The pint glass is a perfect fit for 500ml of ale. If you tip it into the glass with a modicum of care, you end up with the head not quite reaching the top. (Of

The pint glass is a perfect fit for 500ml of ale. If you tip it into the glass with a modicum of care, you end up with the head not quite reaching the top. (Of course, had we switched to 500ml glasses, leaving ale in 568ml bottles, we'd be stuffed. A point to bear in mind if contemplating a piecemeal transition.)