Whether mixing oils raises the temperature of dillenia?

From textbooks, on the advice of colleagues or based on personal experience, we know for sure: mixing oils (such as butter and refined) can increase the temperature of Smoking.
The idea is very attractive: butter has a stunning taste and aroma, but at low temperatures burns. While refined oils, inferior in taste, allow you to fry anything and anything. By placing a mixture of oils in one pan, we can cook at high temperature, preserving the taste.
But is that really the case? Let's find out.
Test.
So, let's start with the fact that we describe the essence of the experience.
We will use a cast iron pan with a little butter. To avoid heating individual parts (and we know about the thermal conductivity of the metal), we will constantly rotate it.
The first signs of Smoking appeared at 190.(5) with degrees. At 204.(4) from the pan already smoked with might and main, and at 232. (2) We had to remove it from the stove, turn on the hood to the full and open all the Windows.
Then we took grape seed oil, known for its high smoke temperature.
it lasted until 254.(4) S
For the final test, we mixed both oils in a frying pan. If the theory is correct, the smoke point would be somewhere between 190.(5) and 254.(4) degrees.
Alas. The mixture began to smoke at 190.(5) PP.
Yes, that's right. The smoke temperature of the mixture is equal to the lowest smoke temperature of a single oil.
Why is this happening? Let's face it.
The oil consists of three elements:
Fat: of course, most of the oil is fat. about 80-83 %, depending on the brand and manufacturer. Fat, in turn, does not consist of the same type of molecules, and is a homogeneous mixture of different, each of which has a unique shape and size.
Water: most oils contain about 15 % water.
Proteins: in Addition to a small amount of milk sugars and mineral elements, the remaining few percent of the mass is occupied by proteins - they can be observed in the form of foam on melted butter. And they determine the taste and aroma of the oil.
So what happens when the oil is heated in a frying pan? At low temperatures, it softens. Since each type of fat molecules has its own melting point-the oil melts gradually, passing into the liquid phase between 32 and 35 C. at this stage, the aqueous phase is separated and forms a distinct layer on top of which the fat floats.
After the water has evaporated, fats and proteins remain. The latter are denatured and destroyed by heat. Smoke point 190. (5) C is the temperature at which they burn. And regardless of whether they are in butter or in a mixture, it will still happen.
Ghee oil, which consists entirely of fats, has a smoke temperature of 260 C, but, alas, does not have the same bright taste.
Yes, using a mixture of oils has its advantages: because of the lower protein content, it will not be so bitter.
In the end, it all depends on what you want to get in the end. For example, to achieve a stunning crust, frying steak or pork chops, we always use butter.
While cooking fish or chicken, we prefer refined, as a bitter taste of cream just spoil everything.
the original article in English:
http://www.seriouseats.com