I train all my staff in all areas of our daily cafe life. Of course it takes time to assimilate. And some have a greater aptitude than others. I also train them not to guess at an answer, but to ask someone else before answering a question if they're not sure. Nobody can know all there is to know about every aspect of anything. What's important is learning when and how to find information, not attempt to be an encyclopedia, which for all but maybe a very select few is virtually impossible.
You know, I think that info is available to all of our employees here in Mississippi, but let's face it... as much as I care, and trust me, I do, seems like the south is a mecca for uninformed coffee customer migration. No customer has EVER asked me or any of my fellow baristas that question. I believe we are pulling shots at 202 degrees. I'll double check tomorrow. I would LOVE to have customers coming in asking tough questions. Something that would make all of our baristas dig a little. I have managed 4 different shops, but at my new location I am a barista, and I hate it that so many baristas here in the south get the title just for pushing a cup of coffee over a counter. Everyone should be trained on all aspects of the coffee they are serving.