"There have been no small contests as to the part which hops play in the manufacture of beer. Some have been bold enough to contend that they possess no preservative qualities whatever, and only contribute flavour. The balance of opinion, however, is clearly on the side of hops being preservative; and whichever view be right, it is quite certain that their pleasant flavour has done more than anything else to make the beverage of which they are an ingredient so universally popular.
Hops, as is well known, are largely grown in the south-east of England, and even so far north as Worcestershire. Our climate, however, is just too cold and damp to produce the finest qualities ; and although the best Farnham Town hops are equal to any foreign growth, they are exceptionally good for England, while Austria and Bavaria can supply large quantities not inferior to our most superior examples. We understand that Herr Dreher and the great Bohemian and Bavarian brewers keep their hops unpressed, loose in bins like corn, not tightly packed in bags or pockets, as we do, and that the fact of the hops never having been pressed or artificially dried adds greatly to the delicacy of their aroma. Be this as it may, the repeal of the excise on hops, bringing with it that of the Customs' duty on foreign hops, has largely increased the facilities for using hops from America, from Belgium, from Alsace, and from other parts of Germany, while the acreage of English hops does not appear to be on the decline. The pleasant aromatic bitter of the hop is chiefly contained in a glutinous powder found between the scales of which the hopblossom is composed. Hops are ' dioecious' plants, having the male and female blossoms on different plants. The hop of commerce is the female blossom, slightly dried in a kiln or hop-oast, and packed in bags or pockets for sale."
"The Quarterly review, Volume 131" 1870, pages 136-136
Did you spot that? Another Anton Dreher mention. The stuff about the different way of storing hops is new to me. I'd assumed they were always pressed to reduce as much as possible contact between the hops and air.
It's right that this is the period when foreign hops began to be used more. They crop up more and more in the brewing record. mostly described as Bavarian, American or Alsace.