In his 1857 book The Scottish Ale Brewer and Practical Maltster W. H. Roberts cautions against boiling hops for a long time and observes that “In general, it may be safely asserted that the brewers in this country boil their worts for a shorter period than those in England”. He approves:
The boiling of this wort for a longer time than one hour extracts the coarse flavour of the hop, while the fine aroma, being more evanescent flies off with the vapour…
And how did Scottish brewers hop their beer?
Four pounds of the hops were put into the copper when the wort was about 200º of heat, and boiled briskly for the space of twenty minutes; the remaining six pounds were then added, and allowed to boil thirty or forty minutes, according to circumstances.
So, in spite of knowing that the ‘fine aroma’ flies off, all of the hops were still boiled like Christmas sprouts.
What would it have needed for Scottish brewers to have the same level of hop bitterness but hang on to the fine aromas? Well, alongside reading Roberts’ book I’ve also been reading blogs on whirlpooling (at a homebrew level) hop-stands. Bear Flavored explains hop-stands in his blog and suggests achieving sufficient bitterness by viewing hops in a hop-stand as equivalent to a 10-minute boil addition. It’s a guide:
I add my whirlpool hop addition to Beer Smith as a 10 minute addition, and figure that’s close enough.
Take hop-stands, Roberts’ book and throw in period recipes from Ron Pattinson.
A hoppy, session beer with some heritage: Sounds ideal and it has plenty that Roberts would find characteristic of Scottish brewing of the time – the relatively high mash temperature leading to higher FG and because there’s a lot of unfermentable sugars, lower attenuation and lower ABV.
Should be quite a malty beer, with the bitterness offset by the sweetness implied by the high FG. What would happen if you brewed the 1851 beer but instead of boiling off the ‘fine aroma’, you kept it by extracting some of bitterness in a hop-stand?
First, to get it all from hop-standing you’d need a shit load of hops. Instead of the 2.5oz Ron specifies, using Bear Flavored’s equivalence to a 10-minute addition needs 8.6oz to achieve the same IBU.
There’s a compromise, surely. Some boiling hops for the bitterness and some late addition to keep some aroma? We’ll find out on Sunday.