Tim H in the comments to the last post had asked about dry-hopping of stout and porter, pointing to evidence some beers were so treated. Dry-hopping means, adding a handful or more “dry” (unboiled) hops to the beer when barrelled or sometimes stored for a time in a vat or tank before barreling.
If you look at p. 400, here, of A Textbook of the Science Of Brewing (1891) by Edward Moritz and George Morris, you will see the statement that dry-hopping was not generally done for stout and mild ale.
The reasons can be inferred from Moritz’ explanations of the advantages: primarily for bouquet and taste in pale ale, and also to help stimulate an after-fermentation for long-stored beers. Export stouts fell into the latter case, so that Brettanomyces yeast would consume the non-fermentable (by normal brewers yeast) dextrins and complex sugars in the beer.
You don’t want that for mild ale, where a fresh, sweet quality is sought and hops play a moderated role in comparison to pale ale, or for porter served for quick draft as they used to say. Quick draft means no prolonged after-fermentation. I think too with stout you have the aroma of the malt, especially the roasted malt, as a signature, and it was felt a flowery hop note didn’t complement that (as for pale ale), but would clash with it.
Certainly porters handed down to us before the craft era in my experience did not have a strong hop smell and taste: Sinebrychoff Porter, Carnegie Stout, Anchor Porter, Molson Porter, the surviving U.S. regional porters, Guinness, Murphy, Beamish, Sheaf Stout, Lion Stout, the East European porters: none of them had a pungent hop smell one would associate with dry-hopping.
To me this confirms what Moritz and Morris wrote. Moritz in particular was a highly regarded brewing scientist of the late Victorian period.
To my best recollection, Frank Faulkner stated the same thing or one can infer it from his directions on how to brew stout. I recall as well similar statements in issues of the Journal of the Institute of Brewing. Wahl & Henius in the U.S. too, IIRC.
Did some breweries diverge anyway from this standard? Yes, as Moritz himself noted. But it was not typical, and I’d think as a brewing expert and advisor he would know. 20th century practice is less significant here imo as gravities had fallen and dry-hopping will encourage stability, as Moritz notes too, but nonetheless the pre-craft porters I can think of hewed to Moritz’ statement.