In a flame ionization of the air atoms will occur, because the temperature is high enough for the atoms to be wrong in themselves, and in the cracks of the electrons. Therefore, the amount of ionization in the flame depends on the temperature. (There are other mechanisms can lead to ionization. For example, in the lightning and strong electrical currents instagram. In the ionosphere, the sunlight caused to instagram.) The fact is that there is an open flame is a plasma, only if it’s very, very cold. A burst of flame at low temperatures, it does not contain enough ionization to the plasma. On the other hand, a high temperature flame is indeed enough freedom of electrons and ions to occur, such as in a plasma.
For example, in a regular wax candle is a flame that burns at 1,500 degrees Celsius, which is enough to make a lot of ions. Thus, the flame of the candle is not in plasma. Please keep in mind that it’s bright red-orange to yellow colour, which we can see, in the flames of the fire, which is in a plasma.