Rinse the roses with water, then pour them into the pot, add pure water and start cooking. Bring the fire to a boil, simmer slowly, and simmer slowly for about 30 minutes.
Then cut half a lemon and squeeze some lemon juice into it at will. After squeezing the lemon, add the sugar. The next thing is to keep cooking, stirring and stirring, and don't let the roses stick to the pot. When it's thick, it's OK.