Q:

Flaked Wheat vs Milled Unmalted Wheat

Flaked Wheat vs Milled Unmalted Wheat in beer brewing.
Does it make any difference to the brewing process or to the final product?

A:

If the grist contains unmalted grains, typically the brewing process is to first cook the grains to their gelatinisation point.  The gelatinisation temperature of wheat is about 51°C → 64°C (125°F → 147°F), which is a typical mash temperature.  So unmalted wheat should gelatise in the mash without any special treatment. 
As part of the flaking process, the grain is pre-steamed before going thorough heated rollers.  The steam (and rollers) will gelatinise the grain, so when including it in the mash no further processing needs to be done.  So one can just mash them with the rest of the malt.  
So it doesn't matter a whole lot for wheat, but it does for other grains/adjuncts like rice & corn (which have higher gelatisation temperatures).
Does flaked wheat Vs raw wheat make a difference?  I've not noticed any, but I only use non-malted wheat rarely.

