Red bean paste with old rock sugar will still be bitter. Why? Probably because you chose the wrong red beans. After you put the old rock sugar in, you must stir it slowly with a spoon. In that case, the overall taste will be better.
I suggest you add some dates to the bean paste. First of all, you must cook red beans and put them into a wall-breaking machine to make red bean paste, then air-dry them and put them into a film bag for freezing. After cold storage, you can take it out, then put it in a pot, add appropriate amount of white sugar and old brown sugar, and add appropriate amount of water to stir.
Gradually, we have been using slow fire, and we can add some cooking oil when it turns to a similar situation. The specific goal is to better fry unnecessary water. In the whole process here, everyone must add a lot of old brown sugar, white sugar and old rock sugar. In that case, the whole taste will be better and better. If everyone is worried about being burned, I suggest that you'd better add the right amount of water.
The bitter situation is probably because everyone's red beans are broken. Because red beans are not red grapes, it is not easy to make red bean paste. If there is bitterness, there is probably another reason, that is, because we were fired under speculative circumstances, so there will be bitterness.
I also suggest that you don't eat something with a developing trend, otherwise it will do some harm to the human body. Moreover, after we make the red bean paste, we can also select it and put it into a thin film bag, because in that case, the taste will be better and better. In the case of fried bean paste, we must quarrel gradually. In the process of frying, everyone can also use a shovel to press it.