Is this due to the glutinous endosperm in the wheat berry?
I always have lots of pure wheat gluten around the house. Being that I'm currently an extract brewer, a tsp worth of something I already have present in my house may be cheaper than going and driving to buy a small amount of grain. Also, I imagine the pure gluten powder would not impart any flavor, thus making it useful for head retention in all beers. Am I crazy?
Head retention mostly. Papazian also says it helps "lighten" a beer, although I'm not quite sure what he means. The average wheat beer is "heavier" than the normal Euro lager that I am surrounded with.
Careful what type of wheat you use, it can add to haze problems (if that really bothers you... Personally, I don't care about the clarity, so long as the beer tastes good)
yes, that's why they are used, along with flaked barley, wheat, corn, etc. not sure it really works. i used to add at least ¼ lb wheat malt to most of my beers. i love the flavor and it never hurt, but i'm not sure it really helped with head retention in comparison to my other beers.
you'd do better to do a protein rest for head retention.
Yes wheat does lighten beer just like rice. If you use 5 to 20 percent it will create less body in the beer. Any of you who have made a Hefeweisen (Wheat beer) know that they are very light bodied beers because they are usually 60% of the grist. If you experiment with various amounts of wheat you will notice the change in the finished beer.