Step 1

Begin with a third of the chili mixture in your heatproof container. In a wok or saucepot, add the cold oil. If attaching a hands-free thermometer, take care that the sensor end is sufficiently submerged for an accurate reading but not touching the metal of the cooking vessel.

Step 2

Heat oil until smoking, about 410°F/210°C on a medium heat setting*, stirring occasionally to ensure heating is even. Turn off heat and allow to cool on its own, taking care not to exceed 464°F/240°C. *If your heating element is too hot, your caiziyou will heat unevenly, producing smoke earlier on. If this happens (smoking heavily by 375°F/190°C), it's better to take the oil off the heat early than risk burning the oil. It's always possible your temperature gauge may not be perfectly accurate, so learning to judge by sight/smell is the most reliable skill for mastering your unique cooking environment!

Step 3

Once cooked oil cools to about 356°F/180°C*, pour a third of the oil into your container with the ground chilies, stirring constantly. It should bubble vigorously, but not burn. Before bubbling slows altogether, add another third of the ground chilies.*For the right fragrance at this step, the oil must be no cooler than 356°F/180°C and no hotter than 375°F/190°C.

Step 4

Once cooked oil cools to about 302°F/150°C, pour another third of the oil into the container, stirring constantly. Add the remaining third of the ground chilies and stir to incorporate.

Step 5

Once cooked oil cools to about 248°F/120°C, pour the remaining third of oil into the container, stirring constantly. Cover the container and let rest on counter for at least 24 hours before using.