My children have been growing herbs in an aerogarden hydroponically, and we really don't cook around here, so we thought we might turn them into gifts for the holidays. I was wondering if the risks of botulism when making cooking oils still exist if the herbs aren't grown in dirt/soil? Any ideas for what exactly we should do that would make nice gifts? We have basil, dill, purple basil, and mint. We did this for the scientific aspect of observing hydroponics in action (I'm a science teacher), but it seems a waste to not dry or preserve these herbs somehow. Any advice would be greatly appreciated.