Roast chicken is a favourite amongst many. In Singapore, the roast chicken sold by chicken rice vendors are aplenty, and often, the standard of the roast chicken offered is excellent. However, there is a place for very special roast chickens. Like those offered by Cafe de Hong Kong, for instance. Crispy skin, succulent meat.
Roasting chickens at home is altogether another affair...and often a hit and miss. The traditional method is to season, and oven roast at 230C for about 45mins or untill golden brown. While this may work, it goes against the physics and chemistry of cooking meat, and being a physicist by training, I was intrigued to do it the right way.
Searching web resources and remembering a BBC show I saw a while ago..."In Search of Perfection"...sounds like a management guru trying to make some bucks, but no...the program featured Heston Blumenthal, the chef and owner of The Fat Duck...the iconic 3 Michelin starred restaurant in England...now also arguably the reigning best restaurant in the world...after playing second fiddle to El Bulli for many years, as the Spanish restaurant is taking a sabbatical.
Heston uses science to cook his food...and this really intrigued me. He mentioned Harold McGee, who explained that in order to maintain maximum juiciness in meat, it has to be cooked at lower temperatures. This is because heat causes the protein molecules to deform, in the process squeezing out the moisture in the meat, making it dry and hard. He proposed that cooking at the optimum temperature - 55C to 60C, one gets to preserve the maximum moisture in the meat, making it very juicy and moist. The downside of this type of low temperature cooking is that it takes a long time to cook, and because the moisture is not squeezed out of the meat, there is no dripping, and hence no gravy.
But the cooking method preserves all the meat's juices, and all the flavour.
Start with a whole chicken. Cut into 8 parts - breast, wings, back, legs.
The first step of this recipe is brining. This is an important process as even with low temperature cooking, moisture is lost from the meat. In a regular oven operating at 230C, as much as 20% to 30% of the moisture is lost. At 60C, perhaps 10% to 15% is lost. Brining allows the meat to gain about 10% in water content before the roasting. Thus the final roast is only suffers a loss of moisture of only about 0% to 5%. Much more juices and flavour remain than in regular roasting. Brining also has a secondary effect...the salt solution dissolves some of the support structure of the muscle fibres so they cannot coagulate and makes the meat hard.
Brining is quite simple. A salt solution is made by measuring the amount of water needed to just cover the chicken pieces. Measure 10% of this water's weight in salt, and dissolve this in the same amount of water. Allow the brine to cool. Submerge the chicken in the brine solution. Aromatics like cloves, bay leaves, fennel seeds, may be added to the brine. Cover, and put in the fridge for 6 hours.
After 6 hours, remove from fridge. Pour out the brine and aromatics solution, and replace with cold tap water. Allow to stand for 1 hour, changing the water with fresh cold water every 15 minutes. This helps get rid of the salt, and reduces the saltiness in the meat.
Take care when handling the brined chicken. As the brine has partially dissolved some of the muscle, the chicken is very fragile and may break with rough handling.
Prepare a pot of boiling water. Make sure it is boiling vigrously. And a pot of iced water. Remove the chicken from the cold water, and immerse completely in the boiling water. It is important to ensure that the chicken piece is entirely immersed, and the water is boiling. Be careful when doing this as the water is very hot. Allow 30 seconds for the chicken to be pasteurised by the boiling water, and not more. We want to kill the germs and bacteria on the surface of the chicken, not cook it. After 30s, immediately dunk the chicken into the ice water. When the chicken is cool, and the water boiling again, repeat. Dry the chicken with cheesecloth or similar.
The next stage is to dry the chicken, skin side up, in the fridge. Leave uncovered in the fridge, for 12 hours. This will ensure the skin is very dry, and will allow it to crisp up, when cooked. This same technique is used for Peking Duck, and roast chicken/ducks in a commercial kitchen. You can see this in some kitchens, where they hang the birds out to dry.
Remove from fridge, the chicken should be very dry. Warm up your oven to 60C. This is critical, because cooking at higher temperature will squeeze the moisture we are trying to keep inside the meat out, making it dry. Because the cooking temperature is so low, we need to ensure the core temperature of the meat reaches 60C for at least 15 mins to ensure all pathogens are killed and the meat safe to eat. To do this, is important to use a meat thermometer.
When the core temperature of the thickest piece of chicken reaches 60C and stays there for about 15 mins, the chicken is cooked. While waiting for this to happen, make sure the oven temperature is not more than 60C itself. Use another thermometer to ensure that. Many non-commercial ovens cannot achieve this low roasting temperature, so leave the oven door open slightly and monitor the thermometer.
At this stage the meat looks pale and yellow, but it is fully cooked. And the skin is actually quite crisp. But it doesn't look appetizing.
Heat up a heavy iron pan with some peanut oil. You can also use a little butter for added nuttiness if you like, but nut oil is better as it can reach higher temperatures. Make sure the oil is very hot...you can judge this when the oil starts to smoke. Carefully slide the chicken into the hot oil. Don't fuss the chicken...allow no more than 2 minutes a side...I find 1 minute sufficient. When the skin is cooked, it will release itself from the pan, and be crisped to a beautiful golden brown. Turn the chicken over and do the same to the other side. The aim here is to brown the chicken...cause Maillard, not to cook the chicken. So it is important to brown the chicken as fast as possible, so as to avoid further cooking the chicken...remember the high temperature of the pan will squeeze out the moisure we fought so hard to retian with the brining and the slow cooking.
Serve. Alternatively, as suggested by Heston Blumenthal, melt some butter and use that to fry the chicken bits - like the tips of the wings, neck, bishop's nose. And use a baster to suck up the chicken infused clarified butter, and inject into the chicken. This will infuse the chicken with more chicken flavour.
The chicken will be super tender, super moist meat. You may find the meat near the bones pink. But don't be alarmed. It is cooked and safe to eat. And because of the fast pan searing, the skin will be very crispy.