What is causing the "Tart" flavor in my beer?

[Nickme23]

I've brewed Hefe, Wit, English Mild, Northern Brown, Cream Ale, American Brown, etc. I've used Continental Pils, Maris otter, and extract kits. Some of the guys in my club say Maris Otter and wheat make beer tart but I haven't found anything to support that idea. Could water chemistry be making my beer taste tart? Not sour, just a tart aftertaste. I can't figure it out... I am scrupulous with cleaning and sanitization. I keg my beer. Never bothered to mess around with PH or water chemistry. I can't think of anything else you guys are gonna ask about.

It's not infected, I am way over the top with sanitization since my first AG batch got infected with a little bit of lacto. (actually turned out pretty tasty haha)

I appreciate any ideas.

 

[Howie]

Are you absolutely certain that what you are tasting is "tartness," and not something else? Have other experienced brewers tasted it and concluded the same thing?

I ask because when I was a young brewer, I used to think a lot of my beers had a "tart" flavor as well. I realize now that what I was tasting was excessive fruitiness due to improper fermentation temperatures.

 

[Nickme23]

I've shared one of my english milds with some guys at one of my club's meetings and they tasted it as well. All of the last three brews I did have that same tart character. The english mild and northern english brown were brewed with wyeast 1099 whitbread. I pitched cold around 60 and let it warm up to 65, the ambient temp was 65 at high krausen so they were fermented on the cold side of the normal range for that yeast. The cream ale's starter crapped out on me so I used some nottingham properly rehydrated and pitched it at 55, let it warm up to 60 and held it there hoping for a nice clean low ester production during the growth phase. They all have this slight tartness.

I've fermented warm and gotten the same thing, cold, same thing. I really don't think it's ferm temp or sanitation. PBW for cleaning, 5-Star for sanitation.

I've asked people who weren't experienced tasters if there was a sourness or a tart taste and they've told me that it's barely there but that they wouldn't have noticed if I didn't mention it. So I'd say it's barely perceptible. Maybe I'm being too harsh of a critic when it comes to my beer but I want to know what is causing it and be able to control whatever has that effect on my beer.

*edit* And I'm not sure it's not something else I'm tasting but it's definitely not fruity esters making the tart taste. It's not unpleasant just bothers me that I don't know what it is.

 

[Zamial]

Are these extract beers? if so, it could be extract "twang" it is common.

You say you started AG brewing. What temps are you mashing out at? are you sure your thermometer is accurate/calibrated? are you brewing in a bag and lifting the bag out or squeezing it?

This sounds remarkably like tannis/tannids to me.

 

[downinit]

An excerpt from a good resource for troubleshooting off flavors in beer:

ASTRINGENT

CHARACTERISTICS: Unlike bitterness, astringency is present as a stimulation of the nerve endings throughout the mouth. It is not an aroma. The taste is a puckering, dry, unpleasant situation. It is a very acidic, tannic, tart sensation reminiscent of grape skins.

CAUSES: Bacterial contamination (lactobacillus and acetobacter); added astringency from grains or hops.

PROCESS: Caused by: poor sanitation; excessive hopping; excessive wort attenuation (small dextrin content) giving greater perception of astringent; boiling grains; excessive grain crushing; too high a lauter run-off temperature (170 degrees max); to much run-off in lautering; letting beer sit too long on trub; non-blowoff primary fermentation; alkaline mash or runoff water; too much sulfate, magnesium or iron; excessively high acidity.

REDUCTION: Process changes to eliminate the above. Crack grain properly, watch mash/runoff pH, 170 degrees maximum for lauter runoff water, use blowoff fermentation; good sanitation practice.

http://www.kroc.org/Links/TroubleshootingGuide.htm

 

[Nickme23]

I normally get much higher extraction and efficiency than I should, but I just got a Barleycrusher malt mill so that should be slowly getting dialed back to a lower number as I figure out the right spacing for my crush. I never use a blowoff except for a hefeweizen cause I never really need it. Then it comes down to the water chemistry, and I know my water is pretty acidic and probably has a lot of Iron in it too... I guess I need to start checking mash and runoff pH. I figured it might be something like excessive tannin extraction. Most of the beers I have been brewing use some pretty dark malts. Thanks for all the help everyone!