Dr Hector Perera London
Back home in Sri Lanka cooking was mainly done by servants or by “Kussi Ammas” but now they are gold dust as they have gone abroad for better paid jobs. They knew cooking by sheer experience not by reading internet or papers as they are not much educated. In the past they mainly cooked on firewood stoves than on gas and electric cookers. It was not easy to cook with such traditionally old methods compared to modern facilities such as with gas and electric cookers, ovens and microwaves. The firewood stove kitchens are always quite hot, smoky and filled with smoke dust and ashes when they cook rice and curries, apart from that the smell of curries also can be easily detected if anyone walk into a kitchen. Now I am wondering how did they managed to cook such tasty food with such difficult conditions.
Some British TV judges just show facial expressions
If anybody watched the British TV cooking programmes they would realise that the kitchens are really hot, gas cookers are always on full blasting fire for no reason and sometimes full of cooking aroma because they always keep on stirring what was cooking just like “Kussi Ammas” in Sri Lanka. That really reminds our good old servants did to keep on stirring constantly, tasting the curries several times. In the TV, people who cook sometimes run all over the place in a hurry just like headless chickens for no reasons, perhaps trying to get more attention from the judges and viewers for their actions and reactions. Sometimes the so called judges show lots of facial expressions and just shout out the time left for cooking than watching the good techniques in cooking and any mistakes the competitors do while cooking. Later they judge their cooking only by the taste of food than anything else.
A bit of science in cooking
For two bodies at different temperatures, heat will flow from hotter to the colder until their temperatures become the same or until thermal equilibrium is reached. When you increase the temperature of a gas, the speed of its molecules will increase as well. This leads to the molecules impacting against each other more often and hitting the container more often, which, by its very definition, is an increase in pressure. This is known as Gay-Lussac’s law. We can often see Gay-Lussac’s law in action.
If the temperature of a container is decreased, the pressure decreases. These kind of scientific ideas are applied in my scientific energy saving cooking. In my method of cooking, I am trying to make use of those well-established scientific gas laws. If my ideas are wrong then those gas laws would have been disproved many years ago.
I have noticed when some people cook things like chicken curry or even a vegetable curries, they always stir it up with a spoon in order to mix them or to turn them around. The point is when we keep on stirring a boiling chicken curry or a vegetable curry, a stream of molecular vapour of spices; ingredients and water escape at the same time and likely to deposit some of it on the person who was stirring then most of it escape into the air. That means as soon as the lid is opened the pressure is released so the trapped gas molecules are free to escape due to gain of kinetic energy. Some of those molecules have a speed more than the speed of a jumbo jet due to absorption of heat that means gas molecules move due to kinetic energy. This is where this curry cologne comes from, I call this curry cologne or spicy cologne or sometimes chicken cologne as the vapour comes from different sources. It’s not just the vapour of one spice but a mixture of spices so there is no particular name for the vapour and I call it by those names.
The speed of the molecules in a gas is proportional to the temperature and is inversely proportional to molar mass of the gas. In other words, as the temperature of a sample of gas is increased, the molecules speed up and the root mean square molecular speed increases as a result.
The metal cooking containers absorb some heat due to it’s thermal capacity but any excess heat get lost to the surrounding. Earthen ware cooking pots absorb any heat very slowly as they are bad conductors of heat that means cooking on firewood stoves is a huge waste of energy. Some of the heat pass on to the cooking things inside the cooking pan due to convection currents. One must realise the cooking substances are bad conductors of heat so one must allow sometime for these reactions to take place. Once the ingredients are mixed with chicken or vegetables inside the cooking pan, convection currents pass the heat on to them quite slowly as they are bad conductors. We can increase the rate of convection currents by increasing the pressure inside the container and that is why I close the lid while cooking. The ingredients tend to absorb into chicken or vegetables then some other substances ooze out while some get absorbed. One must realise these reactions take time so it needs time for these reactions. If we disturb these reactions by constantly stirring, it certainly disturb these reactions. In that case would you keep on stirring a pot of rice while cooking? No wonder sometimes they go pear shaped and ends up with burnt out rice or “dankuda”.
Sri Lanka servants knew the technique of cooking different things due to years of experience and that is why they cook very tasty food. If one keeps on stirring, some of the vaporised ingredients escape into the air and some of them get deposited on the person who cooks and some got inhaled by the person who cooks. The escaped oily ingredients would deposit anywhere including on the nearby cupboards then on the clothes, hands, face and on the hair of the person who cooks. No wonder they really smell of cooking aroma due to these invisible deposits.
This kind of inexperience cooking is most evidently seen in some British TV cooking programmes. They get showered with cooking aroma while cooking and the judges just ignore those actions. If the contestants or the person who cooks a chicken curry understood the science behind the cooking then the things would be different. No wonder their cooking hardly save any energy and would not know how to stop any cooking aroma depositing on them. One other worst thing is they constantly inhale the cooking aroma. The scientist have proved the long term subject to cooking aroma leads to cardiovascular and pulmonary diseases. Some professional chefs suffer from these conditions but they are unaware of the dangers of inhaling cooking aroma.
Most TV chefs are good jokers and jugglers
This is what I insist that one must have some scientific knowledge of cooking. No point of just adding this and that hastily, stirring them carelessly and sometimes set fire to the cooking aroma. Some so called famous chef, virtually swear while cooking, set fire to cooking aroma or keep on joking and some others are good jugglers, How would they are given a priority in British TV cooking programmes? Perhaps the cooking programme producers and organisers themselves have no scientific knowledge in cooking. As someone said “Keep on cooking” but that would not help to educate general public. That kind of cooking waste energy and most people would stick to eating more junk food than cooking at home because they think cooking is such a difficult task.
My cooking demonstrations in TVs
Dr Hector Perera