It would be selling beer. If you didn't have a licence it would be illegalI'm not a legal professional, or Bar room barrister, one thing I have learnt in life is don't prod the tax and excise man. Find a loophole they won't thank you, they will close it immediately and you will be forever on their radar.
What if you charged the students for the beer you provide, itemise it in their costs of enrollment, if its only small amounts say a 350 mm stubby between three students not going to be outlandish. I can't see how that could be illegal.