The elf and safe tea issues come when the end of the dispenser goes below the level of the beer in the glass - In other words if the pipe that the beer comes out of is dipped in the beer. If you dispense into a used glass containing some bug or another then the same bug remains on the end of the dispenser you are risking transfering an infection - Say Rotovirus or Norovirus.

I don't know if I believe it could happen but that is what a landlord friend explained to me!

The older reason is that some of the more unscupulous landlords used to pour the contents of the drip trays back into the barrels! I don't think that can be done now but I distincly remember buckets labeled 'Mild' and 'Bitter' being used to empty the drip trays into. If they were not re-cycling the contents of the drip trays why did they bother using and labeling individual buckets?

One way you can get round both of course - Only drink bottled beer poured by yourself. But just think what you could be missing!

DeG