If you are someone who understands why there is more heat in a block of ice than in a candle flame, please skip down to the recipe section – cooking the dish is a simple series of steps and you will enjoy it, especially if you like chicken.
Also, I think it is delicious and as a bonus, pretty efficient in the use of energy.
For many people, there is often a little confusion between the terms heat and temperature. It is best demonstrated by a simple experiment.
In a hot oven, operating at, say, around 150°C, it is quite comfortable to put your hand in the heated air inside (without touching any parts of the oven) and you can probably hold your hand in there for some seconds.
However, from experience, you would know that it is almost impossible to leave a finger in boiling water for a full second without causing some painful damage – so please don’t do this. Yet the temperature of boiling water is only 100°C.
The reason is because there is a fundamental difference between the terms heat and temperature – and this difference is also highlighted in the following recipe where it will be demonstrated that much less energy can be utilised to cook chicken compared to using an oven.
Heat can be defined as the total amount of kinetic energy in a system – and a system consists of the amount of atoms and molecules within the confines of the system (or container).
Kinetic energy is simply the energy a body possesses by virtue of being in motion – the faster the motion of the atoms and molecules, the more kinetic energy they have and therefore the more heat they also have.
Note that heat is classically measured in joules. Although people commonly think they are measuring heat by using thermometers, technically that is wrong as what they are measuring is actually the temperature, a vastly different concept.
Temperature is defined as the average kinetic energy of the atoms and molecules within the confines of a system. So if matter (ie. atoms and molecules) is denser in a system, there will be more heat present in the denser medium compared to a system where matter is less dense, even if the temperature is the same. Therefore, water at 100°C has very much more heat than the air in an oven at 100°C.
So that explains why there is more heat in a block of ice than a candle flame. Even though the molecules in a frozen block of ice are moving more slowly, there is still more kinetic energy in the ice than the candle flame, simply because there are more molecules of water in a block of ice at 0°C.
And now you also understand why your hand can remain in an oven where the temperature is hotter than boiling water – the air in an oven simply has much less heat than boiling water.
This also explains why good quality cookware tends to be thicker or use better materials in their construction – it is simply to consistently hold and distribute heat better across the cooking surfaces of the pots and pans. Otherwise, there may be irregular hotspots on the surfaces which can result in uneven cooking.
Basically, temperature has never ever cooked anything – it is the heat in matter raised to cooking temperatures that actually cooks food.
Also, two unequal masses in contact at the same temperature can be in heat equilibrium (a very interesting situation as the kinetic energy actually bounces invisibly between the two masses) but any two masses of any size with different temperatures touching each other can never be in equilibrium – the higher temperature will always flow from the hotter mass to the cooler mass in something called a temperature gradient.
This is how frying pans work, for example – the heat is transferred from the hot metal to the ingredients causing them to sear. But it also applies to other materials as well and can be a really cool and efficient way to cook our chicken.
A simple recipe
This is an easy recipe to follow and results in a rather nice variation of Hainan chicken – and it is almost fool-proof. What should be noted is that I have increased the cooking times slightly just in case the cookware you use has different thermal characteristics from my home cookware.
This is because raw chicken is a common vector for rather nasty bacteria such as enterococcus, salmonella enteritidis, staphylococcus aureus, campylobacter jejuni and listeria monocytogenes so for safety, it is better to overcook slightly, just in case – you can adjust the cooking times yourself later once you are comfortable.
If you are interested in the rationale, it is because every part of the chicken must normally reach a temperature of 74°C (and remain at this temperature for a few minutes) before it can be considered safe for eating – this temperature is slightly above the maximum survival range of the known common bacteria in raw chicken.
Actually chicken can also be cooked at a lower temperature but it will have to be maintained at that lower temperature for a much longer period of time. For example, Heston Blumenthal roasts chicken to an internal temperature of only 60°C but it takes almost 4 hours in the oven.
The reason is to do with the second law of thermodynamics as applied to an isolated system (such as a chicken) – it can be expressed as a function of energy, time and pressure.
Simply expressed, it is kinetic energy raised above a certain average temperature (usually 60°C or higher) that cooks food – if this average temperature is lower, it needs more time for a system to attain the total energy needed to kill off all the bacteria and finish the cooking process, assuming air pressure remains the same.
It is the same principle applied by slow cookers and sous vide cooking systems. However, for this recipe, we are using the principle in reverse as we will start from a high temperature and let the temperature gradient do the cooking.
So the first utensil needed is a large saucepan or a big pot with a good lid and which is also sizeable enough to accommodate a whole chicken snugly. Then we need ano-ther smaller pan for the rice, also with a lid – this is to cook the rice which accompanies the chicken.
If you wish, you can just use your normal rice cooker to make the rice but please use the liquid mentioned in the recipe. The last item is something to mince herbs very finely – it can be a keen grater, a pestle and mortar or in my case, an electric chopper. Oh, and you also need a sharp, heavy knife to cut the cooked chicken.
For ingredients, you will need the following for the various stages. Please note that you should prepare the next stage while the previous stage is still cooking.
Stage 1 – Chicken
1 whole chicken, around 1.6kg (to feed 4 persons)
50g ginger, peeled, for seasoning
25g garlic, peeled, for seasoning
50g shallots, peeled, for seasoning
5g salt, for seasoning
35ml water, for seasoning
10-12 whole black peppercorns
5g dried mushrooms (any variety), soaked
cold water, enough to just about cover the chicken in the pot
Stage 2 – Rice
500g long grain rice, rinsed till water runs clear, then drained
20g garlic, peeled and chopped
35g shallots, peeled, thinly sliced
50-70g chicken fat
1 tsp olive oil
1 medium zucchini, sliced into 1cm rings
any other vegetables you like (optional)
900ml chicken stock from Stage 1
Stage 3 – Dipping Sauce
8 tbsp good quality soy sauce
2 tbsp good quality sesame seed oil
4 tbsp Shaoxing rice wine (if not available, some dry sherry is also fine)
4 tbsp Mirin (or some sweet sherry)
30g ginger, peeled, cut into matchsticks
3-4 stalks spring onions, sliced
small bunch fresh coriander leaves, chopped (optional)
5-6 bird’s eye chillies, chopped (optional)
freshly ground black pepper (optional)
Steps for Stage 1
If the chicken is in the fridge, take it out and let it rest till it reaches room temperature – this may take an hour or so. Prepare the herb seasoning by blending the water, shallots, garlic, ginger and salt in an electric chopper or pestle and mortar.
Trim off the excess fat and skin inside the chicken cavity and around the neck. Reserve the fat.
Using a spoon, go under the skin of the chicken and insert some seasoning into the joints between the thighs and legs and also on top of the breasts. Rub the remaining seasoning inside the cavity of the chicken.
Drop the peppercorns and dried mushrooms into the large pot and put the whole chicken inside, breast down. Pour in the cold water until it almost reaches the spine of the chicken – make sure the water can circulate inside the chicken cavity.
Cover the pot and set it on high heat. From this point on, it is important to never open the lid again until the chicken is cooked, otherwise the dish will be ruined.
Watch the lid for steam emission – when the steam starts wheezing out, set a timer and cook for 10 minutes. You should also turn the heat down slightly – the requirement is to maintain a steady (but not excessive) amount of steam emission from the pot.
After 10 minutes of steaming, turn the heat off completely and take the pot off the hob. Do not open the lid. Set a timer for 50 minutes and leave the pot alone while the chicken cooks inside.
After 50 minutes, insert a ladle inside the chicken, remove it from the water (draining out as much water back into the pot as possible) and place it to rest and cool on a chopping board or large plate.
Steps for Stage 2
Cut the reserved chicken fat and skin from Stage 1 into pieces.
Heat at medium high the pan which you intend to cook the rice, and add a teaspoon of olive oil.
While the oil is getting hot, throw in the chicken fat and skin and stir until oil exudes from the browning fat.
Throw in the sliced shallots, stir around in the pan. Count 10 seconds, and add the garlic. Stir until garlic starts to brown.
Pour in the washed rice and stir to coat the rice with oil and other ingredients. Turn off the heat.
When Stage 1 is finished, pour the chicken stock on the rice, stir to mix well and turn the heat on high.
When it starts to boil, mix in the sliced zucchini followed by any other vegetables on top, put the lid back on, boil once more and then turn the heat down to very low.
Leave the rice covered and slowly cooking for another 10-12 minutes, then turn heat off.
Steps for Stage 3
Mix soy sauce, sesame oil, wine and mirin in a large bowl. Chuck in the other ingredients and stir.
From Stage 1, extract some of the boiled seasoning from the chicken cavities, especially from between the thighs and legs, spoon on some dipping sauce and use the cooked seasoning as an extra garnish.
Finishing up and serving
Cut the chicken into pieces and plate with the rice. Garnish with sprigs of coriander or spring onions. Swish some dipping sauce over the chicken and rice, and serve.
One final trick
The last trick is to utilise the remaining stock from Stage 1. Gather the bones from the chicken after dinner and place them back in the stock along with a stick of chopped celery. Heat the pot again under very low heat and leave for a couple of hours. Strain the stock into a bottle – now you have some excellent chicken stock for use another time. You can freeze the stock or keep it chilled in the fridge for a few days.
The energy saving
As mentioned earlier, using a temperature gradient is quite an energy-efficient way to cook chicken and other foods. The relatively colder chicken is cooked by the heat transfer from the hotter water, even after it has stopped boiling.
If you’re interested, the energy consumption can be calculated as follows, assuming you needed to use 2 litres of water to do the cooking, the initial water temperature was 20°C, and it starts to boil within 20 minutes:
(2 x 4 x (100-20)) / 3412 = 0.1876kW in one hour
Hence, energy needed to boil water within 20 minutes =
0.1876 x (60/20) – 0.5627kW
This is the energy required to boil the water. Once it is boiling, the theoretical energy needed to keep it boiling for an extra 10 minutes is only:
(2 x 4 x (100-99)) / 3412 = 0.002345kW in one hour
Hence, energy needed for 10 minutes of boiling =
0.002345 x (60/10) = 0.0141kW
Therefore total energy required is 0.5627 + 0.0141 = 0.5768kW
To roast a 1.6kg chicken in an oven would require approximately 3 times the energy, assuming you have a conventional 3kW oven.
At this point, I have to apologise to Karen and Erwin, my friends from Austria, who had kindly invited me to visit their beautiful horse and animal farm in Tyrol last year.
The plan was to wander around their wonderful region and also to cook a nice dinner using one of their organically-raised farm chickens – and this was the dish I had planned.
Unfortunately, various circumstances precluded me from going, so this recipe is dedicated to them and their wonderful farm.