I think the song you are thinking of was by Ted Edwards. I can only remember a few of the words but here goes

A long time ago in the land of the Tyne
The natives were all getting tired of wine
So they dredged up some muck from the Tyne river bed
Added gallons of nitro and then proudly said

Chorus
"Call it Newcastle Brown, Newcastle Brown,
It's the finest of beer that you'll find in this town
I'd walk many a mile to sit here in style
And drink of that Newcastle Brown."

Unfortunately I can't remember any other verses. If you find anyone who has the book that Ted published in the early seventies, the words are in there. My copy went west years ago but if you know any folkies from the Eccles area they might just have one lurking around.