Only grapefruit meat can be used to make citron tea, and the method is basically the same. Tear the grapefruit meat into small flowers by hand, put it in an oil-free cooking pot, add a proper amount of rock sugar and clear water to melt the sugar first, then cook it on low heat for about an hour until it is thick, cook it and let it cool. When the temperature is 5℃ or 6℃, add honey and mix well. After cooling, put it in a sterilized glass bottle and put it in the refrigerator.