Slight Sourness in Wheat Beer

[SamInNJ]

Here is the recipe for my first AG brew (3gal batch).

Malt:
2.3% Acid Malt
40% US 2 Row
40% White Wheat
3.5% Crystal 20
14.2% Oats

Hops:
FWH, 12.7IBU Hallertauer
20m, 7IBU Hallertauer
0m, 1.1IBU Saaz
1/2 ounce Saaz dry hop

Yeast:
wyeast 1318 (london ale III)

Water:
built from distilled, 1g gypsum, 1g calcium chloride per gallon.


Bru'n water had me hitting a mash ph of 5.2, nothing seemed to go awry.


Fermented, primed, bottled. Finally drinking and the beer has just a touch of sourness in it. It's delicious, I'm really happy with the turnout, but can anyone help me figure out where the sourness came from? I love this beer but one of the best bits of complexity it has was an accident :/

 

[Yooper]

Here is the recipe for my first AG brew (3gal batch).

Malt:
2.3% Acid Malt
40% US 2 Row
40% White Wheat
3.5% Crystal 20
14.2% Oats

Hops:
FWH, 12.7IBU Hallertauer
20m, 7IBU Hallertauer
0m, 1.1IBU Saaz
1/2 ounce Saaz dry hop

Yeast:
wyeast 1318 (london ale III)

Water:
built from distilled, 1g gypsum, 1g calcium chloride per gallon.


Bru'n water had me hitting a mash ph of 5.2, nothing seemed to go awry.


Fermented, primed, bottled. Finally drinking and the beer has just a touch of sourness in it. It's delicious, I'm really happy with the turnout, but can anyone help me figure out where the sourness came from? I love this beer but one of the best bits of complexity it has was an accident :/

That tartness comes from the acid malt and I also notice a tartness in most wheat beers anyway- sort of a lemony flavor, not really sour.

The mash pH of 5.2 will give a tart finish to the beer.