Divided into specific cases. Damp white sugar just absorbed water, the nutrients have not been destroyed, if the moisture is not heavy, and time is not long, properly handled can be eaten. But if the time is long, white sugar is susceptible to bacterial contamination, the color changes, indicating that it has deteriorated, it is best not to eat.

Sugar caking solution:

1, prepare a clean and moist cloth, slightly wrung out and then covered in the mouth of the bottle of sugar, after a period of time, the sugar will slowly become soft as it absorbs water and moisture.

2, will wash the apple, cut a small slice with a knife, into the sugar jar, cover the lid, 3 hours later, a small amount of water in the apple, enough to make the dry lumps of white sugar become loose. If you have a lot of sugar in the jar, leave the apple slices overnight, and the next morning the lumps will be loosened again. If you're in a hurry, you can also put in a few more apple slices, cover them, and they'll be ready in about 2 hours. In addition to apple slices, carrot slices, celery pieces, can solve the problem of white sugar lumps.

3, put the white sugar in a plate and put it in the microwave oven. The shortest ten seconds can be resolved, the longest not more than 5 minutes, in the process, be sure to pay attention to the changes in the plate of sugar, do not overheat and become "sugar water".