Certainly the Wild Turkey products have a rich quality especially at older ages that surely owes something to their historically low entry proof. I believe their rye, if it would be issued at 8-12 years of age, would show the kind of caraway-like richness that has been noted of some traditional rye, in fact.
I just found out that Joseph Fleischman's book is on full view at Google Books:http://books.google.com/books?id=ABoZAA ... q=&f=false
The full read is most worthwhile, for its inherent interest and e.g., statements such as his practice to age his blends (marry them) in barrels at the top of the warehouse at least 3 months. Or, his comment that bourbon 10-15 years old is too old except for blending purposes. (Wha...? Tell that to some of the mavens in these parts).
Look at his recipes for "tea extract" and "raisin extract" (pg. 16-17). His best rye whiskey blend, no. 17 on page 31, is 3 straight ryes: Guckenheimer, Hainesville, Monticello, all well-known historical names, plus tea extract. Note how heavy the raisin extract and tea extract are on raisins and currants, respectively. So if the Maryland blends had a raisiny taste, this would seem why. When I made my own version of no. 17 blend, I macerated raisins in tea liqueur. I didn't get a raisiny quality in the blend because, first, I don't think my flavouring was as concentrated as Fleischman's. Second, I used only the percentage he advises (scaled down of course), and it is very small, he uses only a half gallon flavouring to 45 gallons of pure whiskeys for his no. 17. One can envision that in the cheaper blends, even that same percentage of flavouring would stand out more, though, since it is being displayed by the GNS content. No. 17 used no GNS though, and nor did Melrose's blend of straight rye whiskeys according to the company history I mentioned earlier.
However, one can easily envision that regardless of the relative proportion of straight whiskeys and GNS used by the different rectifiers, some simply upped the amount of flavouring in their products, probably to boost profits. I recall Mike Veach reproducing rectifiers' recipes on BE some years ago showing such higher percentages, e.g., from a liquor broker in San Francisco, later 1800's. So Chuck, the "raisin" connection seems a longstanding one. In Byrn's book, he advises to add a raisin distillate to new malt whiskey (his malt whiskey is permitted alternately to use corn) to give it a "defining flavor". Chuck, didn't you once write that a raisin wine used in blending was being made at Michter's in the 1970's or early 80's? Or was it a prune wine? Anyway, it was something of this general type. Our forefathers liked the taste of raisins - currants are similar, prunes to a degree - and used it to enhance the taste of cereal grain whiskey.
I added some Southern Comfort, which is similar to some of Fleishman's fruit blends, in the percentage his no. 9 bourbon blend calls for, which again is just 1.5% or so, to a mixture of bourbons and some Canadian whiskies. Just as the Melrose book said, you could not tell the addition had been made, but it did marry the whiskeys very well. But again I surmise, and we know from some evidence, that many blenders went a little heavy in the fruit department. In fact, if the whiskeys used to blend were young, I think more flavouring was called for, as seems the approach with rock 'n rye liqueur for example. There, the fruit becomes fairly defining. But the artist in blending can mix his primary elements in his alembic as his materials and judgment call for: the final result will be what he designed and it will please palates who like that taste. Fleischman gives one approach (or variations on a theme) but allows that the formulas can be extended almost indefinitely. He does claim though to render the blends that were common in the market in his day.
Finally, a mingling of straight whiskeys can be confected without any marrying or flavouring agent: the Scots have been doing that a long time for their vatted malts and in a sense the minglers do it too at American distilleries since even bourbon of one make is often batched from stocks of different ages and/or warehouses and/or locations therein (and sometimes even from different plants). We are on a continuum here...