While it's most popular in
Scotland, this rather disgusting drink is still fairly popular in
England (at least in the North) to the extent that there are several rip-off cheap label versions available, usually sold as '
Iron Bru'
There is also a toffee version of this drink, made by McCowan's, the makers of Highland Toffee, IIRC. It tastes nothing like the drink, but still manages to be equally unpalatable.
Apparently the two people who know the secret recipe for this gunk get together once a week and mix up a vat of concentrate which is used for its production in every plant. Rumour has it (surprisingly unmentioned by everyone else in this node) that the main ingredient other than sugar and water is seaweed.