1. Use boiled water.

2. Wash after soaking in tea.

3. Soak in vinegar and wash.

4. Wash after soaking in beer (I tried this, and it works, but it feels wasteful. I didn't put too much at that time, so I didn't wash it thoroughly. )

In fact, this black scale is not only the residue of ingredients, but also the scale after cooking.

Casserole is a kind of cooker. Traditional casserole is a ceramic product made of raw materials that are not easy to transfer heat, such as seasonable, feldspar and clay. Fired at high temperature, it has the characteristics of air permeability, adsorption, uniform heat transfer and slow heat dissipation. The recipes that depend on casserole include casserole chicken, casserole tofu, casserole fish head and so on.

Due to the problems of manufacturing technology and raw materials, the traditional casserole is not resistant to the change of temperature difference, easy to burst and cannot be dry-burned. Aiming at this problem of traditional casserole, in recent ten years, after research and improvement, spodumene was added into raw materials to make a high-temperature resistant casserole, which can withstand hundreds of degrees of high temperature without cracking while maintaining its original advantages, greatly improving the practicality of casserole.

The traditional casserole is a kind of pottery. The invention of Tao is an epoch-making symbol in the development history of human society and the greatest invention of human development. Legend has it that Emperor Yao invented the casserole, which has a history of thousands of years.

Archaeological findings show that as early as the Neolithic Age, people began to use sand-filled pottery (similar to the current casserole). Sand-mixed pottery is a common kind of pottery in Neolithic Age, mainly red pottery and gray pottery. After the improvement of past dynasties, sand pottery has evolved into the casserole we use now.