According to the personal database, maltol refers to ethyl maltol, which is used as a flavor improver and flavoring agent. The dosage is very small, but the effect is very obvious. Generally, the dosage is about 0. 1 to 0.5‰, and sometimes only a few PPM is effective. However, ethyl maltol is easy to form a complex with iron, and will gradually change from white to red after contact with iron. Therefore, the use of iron containers should be avoided when storing, and the solution should not be in contact with iron for a long time. It is advisable to store it in glass or plastic containers. So you can't use an iron pan because there is a reaction.