Koji Chicken Tenders

Here in Japan, we love chicken thighs so much that they usually cost about 50% more than breast meat. But aside from the cost advantage, breast meat has one other thing going for it: it has a higher concentration of protein per gram than most other meats. I've been trying to get more protein into my diet, but it's been hard, because that's meant forcing myself to eat a lot of bland, dry chicken.

That's why I've been experimenting with how to make chicken breast tender and just as moist and flavorful as thighs. These koji chicken tenders (the long strips of meat tucked under each breast) are one solution I've come up with. Letting the chicken sit in a simple cure for a few days works some molecular magic on the meat, infusing it with flavor while making structural changes that help keep it tender and juicy.

Koji has enzymes called proteases that break down the muscle fibers, which makes the chicken very tender. As those proteins come apart, they turn into amino acids that we taste as umami, making white meat taste more like thigh meat. If you've cooked with koji before, you've probably used shio koji (salt koji), which is a thick, porridge-like seasoning made by mixing rice koji with salt and water and gently warming it to activate the enzymes. It's a wonderful condiment and will work here, but because some of the starch in the rice has been broken down into sugar, it's pretty sweet. By using dried koji, you get the same enzymatic benefits of shio koji, without the sweetness.

In my cure, the koji gets some help from salt and potato starch, and those two are what keep the chicken juicy. The salt dissolves some of the proteins in the muscle fibers. That loosens them up so they can hold onto more water, and they don't squeeze it out as they tighten during cooking. The potato starch gels when it gets hot, forming a protective barrier that further helps the meat fibers hold onto their juices.

Put all three together, and you get tender, flavorful chicken without a hint of stringiness. Once it's poached, you can shred it into my Lemon Pepper Chicken Salad, which also calls for poached chicken tenders. It can also be adapted into other recipes like my Chicken and Avocado Bowl or my Curry Chicken Salad. But poaching isn't the only way to cook the koji-cured chicken. It works with any relatively quick cooking method. For example, you could cut it up into bite-sized pieces and stir-fry it, or bread the tenders whole and deep-fry them.