ANY plastic container is going to get scratches over time. They may be small but regardless they will catch stains at the least. The problem with a wide mouth container is that for aging it's a lot harder to minimize air exposure - you have to really top it off very close to the top to reduce the volume of air. I can manage getting a brush inside my carboys and if you do a good cleaning as soon as it's emptied, it's far less likely to collect anything. If you let what was in there dry....then it's scrubbing time for sure.