Remove the head and core of Sydney.
Cut Sydney into small pieces and add them to the stew.
Add 9% full water.
Cover the pot, put it into the rice cooker, add a proper amount of water into the rice cooker, and simmer on low heat 1 hour.
Add some boiling water on the way (cold water is not allowed, so as not to break the stew when it gets cold).
Finally, add rock sugar and stew for another 20 minutes.
You can stew it and drink it, or you can naturally cool it and put it in the refrigerator, which will be cooler.
Matters needing attention
Don't peel Sydney, because pear skin is a good medicine for moistening throat, but in the early stage, you should wipe the surface with salt, rinse with running water and remove the core, otherwise it will have bitter taste and affect the quality of sugar water.
The amount of rock sugar can be added according to your own preferences.
The water content of the rice cooker should be half that of the stew pot, and some boiling water should be added halfway.