This song was collected by Bob Copper in 1954 from George Attrill of Fittleworth in Sussex.
If a song is all the better for the singer knowing what he is singing about – and I believe this to be true whether the subject of the song be fishing, ploughing, mining or loving – then there could never have been a man better qualified than George to sing this song. Every lunchtime of his life would find him in the Swan at Fittleworth where ten or twelve pints of mild would slip smoothly and rapidly down his gullet before lunch could be considered complete. And he would round this off with another five or six leisurely pints in the evening.
Bob Copper, Songs and Southern Breezes (Heinemann, 1973) p81
I have never heard a recording of George Attrill singing this, so I’m not sure how far my tune departs from what he sang. Certainly the tune is transcribed differently in Songs and Southern Breezes and Peter Kennedy’s Folk Songs of Britain and Ireland which is, I think, where I first encountered it. From Bob Copper’s book it seems that when George sang it, all four lines of the verse used pretty much the same tune. Whereas in Kennedy’s book the third line is quite different (and that’s how I sing it). There’s also a divergence in the chorus. Peter Kennedy has the ascending line on “Old and young thy praise have sung” starting on the tonic. I start the run one note higher, and – having looked again at Songs and Southern Breezes – that’s how it’s given there. I’ve heard it sung both ways. Right or wrong, I think my tune has a bit more interest to it – but it does make it a song worth avoiding in folk clubs and sessions, unless you’re a fan of dissonance.
There’s a Mudcat thread on this song, from where I learn that the song was originally composed – with a significantly different tune – by Joseph Bryan Geoghegan in around 1860.

Joseph Bryan Geoghegan, 1816-1889. Image found via a Mudcat discussion on the composer of this song.
John Barleycorn’s a Hero Bold