I think I know now what the real musty ale was, although it is a series of educated inferences. I think it was what contemporary brewing writers called lively ale, sometimes too cream ale, but where the lively character was stimulated by adding partially-fermented beer to finished beer rather than, say, injecting it with carbon dioxide in the fashion of a soda siphon or soft drinks.
(Beer completed fermented out often is flat from the carbonation escaping during conditioning, or it was in the period of open fermenters and wood vessel storage).
This procedure was well-known in lager-brewing, as krausening, but Americans practiced something similar in ale-brewing as well, especially before carbon dioxide injection was developed.
I’ve written on cream ale and explained that some brewers used cream of tartar or similar chemicals to ensure good carbonation (condition) and retard acidity. This practice was current in the last part of the 1800s. It withered on the eve of WW I due to better methods to control stability and the gaze of emerging food regulators.
In this 1897 article from the Journal of the Institute of Brewing a simple explanation is given of the various types of ale prevalent in America. There was lively ale (very carbonated), also called present-use; still ale (like well-kept cask beer in England); and stock (old) ale, long-stored as in England. Stock ales generally were on the flat side, at least the draft.
The writer does not mention musty ale, nor do brewing scientists Wahl & Henius who wrote in the same period exhaustively on American beer. This suggests “musty” was a trade designation, an advertising term not a brewers’ technical one.
Musty ale may well have been krausened ale. The addition of freshly fermenting, or fermented, beer to spark a new fermentation and create a high volume of gas might have suggested use of the term musty in its older sense. I don’t think German lagering stimulated the procedure in ale-brewing, the Cincinnati connection notwithstanding, since musty ale was known there in the 1850s and lager was just getting started. Also, it seems musty ale was known in Vermont in the 1840s where there was no lager.
Irish brewers in the 1800s added partially-fermented wort to finished beer to impart the creamy head (today aroused by nitrogen), which is a similar idea. See Frank Faulkner’s comments in the 1880s, here, on adding such “heading” to porter before the casks went out to the trade. Maybe the American musty practice was an adaptation of this idea, given too the prevalence of newly-arrived Irish in New England in the mid-1800s – especially Boston.
This is from Tim Daly’s Bartenders’ Encyclopedia, 1903. It was published in Massachusetts – spiritual heartland of musty ale.
The odd-seeming mix of ale and lager was clearly a rough way to emulate the musty of the breweries, a bartenders’ trick. Draft lager would have been unpasteurized, and the addition of a fizzy, yeasty lager to well-matured ale probably emulated the musty taste. Even if bottled lager (pasteurized) was used, its high carbonation and fresh character would have made a still ale much livelier.
It seems clear musty ale was not like other ale. In this 1915 article which appeared in numerous papers in that year, Harvard students are described visiting a tavern and asking for “ale”. The bartender tells them he only has musty ale, which implies it is a special form of ale. They drink it, like it, and return later with more friends, whence the tavern requests its supplier to send it ale “made musty”. This suggests a special technique of making musty ale, which I suggest was adding partially-fermented wort or new yeasty beer to flat production beer – or stock ale in some cases – to make a fresh lively mix.
It is true some musty ale was advertised as old. This may have been truly old ale by confusion with the meaning of musty in its brewing sense, or, perhaps a combination of heading or new fresh beer with still stock beer. British breweries would often mix old and new beer to get a balanced palate and good carbonation, some porter was produced that way.
Musty ale probably is entangled with one or more of these older traditions, but has the distinction of the unusual name, an American feature yet with English antecedents even there.
Finally, it’s possible some brewers added new lager to ale to get the musty character, and there have been recurrent stories in American brewing history of such practice.
As coda, let’s imagine a scene at the Python Bar, Cambridge, MA, c. 1900:
“May I have the Musty Ale, I feel like an ale today with that taste of old overcoat, old cellar you might say”.
“We don’t have any, sorry“.
“But there is the sign, ‘Musty Ale’!”
“This will taste like what you want, it’s Burton Ale aged nine years“.
“Don’t want that, too dear”.
“Well, we have some Bass ale from a fire sale, so reduced price, want that?”
“I want your Musty Ale, there, you’ve just poured one for that Harvard boy over there!”.
“Our ale isn’t musty sir“.
“Your sign says Musty Ale!!”.
“We haven’t any ale of that description, I’m afraid, other than what you decline to buy“.
“What kind of place is this, do you toy with all new customers in this fashion? I won’t be trifled with, where’s the constable!”.
“Sir, it is I who will call the constable unless you calm yourself, perhaps you are a stranger to this section, and misapprehend what Musty Ale is…“.
[Customer storms out, thinking, “From this moment I shall simply drink lager at the German saloons. Good riddance to this ‘old Englyyshe’ ale and its weird practices!”].