Humankind has been frying food in fat or oil for centuries. As far back as the 2nd millennium BC in Canaan, deep-fried dough known as Zalabiyeh was a favorite on the local menu.
History also records the frying of food in olive oil back to Classical Greece from about the 5th century BCE, before it spread across the rest of Europe and then out into the world.
And while people have been frying for millennia, frying in fat or oil has come under scrutiny in recent years for being “unhealthy.” That statement needs further explanation because it is not always true. Frying in fat or oil is actually an excellent method for preparing food, but you have to make sure you have all the right conditions and use a suitable oil.
It is indeed true that when ignoring some basic rules about the process, deep fat frying can be harmful to your health and that is exactly why Dipo developed cutting-edge technology across our line fryers to ensure that it’s easier for chefs in kitchens around the world to fry right.
So, What Can Go Wrong?
This is not an easy short answer, so you either scroll down to the conclusion or you can settle into your seat, pour yourself a nice cup of coffee, and get to the bottom of this.
To answer the question we need to look at the process of deep-frying itself.
When food is submerged in hot fat or oil, it cooks quite quickly and is actually an excellent way of preparing food. The reason why is that the food cooks from the outside in and after searing the outer layer moisture is retained inside whatever food you’re cooking. This can be meat, fish, vegetables, dough, or whatever else you’re cooking up for your guests.
Not All Oils Are Created Equal
An important thing to remember is that different foods cook at different temperatures and the quality of the oil should match whatever your dish requires. For example, not all oils are suitable for frying at 170 or 180°C. Some foods fry better at temperatures as low as 150°C. So, it’s important to find out what temperature works best with whatever food you are preparing.
Another thing to keep in mind is that the quality of the fat or oil that you are using is crucial — as is setting the correct temperature to whatever it is you wish to fry.
All that sounds simple enough, so how did deep fat frying get such a bad reputation?
With the arrival of the freezer, it was easy for manufacturers to supply you with pre-cooked food that you simply needed to plop in the oil and fry away to your stomach’s content.
While it sounds convenient (it is!), the problem is that these deep-frozen products contain substantial amounts of frozen moisture. And if there are two things that hot oil doesn’t like, it’s extreme cold and its arch-nemesis, water.
But when you drop that portion of frozen chicken wings into your fryer oil not only are you adding moisture to the oil but, depending on the portion size, cause the oil temperature to drop 20 to 30 degrees.
The Good, the Bad, and The Nasty Stuff
What happens next is what gives frying in fat a bad reputation. By dropping the temperature of your oil, the food surface doesn’t have enough time to seal enough so the oil penetrates your food and the moisture inside your food, which keeps it yummy, can escape. The result is a dry piece of chicken with lots of oil content in the crust. This doesn’t only happen to chicken, it’s the same for other types of food, too.
But there is more. Many deep-fried foods, such as chicken, are coated with a thick batter or a breadcrumb crust. When you cook foods like that in hot oil some of the batter of breadcrumbs will come loose and drift down to the bottom of whatever you’re using to fry your food, where it stays until you clean or replace the oil.
With the arrival of the freezer, it was easy for manufacturers to supply you with pre-cooked food that you simply needed to plop in the oil and fry away to your stomach’s content.
With the arrival of the freezer, it was easy for manufacturers to supply you with pre-cooked food that you simply needed to plop in the oil and fry away to your stomach’s content.
When the particles continue to stay in the bottom, they become burnt and become something quite nasty. There is also an effect on the flavor. If you’re deep-frying potatoes, for example, and there are remnants of the chicken you previously cooked, well, that’s not good at all for your carefully crafted recipes.
Getting back to the “nasty” stuff, it’s something known as “free radicals” – one of the primary culprits of “unhealthy” frying as high intake of these free radicals can cause serious health problems.
One way that free radicals are formed is when meat is cooked at excessively high temperatures which causes the fat inside the meat to burn. They also come from preservatives that manufacturers use in processed foods. But frying oil can also oxidize under the influence of air, water, and sunlight and become what is called “rancid”.
When this occurs, there is a large number of free radicals released into the oil, and that is very unhealthy.
Unfortunately, it is not commercially viable for restaurants and fry shops to change the oil in their fryers after a few hours of use. While the right thing to do, it would simply make frying too expensive. This is especially true for fast-food restaurants, which are loved for their fried menu items. Optimal changing of oil in their fryers would cause their cuisine to become gourmet priced.
At the time of this writing, one liter of good quality frying oil can cost up to $1.5 USD. Changing that every day, at that price, would add a difficult financial burden to restaurant owners. The standard solution is to use the oil as long as they can.
The Dipo Induction Solution
Over the years, the process of frying, and the deep fryers this popular style of cooking is done in, has not changed much at all. Sure, they became fancier with programmable timers and even some modest filtering options, but there has been no significant change such as what we had when we went from the landline phone to a mobile or from a mobile to a smartphone.
Those were huge transformations that dramatically changed our way of communicating. Fryers, however, still fry the same way they have for centuries.
Until now.
Dipo Induction was the very first company that understood that using inductive technology to heat up the oil in the fryer saves energy and time. But we weren’t satisfied with doing just that.
For as long as we remember, fryers have been heated by gas or conventional electric heating elements which are neither environmentally-friendly nor efficient. Far from it actually.
Ever since induction technology was invented, studies around the world have consistently shown that efficiency was the highest of all the different cooking methods. Compare 35% for gas and 65% for radiant heat with 94% for induction and you know why many governments around the world are actively promoting and subsidizing the switch from gas and conventional electric to induction appliances.
But What About Fryers?
Dipo has been developing and producing induction technology for professional use for more than 20 years. Professional appliances have a totally different demand than your home range top or fryer. Professional fryers have to work nonstop at maximum capacity. Cleaning and replacing the oil must be quick and easy because time is money for any business large or small.
Dipo understands this dilemma and invested heavily in developing an innovative new range of fryers in collaboration with chefs and technology institutes. The end result of our joint efforts has revolutionized the fryer forever.
The “Cool Zone” is Not so Cool
In recent years, many fryer brands have opted to create a “cool zone” in their fryers. They even promote this as being a “good thing” or beneficial to the fryer.
Actually, what they often conceal is that they created a cool zone to prevent all the food particles that drift to the bottom of the fryer from burning. And, while some do a better job than others, nobody gets it right.
The simple fact is that food is still collecting at the bottom and, while maybe a bit slower than before, is still burning while releasing free radicals. This happens even if the food particles sit on the bottom for as little as one hour. To be quite succinct, “cool zones” are, by their very nature, little more than a band-aid, unable to solve the real problem.
The Problem with Abundance
Then there is the issue that a commercial fryer in any busy professional kitchen must be able to handle large amounts of food in a short time.
On major problem is that handling large amounts of frozen food makes the oil temperature rapidly drop, which results in a badly fried end product that is often soaked with oil.
Most manufacturers attempted to overcome these problems by doing two things: First, they make the content of the pan so large that the sheer volume of oil retains a lot of energy. The “logic” here is that when a few pounds of frozen produce is dropped in the oil, the sheer mass of oil can sort of keep an acceptable average temperature.
One major problem is that handling large amounts of frozen food makes the oil temperature rapidly drop, which results in a badly fried end product that is often soaked with oil.
The second “solution” is to build the fryer with an extremely-high heating capacity with either huge gas burners or powerful heating elements to get the oil back to the right hot temperature again as quickly as possible. This is called the “recovery time” and is often expressed by a certain number of kilos a fryer can handle per hour.
There are actually government test methods to verify the recovery time specs, but by doing this the efficiency of the fryer, which is already the lowest of all kitchen appliances, will be reduced even more. As you can imagine, there is a considerable difference in the energy needed to heat 15 liters or 30 liters (4 or 8 gallons).
As we already know, the efficiency of gas burners and heating elements is already problematic by the rudimentary laws of physics, so by adding more power, things actually go from bad to worse on the efficiency ratings.
The Dipo Difference
Here is why we at Dipo have revolutionized the fryer in the same way the smartphone revolution changed the way we stay in touch with each other in our modern era.
By design, Dipo fry pans have a smaller oil content yet still reach the same frying capacity per hour. And this is done with incredible efficiency while using between 40 and 50% less oil in the fryer.
With oil costing $1.5 USD per liter that adds up to significant savings to start with. Less oil means less heat-up time and with a super-efficient induction heating system, the recovery time is done at industry-leading speeds as well.
Dipo fry pans are heated by the very best induction technology available in the world with efficiency ratings of 92%. In your gas fryer, you get 3400 watts of energy into the oil out of every 10,000 Watts you put in. In other words, Dipo’s induction technology heats up the same amount of oil in the same time with less than half of that energy. That’s another huge saving of your hard-earned money but it also contributes to a much cleaner less wasteful process.
Another great benefit is that with induction, which emits no heat, there is no longer a stinking hot environment in your kitchen. Since our system burns no fossil fuel, there is no need to rely on fans and air conditioning units to cool down your kitchen from excess heat. And that, of course, saves more money, too.
To put all this in perspective, even the best conventional heating element is using about 25% more energy when compared to Dipo induction technology.
The Smart Filter
Remember the pesky food particles we talked about earlier? The excess batter or crumbs that inevitably break off from the food being cooked and drift down to the bottom of the fryer and burn? Dipo fryers have solved that as well with the use of a patented smart filter and pump system that removes any particles that may fall to the bottom during frying.
Yes, you read it correctly, our system filters all that off while you’re doing your frying. Quite simply, what doesn’t end up on the bottom of the fryer, doesn’t burn.
While all this sounds simple enough, it is the first time in the history of the fryer that this has been done.
Dipo Fryers use a patented system consisting of a high-temperature oil pump, a waste collector, a set of fine mesh filters and another one that spins and cleans the oil. (“Centrifugal force filter” for the nerds among you).
How it Works – Three’s a Charm
After you switch on your fryer the induction coil instantaneously begins heating the oil. In a normal fry pan the oil that is heated wants to rise up to the surface creating a natural circulation called convection. Convection, however, is very inefficient.
To solve this, we added a pump to circulate the oil at such a speed that the heating is done faster and more evenly, and quicker.
The oil is drawn in by the pump from the bottom of the pan, with suction that is strong enough to remove any debris or food particles that are either floating in the oil or have drifted to the bottom. The oil then passes to a “waste collector”, where the largest particles are gathered in a container that can easily be removed at any time and emptied into your food waste bin.
After going through the waste collector, the oil enters a stainless steel filter with 3 different mesh seizing plates This combined trio of filters not only makes sure that even the smallest of particles are removed but they also ensure that the flow of oil is not reduced – so the heat remains consistent.
At this point, your oil is already much cleaner than in any regular fryer but there is still a risk that minuscule water particles from the ice of your frozen food are in the oil. Everybody who has used a fryer knows that clean oil is clear, you can see the bottom of your pan. “Dirty” oil, on the other hand, is not only darker but often cloudy.
To overcome this and to make sure that your oil is kept in the best possible condition we added a third cleaning step. The hot oil is at this point a very thin liquid and is pumped with pressure through a small hole making the filter cartridge spin at very high speeds. Particles (moisture and solid micro-particles) are heavy and fly to the outside of the filter where they are collected and separated from the clean oil that is continuously being pumped back into the pan.
Imagine the centrifugal effect from your spin dryer or washing machine or in a more fun way is to imagine the amusement park ride called the Gravitron where you lean against the wall and when it starts spinning you stick to it by the force of gravity to the point where you can hardly move your head forward.
Well, that’s exactly what happens to the pollutants in your oil, they stick to the filter wall, never to be seen again until you pull out the waste cartridge and dump it in the garbage bin.
With an oil content of 12 liters in the pan and 3 liters in the pump and filters, tests have shown that you can extend the usage of your oil almost endlessly.
By removing the waste cartridge once per day you remove 1 liter of oil. That minimal amount is then replaced with clean, fresh oil.
The second filter is cleaned every three days, the content of that is also one liter so on every 3rd day you remove and replace 2 liters. The third filter is replaced only once per month and contains only 0.5 liters.
To make it a bit simpler, all you do is replace 1 liter on Monday and Tuesday and 2 liters on Wednesday. That makes 4 liters or 27% of the total oil volume in the fryer system. On Thursday and Friday, you again replace 1 liter and on Saturday it’s 2 liters again. If you’ll allow me to save you the trouble of doing the math: in one week you replaced 60% of the 15 liters of your total fryer content, which is only 9 liters. Yes, 9 liters.
With this system you never replace all the oil, you simply keep replenishing what little has been removed by the filters. This is a 5-minute job and doesn’t require tools or extensive cleaning. If you compare that to current fryers on the market cooking the same amount of food, you would have to replace the total content of your oil at least once a week. And on the last day, you are at serious risk of having a dark cloudy oil that is full of free radicals. And that’s no good at all.
Most fryers use between 25 and 30 liters. By using the Dipo fryer system you can save 16 to 21 liters of oil per week @ $1.5 USD per liter. That adds up to some pretty impressive savings to your bottom line.
Plus you have saved another 35-65% on your energy bill.
For high-volume kitchens with several fryers running continuously during business hours, this can easily lead to savings of thousands of dollars per year.
As you can imagine, that’s enough to pay for your complete new fryer and have money to spare and do something nice – like give yourself and the staff a raise perhaps.
Smart Timers and Smart Sensors
Fitted with smart timers, intuitive temperature sensors, and an optional sensor that checks your oil quality, all of this adds up to even more savings because the Dipo Induction fryer itself tells you exactly when you reached the point of needing to replenish some of your oil content. Triple safety in electronics and very accurate fast temperature control is our standard.
While it took us a while to get here, we are sure you’ll agree there simply is no better choice when buying a professional fryer than the revolutionary technology the engineers at Dipo have created.
Conclusion
Dipo fryers are saving you money by being super-fast and super-efficient. They also help you save money on oil simply because you do not have to change your entire pan content ever again. They save energy and the environment. No CO2 or NOx gasses enter the atmosphere. Your kitchen will be less hot, it will smell better and be an overall more pleasant environment for you and your staff to work in. Safe too: no gas or open fire with hot oils and because of our triple safety we ensure you that the oil never gets too hot to self-ignite.
Written by Martin Vermeulen
