I've often heard that Maris Otter provides some of these flavors over regular US 2-row, but maybe to my untrained tongue, this character is perhaps most striking in a simple pale ale or bitter and that it might be lost in a brown, porter or stout. If I start adding in amber, victory, special roast, and even chocolate, I assume the difference between the two base malts are greatly narrowed?
If not, what benefit is received from using Maris Otter with these specialty grains?
You're absolutely correct. Pale malts - regardless of variety - are so similar that only in the beers brewed almost entirely with pale malts can you detect any difference. That's why SMaSH beers are so educative: They reduce variables to the point that distinct differences between ingredients are readily apparent.
Here's an interesting thought experiment: Think of pale malt as meat - say, turkey. A wild turkey killed in the deep woods is going to taste different than a wild turkey killed near soy or corn fields (different feed) is going to taste different than a farm-raised domestic bird, provided you cook them all in the same way: Plain. Now, if you start putting things like Caribbean jerk seasoning or BBQ sauce or mango chutney or even extra virgin olive oil on the meat, or change the manner in which it's cooked, the flavor changes entirely.
Indeed, depending on the strength of flavor in the accompaniment and/or preparation technique, any flavor imparted by the turkey itself can be completely lost in the flavors imparted by the accompaniment/technique. Some differences are more subtle, like between oven roasting and pan-seared. Others are more obvious, like oven-roasted versus slow-simmered with Vindaloo sauce.
That's the parallel with pale malts. Differences in the malt itself - UK 2-row (Maris Otter, etc.) vs. US 2-row vs. EU Pilsner - are like differences in the meat itself - wild vs. farm-raised. Other differences come from technique; the same malt can taste completely different based on what technique you use in the brewhouse. Differences in prep for the meat - pan-seared vs. oven-roasted vs. boiled - are like differences in brewing techniques - single-infusion vs. decoction mash, one hour boil vs. 5-6 hour boil to concentrate wort (a la Scotch Ale). Other differences come from other ingredients cooked with the main ingredient - with turkey, plain vs. jerk vs. vindaloo; with malt, plain vs. Crystal vs. Chocolate vs. ??? else in the grist.
Different base malts do tend to marry better with different style grists, just like different meats tend to marry better with different dishes. It's difficult to make something resembling blackened redfish with, say, shark; shark is a more strongly-flavored fish, and that impacts the dish. Same with malt. It's difficult to brew a Tripel with Maris Otter that's true to style; you're better off using Pils malt.
Back on topic, Nut Brown Ales are a good candidate for Maris Otter and other more highly-flavored pale malts, as the crackery, biscuity characteristics of the pale malt meld well with the flavors you intend to extract from the specialty malts in a Nut Brown grist. That said, you can brew an outstanding Nut Brown using all domestic ingredients; I've done it. It's going to be slightly different, but it'll still be excellent.
This Ingredient Flavor Exercise brought to you by the letters "OMGWTFBBQ!!!1!!"
Bob
