I made a kiwi wheat beer that is a bit tart. How do I know it's not an infection?

[BrewVerymore]

So I made a wheat beer that I threw kiwis into during secondary and kept it there for 5 days. The ate abotu 3 of the kiwis and I don't recall them being too tart. Just "normal" tart/sweet level. I fermented with WB-06 and tried to keep temp down because I didn't want too much banana-flavored esters to come through.

The beer has a noticeable tartness that I would consider light to mild. It's more than manageable and I am on my 3rd glass in about an hour. The beer doesn't have any offensive smells that I can detect, but my beer nose/ palette is also not that refined. In fact, I don't know if I have ever smelled or tasted an infected beer so I have no reference point.

How do I know if this tartness is from the kiwi or from an infection?

Oh and I used about 14 pounds of sliced kiwi for 13 gallons. I should also mention that when it came time to rack, the top of the beer was clear of any film and had nothing growing on it. I carbed it for 5 days before testing (now).

 

[microbusbrewery]

Kiwis have a fair amount of acid in them and when all the sugar is fermented out, it becomes more apparent. Did you bottle or keg? If you bottled and there actually is an infection, you might see a pellicle or a bit of a ring form in the neck of the bottle. If you leave a bottle out at room temp for a few weeks, that speed the process (if it has an infection). The only way to really know for sure is to streak it out and see what cultures grow, but that takes some extra equipment. My guess is you're just getting acidity from the kiwis.

 

[BrewVerymore]

My guess is you're just getting acidity from the kiwis.

Thanks for the response. I didn't think about the fact that the sugars could've fermented out and left behind the tartness/acidity. I kegged these beers in sankey kegs by the way.

 

[passedpawn]

I made a kiwi wit in 2010. I do not rememember any tartness from it, just the fruitiness.

My tasting note

"light-bodied, very noticeable kiwi presence. I wouldn't lessen this at all, but I think a quarter ounce more of bittering hops would balance better. Very low carbonation (young!)"