Raspberries too long in secondary?

[jamesjoystick]

Hi guys,
I made an stout with raspberries in secondary. I was planning to keep them on secondary for a week, but I had to go on a work travel and because of that the raspberries were in the secondary for a month.

I racked the beer to keg today, the raspberries had turn to white and the taste of the beer was really sour.

Beer wasted?

 

[IslandLizard]

Fruit turning white is normal, color and flavor are extracted. But your beer may have turned inadvertently into a sour from some bacterial/wild yeast infection clinging to the fruit. Is it drinkable? A dark sour can be good.

 

[jamesjoystick]

I wasn't like super-sour, I just was surprised as I was expecting a smooth stout flavor.
It tasted like belgian fruit ale..
I'll have to see what is it like after carbonating...

 

[IslandLizard]

Don't forget, any sugars from the fruit have been fermented too, leaving the fruit's natural acidity and a dryer beer. Plus the water from the fruit has diluted the beer a bit too. Depending on how sour it is, it may not be infected. Infections often show some sort of pellicle.

Acetobacter can be your bug of choice here. Oxygen in the headspace makes them propagate, changing alcohol into vinegar, if that's the kind of sourness it has.