BeerBorg

is there any real significance in the final outcome in a dubbel made with Dingmans pale malt vs rahr 2 row as the base to justify the price difference?

I would think either would be good... With the Dingemans being a little darker which might bring a tad more character in the flavor profile.

Of course, it you are also using Special B and Candi Syrup that point might be moot.

Also, here's a cool site, but it doesn't list Rahr malt:

Malt Descriptions

I cobbled the Dingemans description below from two sites and the Rahr description is from Morebeer's site:

Dingemans Pale Ale Malt is a fully modified pale ale malt from quality two row barley.  Great all-purpose malt and will eaily convert with a single temperature mash. This malt is interchangeable with British pale ale malt.

Lovibond 2.7-3.8


Rahr - A great base malt from the Northwest, this 2-row can best be described as a cross between American and English 2-row. A nice, floral aroma with a sweet taste make Rahr 2-row a fast growing malt of choice for many commercial brewers.

Lovibond 1.9

I don't know the specific differences between those two, but it brought to mind my visit to my LHBS after work yesterday. I'm going to do a Saison; recipe calls for German Pilsner malt. I brewed the same recipe June 2013 using a pale malt. I decided to check out the difference between the different Pilsner malts on hand, so I viewed & tasted a small bit of each choice there.
-Weyerman Pilsner
-Briess Pilsner
-Gambrinus Pilsner
I chose the Canadian Gambrinus because the kernels looked more plump on average and tasted more 'fresh' than either the German or US malts. All three have a slightly different flavor. If you have an opportunity to check the differences side by side, I would highly recommend it. In my opinion, sometimes the cheaper option tastes better, time spent in a bag in a warehouse, or in a container, can make a difference.

You would notice the difference more in a pale beer. IE if you were using just Belgian Pale malt in say something like a Blonde, you might find that to achieve the same result with an America/Canadian lightly kilned 2-row you would need to add just a touch of aromatic or other munich like "malty" grain to the mix.

Think of it as similar to the difference between Maris Otter and 2-row. There is one, but it's subtle.

Since in a dubbel you probably are already doing this and/or adding candi syrup and/or similar like Big Papa said, you might not notice any difference in what your making.