I have been brewing lagers for the past couple of years in an attempt to dial in my process. I have been making what I think are pretty good beers but one specific homebrewer always says the lighter colored lagers I have made have a metallic character. My sister said the same on Christmas day and I kind of get it too. I have never had this complaint with my ales. I am using Diamond and 34/70 and have gotten the comments on both yeasts (Attenuation 75-82% on various batches).
Do you get this sensation in your lagers? What tips can you give to minimize the metallic taste in light colored lagers? I have a copper CFC that I whirlpool through (recirculate boiling water through before brew that gets the green oxide out) and some other copper elements in my system that I am considering as the sources of the taste, but again it isn’t present in my ales.
FWIW, I am mashing at 5.3 -5.4 ph and acidifying the sprge water to @5.5. I am using pretty soft Birmingham, AL water as 1/3 of the brewing liquor cut with 2/3 distilled. I use fresh malt from local breweries.
Advice or experiences? Should I get rid of all copper in my system / process?
You said that you found this flavor with “both yeasts” but also that it was when using 34/70, so I’m a little confused.
I find that 34/70 tends to have a tart flavor. Try switching to another lager strain, like Diamond, which in my beers accentuates malt flavors.
I doubt that copper is the culprit.
Does the brewer’s lagers that you buy malt from taste like metal? If so it could be improper lager malt storage
As far as copper: though many have used it for years without concern, I would remove it from the system. As you said it just corrodes too easy as well as can contribute to other problems for my brewery.
To eliminate water as a culprit you could brew a batch with 100% bottled water just to give you peace of mind.
It’s the only thing I can think of that Is different between Lager and Ale: the base malt. Equipment and water are common.
There are many references. Here is one:
“While metals should be suspect number one, it’s also possible to derive metallic flavors from improperly stored malt. The solution to this one is easy: Buy fresh malt from a reputable supplier, and store it in a cool, dry area.”
Just a thought: Most likely you store your Pils inside in a 55lb sack, plastic bucket or bag. IDK
However, while breweries can store 55 lb bags on pallets, larger ones can store larger qty of grains in (metal) silos outside. If this particular brewery has these silos for their Pils malt it could be the cause. Admittedly, pure speculation on my part.
Boiling water will probably only remove minimal copper oxide. One of the best ways to clean the inside of a copper coil is to circulate white vinegar for a few minutes and then flush with water. It’s basically the same process used to descale a tankless water heater for anyone that has one.
I was going to recommend the same, although I would expect to see the off-flavor in every brew (not just lagers) if there were metal ions present at a high enough concentration. Still this is easy insurance, and will make a huge improvement if metal ions are the cause. I’d add it to you mash water (in case the water source is contributing), and just prior to putting your chiller into your kettle.
Are you allowing the wort to come in contact with the counter flow chiller that has/had copper oxide on it (the green stuff)? Copper oxide is highly toxic, boiling water isn’t going to remove it. Cleaning with an acid will remove it and the copper will be bright, but how will you know if the copper oxide completely gone? The bright copper reacts to acids in the wort and goes into solution. Your copper should have a dull brown patina to avoid it reacting to acid, the green stuff is really bad and should be avoided completely.
I think the source metallic flavor is pretty obvious. Get rid of the copper unless you can keep it a dull brown.
I use 3 keggles (HLT, BK, MT) for the brew day and I ferment in a 10 gallon Corny keg.
The BK has a pickup tube and whirlpool “arm” of copper. MT is all stainless but there is copper tubing that carries the water from the HLT to my Phil Listerman brass whirly gig sparger (Circa 2002… a real antique that you old timers will remember). CFC and IC are copper.
All malt stored in sealed HDPE containers (Vittles Vaults and other similar). Most batches are WY Barke Pils malt. I don’t taste metal in the malt
I have loved my homemade copper CFC because hop pellets cannot clog it and I have always been worried that SS plate chillers would clog. Might be wrong? But the green oxide is definitely in my copper CFC and it seems logical that on my more delicate beers it could show up more in the taste. Any thoughts on plate chillers and clogs and / or stainless immersion chillers as part of my solution? Who is using these SS chillers and how effective are they vs copper? Also is it an expectation that pilsners can be a bit tinny??
I cannot see the inside of the CFC coil, but I run a boiling water loop through it for @15 mins while mashing to both pasteurize and to flush any green out of it (which some does come out). I also run boiling wort through the CFC coil at 15 mins left in the boil just to be extra safe. After use, I flush with water, drain as best I can, and store.
Lets say I were to run acid through it, would I then need to re-passivate it?
I don’t use a SS plate or immersion chiller but I do use my SS HERMS coil to chill by removing the hot water and replace it with cold and recirculating thru it. It takes ~45 min to an hour to get from boiling to pitching temp.
Personally I would remove all questionable copper from your process and go with SS.
As an additional precaution you can check your tap water.
I use this kit - Amazon.com
Getting a water report from your water company is not relevant, it doesn’t account for the copper pipes it goes though in your home.
I have very acidic well water that was turning the inside of some copper pipes in home greenish (Statue of Liberty color),
and leaching borderline unsafe copper levels in the home. The copper and PH levels are monitored periodically.
My whole home water filtration system has a large calcite tank that rises PH which is replenished by me annually,
or when PH is dropping. When the PH to the home is kept between 6.6-7.0, the copper levels drop well within safe levels.
You can find many articles online about unsafe copper levels in drinking water, and the very bad health effects.
Acidic water turns copper green, which in turn leaches copper into water. I personally wouldn’t be as concerned
with the taste of beer than possible high copper levels going into my body.
( Years ago I had a salt water fish hobby, and learned all about testing water for PH, Nitrite, Nitrate, Salinity, Copper,
Ammonia, etc…)
I know I went off on a tangent, but that’s my story and I’m sticking to it.
Time is one way to turn it brown, but from what I gather and have experienced is that a high pH solution will cause the copper to form a dull brown color and protect it from oxidizing. You could clean it/soak it in an acid solution to get it bright and then soak it in a baking soda solution or you could clean it with PBW to turn it brown again. The key is to get rid of the bright cooper and the green copper. Brown copper is the best for brewing and food safety in general.
You can Google how to put a brown patina on copper and a bunch of stuff comes up. Personally I stop using any copper in the brew system, but this isn’t always an option. Some of the stuff that needs to be replaced can be expensive
