Metallic flavor?

[IXVolt]

My oatmeal stout has a metallic flavor and I have no idea what caused it. It was my second AG batch, so my mashing wasn't as efficient or precise as it is now. I have good tap water, and I filtered it as well.

Any ideas?

 

[blackwaterbrewer]

i see you bottled it. a local brewery here in VA has recently had a coppery-metallic-penny-in-your-mouth- after taste. i have no idea why. maybe, cheap caps? rusty caps?

 

[ShortSnoutBrewing]

Metallic
Metallic flavors are usually caused by unprotected metals dissolving into the wort but can also be caused by the hydrolysis of lipids in poorly stored malts. Iron and aluminum can cause metallic flavors leaching into the wort during the boil. The small amount could be considered to be nutritional if it weren't for the bad taste. Nicks and cracks ceramic coated steel pots are a common cause as are high iron levels in well water. Stainless steel pots will not contribute any metallic flavors. Aluminum pots usually won't cause metallic flavors unless the brewing water is alkaline with a pH level greater than 9. Shiny new aluminum pots will sometimes turn black when boiling water due to chlorine and carbonates in the water.

The protective (grayish) oxides of aluminum can be enhanced by heating the clean pot in a dry oven at 250°F for about 6 hours.

How to Brew - By John Palmer - Common Off-Flavors

Could also be the yeast. To me, New Castle has a metalic flavor to it, and the clone I did as well. I associated it with the yeast.

 

[Yooper]

I've noticed that some of the beers that use darker malts have a metallic after taste for me, too. It's slight, but present. I've traced it back to my water chemistry (high residual alkalinity and hard water). If you can get a water report, that might help you quite a bit.

 

[IXVolt]

Good info.

I brew in a 15.5 gallon stainless keggle. I've brewed 6 batches in it thus far, and this is the only one that has the metallic flavor. Also of note, this is the only dark beer I've made so far. So I wonder if it could be a result of dark grain tannins?

The caps could be a possibility, they were fairly old. I was keeping them in a ziplock in the freezer. However I used the same caps for a batch of apfelwein and didn't have any metallic flavors.

The grain was crushed at my LHBS when I purchased it.

Yeast I suppose could have caused it. I forget exactly what I used, I'll look at my notes later and see if I can cross-reference it.

 

[ajf]

I've had a couple batches using Wyeast 1028 that had a very strong metallic flavor when they were green. In both cases, I left the beer for an extra 4 - 6 weeks by which time the off flavor completely disappeared.

-a.

 

[nate0075]

Yea thats my recommendation, Im on batch 22 using AG and everytime my beer had an "off" flavor or was maybe a touch too sweet, I would just leave it alone for about 2-3 weeks and it would seemingly fix itself!

 

[IXVolt]

This beer has been in the bottle for about 2 months now...

I have about 15 bottles left, so if nothing else I would just like to improve on it and continually make a better beer. I think it deffinately could have been the yeast I used. I think it might have been some sort of munich lager yeast, and I didn't have the fermentor at lager temps... perhaps that could be part of the reason.

 

[nate0075]

That will definately do it! After two months...thats the taste. You're done.