-flavours, which affects the taste of the food. Salted products also release water and cause foam formation that can cause oil breakdown. Salt can also act as an impurity and lower the smoke point, which in turn degrades oil and shortens its life.
To prevent oil degradation, it is ideal to avoid adding salt before frying. Make sure you fry to the crisp level you want, and don’t try to refry foods after adding salt.
We all know from chemistry that water and oil do not mix. During the frying process, heat causes food to release moisture and result in oil decomposition. Since foods absorb the oil, its degradation has adverse effects on the final properties that the food will have, including the nutrition and shelf life.
With frequent usage, eventually, your oil will breakdown. When steam escapes during frying, it causes foaming and affects the flavour and the quality of your food. You can easily remedy the situation by following best practices, avoid overcrowding the pan and before frying fish, make sure the fish is not wet, and don’t fry at too low of a temperature.
Store liquid oil away from direct sunlight. Light accelerates chemical reactions, including degradation of oil. When the fat molecules breakdown they cause the oil to go rancid. There are some specific oils such as rapeseed oil with unique chemical structures that make them more vulnerable to going rancid and exuding an off smell. The trick to increasing the longevity of your frying oil is to avoid those stored in clear containers. If your favourite oil always comes in a transparent bottle then store in a cool, dark pantry and keep the caps tight.
Extreme temperatures break down frying oil faster, and in most cases even when your food is crispy on the outside, it tends to be overcooked on the inside. The solution for preventing breakdown caused by heat is to keep your cooking oil at its ideal frying temperature by independently checking pan temperatures regularly. Any fluctuation from the display temperature will give you inconsistent fried food.