I am new to the home brewing scene and tried my first go at it with a Hefeweizen Extract kit from my local brewing supply store. First off it seem to go very well or at least I thought. Fermentation seem to last about 3 days and I left it in the primary for 14 days…transferred to my bottling bucket and added priming sugar…bottled and let sit for another 10 days…tried it out and found that the carbonation was on point but I found that it was really dark for that style and had somewhat of a metallic after taste. Now i did use an aluminum brew kettle that was brand new and I didnt know I had to season it. I pitched my yeast at around 78 degrees and also my ABV was 3.9% which is lower than the instructions said (4.7 to 5.6). Any ideas where I went wrong and what I can do different?
“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.” John Palmer, How to Brew
I’ve been using aluminum kettles and HLTs for over a decade and never had them impart off flavors. Palmer also notes that aluminum will not, on its own, corrode or impart metallic flavors under the pH and temperature conditions encountered in brewing; it is quite nonreactive under a pH of 9.0, and he explains why even galvanic corrosion in conjunction with other metals is not normally an issue in homebrewing. But don’t clean it shiny, let it acquire a dull gray oxide layer. Then it is totally passive.
(My most recently acquired aluminum pot came with manufacturer’s instructions not to treat or season it in any way, as it had been specially treated to passivate it at the factory.)
I was thinking that too. Also, other minerals can present as what I, lacking the vocabulary of a trained beer judge, might call “metallic.” Changing the water source is a great place to start. If the beer improves, you may want to consider avoiding using your tap water in the future.
The dark color of the beer is most likely due to oxidation. Presumably at this point in your brewing career you aren’t able to avoid oxygen exposure – using basic fermenters, bottling from a bucket and such. At this point I wouldn’t worry too much, but start becoming aware of the effects of oxygen.
Were the bottles clean? Any detergents used to clean them ect? I also doubt it was the aluminum kettle. It is odd that the ABV was lower than anticipated. I wonder if it was a bad kit. When I was extract brewing I had my best results with the darker styles, porters and stouts. But that’s neither here nor there. I think it’s time to start a new batch is what I’m getting at.
You guys are missing one other potential cause. If the water used to reconstitute the extract had much alkalinity, the resulting wort pH would be higher than desirable and that increases the color and tends to make the resulting beer taste duller.
Water matters when brewing extract brews…just like with mashing. There are plenty of easy ways to improve your outcome when extract brewing. Use RO or DI water to reconstitute your wort or acidify the tap water to neutralize excess alkalinity.