But fresh wheat beer, even the stuff made by the big breweries, has that ever so slightly sour taste. Lots of others here have made the same comment.
And what I believe you are tasting is the yeast and it's by-products.
Just because others post it, doesn't make it true.
I have made numerous wheat beers. My Hefeweizens and Dunkelweizens are close to 70% wheat, with no sourness. They do have the fruity, clovey, banana, sometimes almost spicy flavors associated with the yeast. I've used the popular yeast strains for traditional German wheat beers, equilvent to the White Labs 300, 351, and 380. The yeast can produce some tart flavors, but nothing I'd call sour. The American ones are closer to a Kolsch strain, that also flocculates poorly, leaving alot of yeast in suspension. Pyramid uses a lager yeast to the same effect.
I'm not trying to bash here, and I know the flavors we are all trying to describe, so maybe sour just isn't the right word. Maybe we need to be more descriptive in what we taste, and try to think of all the components that go into the complex flavors of beer and many different processes and points along the process where we can manipulate flavors. Grain bill, hop selection, hop schedule, yeast strain, pitching rate, aeration technique, fermentation temperature, water chemestry, and fermenter shape are just some of the factors that go in the finished beer's flavors. Saying that the wheat itself is what causes the sour flavors is a little simplistic. Is it clove, spicey, fruity? Is the bitterness woody, piney, minty, floral or citrusy? Let's expand our palate a little.
I'll close with a description from Beer Advocate about Wheat Malt. No mention of sour in there.
''
Wheat - Wheat malt, for obvious reasons, is essential in making wheat beers. Wheat is also used in malt-based beers (35%) because its protein gives the beer a fuller mouthfeel and enhanced beer head stability. On the down side, wheat malt contains considerably more protein than barley malt, often 13 to 18%, and consists primarily of glutens that can result in beer haze. Compared to barley malt it has a slightly higher extract, especially if the malt is milled somewhat finer than barely malt. European wheat malts are usually lower in enzymes than American malts, probably because of the malting techniques or the varieties of wheat used.
Unmalted wheat often is used as an adjunct by brewers who wish to enhance head retention and foam stability. It also contributes to the body or "palate fullness" of the beer. Its high content of proteins greatly enhances foam stability. Beers made from significant amounts of wheat adjuncts are likely to be light in flavor and smooth in taste qualities. Wheat adjuncts are used in the same manner as barley adjuncts; but unlike with barley, there is almost no husk in wheat. Thus, tannins are not much of a problem. The gelatinization temperature range for wheat is between 52 and 64ºC.''
http://beeradvocate.com/beer/101/malts
I'm done with this one, I'll leave it alone from here.
