I stand by everything I said in my Part I, except I think it is likely that the highwines advertised in the 1917 ad by the Montreal merchant, Moquin, probably were not distilled at 150 OP (85.6% abv) but rather were simply sold at (diluted to) that proof.
I think they were probably distilled at 94.1% abv, based on this October 17, 1879 Canadian engineering article describing a visit to Gooderham & Worts, see pg. 298. The article states that the highwines were 165 OP, which is 94.1% abv. Now, was the article wrong and it confused the proof off the stills of what became the whisky sold with the highwines proof? It is possible, but taking the record as we find it, it sounds like Canadian highwines of large distillers in this period, i.e., post-Civil War to 1917 at least, were 94% abv.
Now, that does not quite meet the neutral spirits definition, generally taken as 95% abv and over today. Distillers know that a 94% spirit can have detectable odour and taste. I know it myself as the Global Alcool I discussed in Part I is sold in two versions, 94% abv and 40% abv (presumably just proofed down). I bought the 40% and can say it is not a neutral taste. I called it “gamey” in fact…
Spirit for vodka would generally be distilled at 95% abv or higher, and anyway for Canada is treated with charcoal or other methods to refine the taste to blandness. I doubt the Global product was so treated.
94% abv grain spirit is known in the distilling business as an intermediate product.
Therefore, I now believe that what was advertised as highwines in 1917 by a number of prominent Canadian distillers, was this intermediate distillate. It would still be capable of aging in wood as it contained detectable fermentation by-products (congeners) which would alter in aging.
Also, 94% abv aged grain distillate falls within the American whiskey definition. It is 188 proof, under that is the 190 U.S. proof ceiling to call aged grain spirit whiskey. This shows again the product was not completely bland.
On the other hand, it cannot be said the 1917 highwines, under this definition, was the same as white dog spirit used to make bourbon, straight rye, single malt, or Canadian flavouring whiskey. This post will modify my earlier statements to that effect.
Nonetheless I still believe that between 1860 and 1900 not every distiller’s highwines were so high in alcohol. Especially surviving smaller distillers may have produced highwines distillate at a lower proof, in the range of bourbon or straight rye or near enough.
Needless to say, anyone interested in commenting is invited to do so.