[liquidbrewing]

So, I've got a Brown Ale that I've brewed a couple times and it's got a hint of sourness to the smell.  It tastes really good though.  But didn't smell like this before.   I've brewed it before and the only thing I changed was the base malt.  This time I used pilsner instead of 2-row,  and boiled hard for about 70+ mins.



Type: All Grain
 Date: 9/19/2011
Batch Size: 10.50 gal
 Brewer: LiquidBrewing
Boil Size: 15.00 gal Asst Brewer:  
Boil Time: 90 min  Equipment: My Junk 17.5 Gallon Cooler/ 15.5 Sanke Boil Keggle  
Taste Rating(out of 50): 35.0  Brewhouse Efficiency: 78.00
Taste Notes:  
  
Ingredients
 
Amount Item Type % or IBU
17.00 lb Pilsner (2 Row) Ger (2.0 SRM) Grain 74.73 %
1.00 lb Aromatic Malt (26.0 SRM) Grain 4.40 %
1.00 lb Caramunich Malt (56.0 SRM) Grain 4.40 %
1.00 lb Special B Malt (180.0 SRM) Grain 4.40 %
1.00 lb Special Roast (50.0 SRM) Grain 4.40 %
0.50 lb Amber Malt (22.0 SRM) Grain 2.20 %
0.25 lb Black Malt - Belgian Debittered (500.0 SRM) Grain 1.10 %
2.00 oz Galena [13.00 %] (60 min) Hops 45.0 IBU
2.00 oz Galena [13.00 %] (30 min) Hops 34.5 IBU
2.00 oz Galena [13.00 %] (0 min) Hops -  
1.00 lb Brown Sugar, Light (8.0 SRM) Sugar 4.40 %

 
  

[euge]

I've had a few Brown ales that smelled a little sharp. Try changing back tot he original malt and see if the hint of sourness disappears. It might just be a slight variation or an increasing sensitivity to the recipe.

[Joe Sr.]

My porter typically smells sour during fermentation, as does the stout which is currently in the fermenter.

Perhaps it's the dark grains? 

The porter is typically Windsor yeast while the stout is wyeast Irish ale yeast.

Neither of them tastes sour.

[FRACKER]

Is it in the bottle already? Amazing things can happen during conditioning, so if it's not in the bottle yet the smell might go away. If it is in the bottle and done conditioning, then just give it some time. Is there any astringency to the taste?

[jeffy]

My first thought on this was that the aroma of pils malt was misinterpreted as sour, but I thought I'd wait and see if anybody else had the same opinion.  Since I'm the only one, let me say that pils malt has an aroma and flavor distinct from other base malts and I can imagine someone interpreting it as sour.  Ask yourself if the sour aroma is more like lactic, citric, vinegar or something else.  If you can't really identify it as one of those, it may be just the aroma of the malt.

[seajellie]

I've experienced a strong sour-like smell from a czech pilsner I was fermenting, and also thought this might've been the OP's issue (nearly 100% euro pils malt in mine). I was doing an open fermentation experiment, and I thought for sure it had a lactic bacteria infection.

But the taste seemed ok at FG, so I kegged. It ended up great (though not different enough from the closed fermentation to merit the worry it caused me). I couldn't detect much, if any, sour odor at serving.

Afterwards I figured the smell must've been the saaz hops mixed with fermentation odors that I wasn't used to smelling from an open fermentation. Now thanks to Jeffy I'll add pils malt to the list of possibilities....

[euge]

I was told a while back not to really worry about strange smells. Live beer is a changing Thing and my experience is that as long as the beer tastes good then the smell will probably disappear fairly quickly.

[beer_crafter]

are you sure it's a sour smell and not like a sulfur smell?