Seams like she's not a very good business woman. A northern pint with 10mm of head is about 40ml short of 568ml. You'd get an extra 5 pints per firkin which in London money is about £20.
8mm is about right up here I reckon. I will linger at the bar until the head has separated properly.
8mm is about right up here I reckon. I will linger at the bar until the head has separated properly.