How important were hop varieties to pre-20th century brewers?

I was flattered to be asked to take part in one of the virtual symposiums (symposia?) at the Chicago Brewseum’s Beer History Summit last week, the panel I was on discussing “A History of Hops in the Western World”, and my particular brief being to talk about “An examination of hop production and use in… Read More How important were hop varieties to pre-20th century brewers?