This old BBC report on porter. But not just any porter, porter the way it was poured once upon a time, when a publican had to have a pouring skill. Pouring from two different kegs meant that the publican had a great deal of power over the way the porter was experienced by the customer.
We haven’t lost the style of course, and obviously I understand that a consistent beverage is more valuable than one precisely tuned to the consumer-at least from a production standpoint. Still, I appreciate that it is a skill that has been left behind.