I never really kept my substrate too long unused... But if it is no longer usable, it will either or both: smell bad, discolored, pest infection occurred, etc.How do we know when it expired? If is too old to use it?
Yea.. unless you are using agricultural ferment starter (which is usually anaerobic), your substrate should be made aerobic. So if you don't mix it often enough while it is in process of fermentation, your substrate won't ferment properly (to feed your scarab larvae).But if I don't mix my substrate very often, will it become bad?