Why It Works
- Curing duck legs with funky shio koji imparts savory depth to the meat with a hint of sweetness, while also tenderizing it. Because of the salinity of the marinade, there is no need to season the duck with additional salt.
- The sugars in the shio koji also help the duck skin achieve a burnished, deep golden brown color when crisped up for serving.
- A gentle and slow cook in a low oven yields tender and silky duck confit.
- Fully submerging legs in duck fat allows them to be stored for a long time after cooking, while also imparting the fat with extra flavor for subsequent cooking projects.
For this spin on French duck confit, we use shio koji in place of the traditional salt and spice cure, slathering it on duck legs with black peppercorns and star anise. The salt and enzymes in the shio koji quickly go to work, deeply seasoning the meat in just 12 hours. The koji cure is then rinsed off, the duck legs are submerged in rendered fat, and they're cooked low and slow in the oven until tender.
This duck confit is intensely savory, with a background note of sweetness from the natural sugars from the koji kin, which also helps produce deep golden brown skin when you eventually crisp it for serving. If you've been curious about the transformative powers of shio koji, this is a great recipe to start with.
The Day Before Cooking Confit: Combine duck legs, shio koji, peppercorns, and star anise in a 1-gallon zipper-lock bag. Seal bag, pressing out as much air as possible. Massage bag until duck legs are evenly coated on all sides with shio koji. Lay bag flat on a rimmed baking sheet and refrigerate, for at least 12 hours and up to 24 hours. Do not cure legs longer than 24 hours, as they will over-cure, resulting in salty and dry confit.
When Ready to Cook: Adjust oven rack to middle position and preheat oven to 225°F (105°C). Melt duck fat, either in a 3-quart saucier over low heat, or in a microwave-safe bowl in the microwave. Remove duck legs from cure, wiping away as much of the cure mixture as possible before rinsing legs gently under cold water to remove all seasonings; discard cure. Pat duck legs dry with paper towels, then arrange in single layer in saucier with duck fat (if using), making sure they are completely submerged in fat. Alternatively, arrange duck legs snugly in a small baking dish and cover with melted duck fat, making sure legs are fully submerged in fat.
Cover saucier or baking dish with lid or aluminum foil, and transfer to oven. Cook until duck is completely tender and meat shows almost no resistance when pierced with a paring knife, and skin has begun to pull away from bottom of the drumstick, 3 1/2 to 4 hours.
Remove from oven and cool duck to room temperature in its cooking vessel, removing lid but keeping it submerged in fat. Once cool, cover container tightly and transfer to refrigerator, where confit can be stored for up to 1 month.
This recipe will work with all breeds of duck, but was developed using Pekin (also known as Long Island), and Alina ducks.
We do not recommend using store-bought prepared shio koji for any recipe, as store-bought versions vary wildly in quality. They are often too sweet and are treated with alcohol to extend shelf life. Making your own shio koji is worth the effort.
The amount of duck fat needed for this recipe is dependent on the size of your cooking vessel. You need enough rendered duck fat to fully cover the legs and keep them submerged throughout cooking. You can render duck fat yourself from breaking down whole ducks, and also purchase containers of rendered duck fat at well-stocked supermarkets or online.
This recipe can easily be scaled up or down for any number of duck legs you want to make; just note that the ratio of rendered fat to duck may change dramatically as the size and shape of the cooking vessel does.
Make-Ahead and Storage
Duck confit can be refrigerated in an airtight opaque container, with legs completely submerged in fat, for up to 1 month. The duck fat from the confit can be re-used at least 2 more times for subsequent batches of confit; after the third use, taste it for salinity as it will eventually become too salty.