Different Mash Temps for specialty grains

[bellinmi88]

Would there be any benefit to mashing specialty grains at a higher temp if trying to achieve a certain sweetness profile with a beer.

Trying to attain that plum like character that Newcastle has but don't think mashing the full grain bill at a higher temp will do the trick. I am wondering what effect mashing the specialty grains at a higher temp would have on the finished beer. Say mashing the crystal malts at 157 and the base malt at 150.

 

[IslandLizard]

Aside from the crystallized sugars that get dissolved, Crystal Malt, depending on how darkly it was kilned has convertible starches left, the lighter ones having more (C10-C40 and the like). The darker ones (C120 and up) probably nil. So adding those lighter ones to the mash will give a few extra points, alas at a small total yield, since they are only a small grist percentage.

Now darker grains, mainly roasted ones may benefit from steeping at lower temps to avoid astringency and acrid flavor contributions. Actually adding the steeped dark (black) wort later in the boil, between 10' and flameout can prevent them taking on certain cooked coffee flavors.