If the venue is providing the bar then the expected takings should be taken into account in the price of the venue. An external bar should be providing you with a percentage of takings, in which case it's in your interest to work with the external bar to make sure they do well, which includes negotiating reasonable licensing hours with the council, siting the bar somewhere close to traffic, keeping it appropriately warm, etc.
There are plenty of external companies who will provide a bar. The staff may well be used to more upmarket events where they have more of a captive audience, and less used to competing with a 24 hour supermarket.
There have been several different approaches over the years (some much better than others), catalogued here: Bar history
Running your own bar
What do you need to run a bar at a British Juggling Convention (in England and Wales)?
- Team of three (at least) lead volunteers.
- Real Ale supplier
- A cash and carry with-in drivable distance
- Knowledge on licencing
- Ensure you have a licence in place for all licensable activities that will be taking place
- Work out a rough budget on the stock you require, remembering you can always have buy more, also you will have to work to the restrictions of what the BJC team can afford.
- Complete or have the relevant paperwork required by law ready
- Stock take sheets are useful for keeping track of what you sell, also you can note down anything that has affected the sales (power cuts etc)
- Ensure you have in place methods to prevent breaking of any laws.
- Recruit volunteers, ensuring that they have the relevant training
- Organise daily trips to the cash and carry, while keeping an eye on barrel levels, ordering more if needed.
- Make sure all signs are displayed correctly, and laws are not being broken.
- Write up figures to pass on to future teams for reference
- Update Wiki
Ron is happy to help and advise if you need any more information.
Also see sales figures for previous years.