... At the beginning of this very thread, I'm carefully caramelising Golden Syrup (dreaming up shortcuts to the process) to "recreate" historic Brewers' Invert Sugar.
Fortunately (hardly that!) an earlier bang-on-the-head lead me to doubt what I was doing and try and find evidence for it. I was in for a surprise! Even by mid-19th C. sugar refining was pretty primitive. A pound of white sugar was the reserve of the rich*. Some of whom actually owned the sugar plantations, and "owned" the slaves that toiled to keep them going. This was the environment from which came "Brewers' Invert Sugar". It was all about to change: The collapse (not "end"!) of slave labour and advancements in sugar refining beyond the primitive refining methods of old. Soon (late 19th, early 20th C.) it was to become feasible (financially) to look at "caramelisation" to provide a myriad of propriety brewing sugars.
But not before then! (The doubts in my head are obviously receding ... give me a few more months and I'll be as bigoted as the worst of my distractors).
I guess I need to assemble a (historical) summary of what I'm supporting so more are clear of what I claim? But that may be in to the New Year. Meanwhile, even Wikipedia can assemble some good guidance:
Sugar Cane Mill (Wikipedia),
Sugar refinery (Wikipedia),
Jaggery (Wikipedia), and also
Norbert Rillieux (American Chemical Society)
One thing you really need to note: The "Molasses" approach to "Brewers' Invert Sugar" if not massively different to the "caramelisation" approach, just the similarities are "incidental" and greatly more subtle with molasses. Even "Maillard reactions" will be occurring in "Molasses", but again, "incidentally", which is a good thing because "Maillard reactions" weren't described until early 20th C. (
Maillard Reactions (Wikipedia). Alkaline conditions? Look out for the use of Lime (and heat) to clarify sugar cane juice.
[EDIT: *That's a bit of a deceptive statement: "White" sugar, in the form of large "loaves" were around in the 18th C. but wouldn't have been economical enough to use in place of barley malt in beer. The Victorian period saw granular sugar appear more widely. But again, was too expensive to chuck in beer. Brewers' Invert Sugar came from various stages of that 19 C. refining process (which was increasingly carried out on home soil), avoiding some of the later expensive refining steps, not least of which would be the drying <
sic: That's not really the correct term, crytalising?> (invert syrups made more sense).
By the 20th C. advancements in (continuous) refining methods made white, highly refined, sugar the cheaper option and "brown" (less refined, "muscovado", etc.) the more expensive "exceptions". The old refining methods were no longer available for "Brewers' Invert Sugar", but it limped on as "emulations" for a while until the 1960s when most breweries had switched to using sucrose syrups and left just one manufacturer - Ragus - producing the small quantities of "emulated" Brewers' Invert Sugar that some breweries still used.]