Shio koji is a condiment made from salt (shio), water and rice malted with koji kin, a type of Japanese mould. The mould breaks down proteins to create glutamic acid and consequently umami flavours, a process that also tenderizes meat and fish. The same mould also converts starches into glucose, drawing out the sweetness from ingredients and helping foods to brown more easily. Because of this catalytic process, shio koji brings out a much wider range of flavours than plain salt can. For best results, marinate the chicken for the entire 48 hours, cover it with foil and keep an eye on it to avoid over-browning during cooking.
- Yield: 4 Servings
- (6¼ oz) (175 g) Shio Koji, blended until completely smooth
- 2 garlic cloves, crushed
- 1 tsp sansho pepper or another dry spice or herb of your choice
- 1 whole, good-quality cornfed chicken (approximately 1.75 kg/4 lb)
- If making your own Shio Koji, start making it at least 7 days before attempting this recipe.
- Crush the garlic cloves and mix well with the sansho pepper and the smooth Shio Koji to make a paste.
- Untie any strings attached to the chicken to allow the heat to circulate more evenly during cooking. Rub the entire chicken with the garlic and shio koji paste. Lift the skin at the top of the neck and rub it onto the chicken breast and under the skin, working as far down as you can. Place the chicken in a roasting tin (pan), breast side up, loosely covered with foil, then transfer to the fridge and let it marinate for 48 hours.
- Preheat the oven to 180°C/350°F/gas mark 4. Take the chicken out of the fridge 30 minutes before cooking to bring it to room temperature. Transfer to the preheated oven and roast for 1 hour and 20 minutes covered with foil (40 minutes per kilo plus 15 minutes). Turn the chicken occasionally to cook it evenly and keep an eye on it as koji-marinated meats tend to brown very quickly. If this is the case, lower the heat and roast the chicken for a little longer until cooked. Remove the foil 10-15 minutes before taking the chicken out of the oven for a crispy and golden skin.
- Pierce the thickest part of the thigh with a skewer and let the juices run out. If they are clear, then it is cooked, but if they still look pink, return to the oven for a further 10 minutes, then test again. If you have a meat thermometer, push the probe into the thickest part of the thigh. The temperature should be 75°C 165°F for cooked chicken.
- Lift the chicken and drain its juices from the cavity into the roasting tin (pan). Transfer the chicken to a carving board, cover it with foil to keep it warm and let it rest for 10 minutes. Carve the chicken and serve immediately.