Metallic taste on finish of my stout

[olotti]

So this is the third time I've brewed this stout it's a founders breakfast stout clone sort of and I say that as I built my own grain bill based on a couple diff beast stout clones. Anyway it's a month in the bottle now and has nice color, head, and initial coffee attack from 2 weeks of coffee beans in the primary but on the finish there's this real metallic note I've never had before it literally tastes like I have penny in my mouth but as the beer warms and consecutive sips it's nowhere near as strong as the first sip. Any idea what is causing this and will it age out with time? If needed I'll post the grain bill but in a nutshell beer waspitched with dennys 50 and fermented at 68 then brought up to 70 to finish out for two weeks then I added the coffee beans in a cheesecloth sack for two weeks and then bottled. any idea what would cause this metallic flavor. It's been bottle conditioning for one month now at 72 deg.

 

[EcuPirate07]

Googled off flavors in beer, this help at all? More than likely it won't go away

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.

 

[olotti]

Googled off flavors in beer, this help at all? More than likely it won't go away

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.

Thank for the info I use an aluminum brew kettle that has been seasoned long ago and I brew ateast 2-3 Ris's a year and have never got this flavor but has weird is that's its prominent in the first sip but goes away after that. I can't imagine it's oxidized as I've seen that could be an issue but it's only been in the bottle a month and I have older he stout that don't have this flavor. Could it be a byproduct of the coffee bean acidity.

 

[sky4meplease]

What was your water source?
Outside of water I would add that a stout will seriously benefit from some aging. I have a couple stouts and a porter that are well over a year old and they just keep getting better.

 

[javert]

Have you tasted coffee made with such coffee beans? Those may be the ones giving it the off flavor.

Metallic flavor on coffee comes from beans that were roasted at high temperatures and way too quickly.

 

[oceanic_brew]

I have a dunkelweizen that I'm attributing the metallic taste it has to either the. We bazooka screen in my new mash tun, or an off flavor from potentially stressed yeast.

I also used homegrown hops for the bittering addition but can't see this being the issue.

I know I know, not a helpful response

 

[mattdee1]

Did you do anything different with your water this time around? One time I was brewing on a cold winter day and made the mistake of using hot water from my tap, thinking that it would speed up the process of getting to strike temperature, but I ended up getting a faint metallic taste in the beer from the hot water tank.

How's the carbonation? If it's on the high side, you might be tasting some carbonic acid. I doubt this is the issue, but it's a remote possibility.

 

[NSMikeD]

Did you do anything different with your water this time around? One time I was brewing on a cold winter day and made the mistake of using hot water from my tap, thinking that it would speed up the process of getting to strike temperature, but I ended up getting a faint metallic taste in the beer from the hot water tank.

How's the carbonation? If it's on the high side, you might be tasting some carbonic acid. I doubt this is the issue, but it's a remote possibility.

I was thinking that metallic can be confused with a light acid plus another flavor, especially something and complex as a stout. OP mentioned the coffee - which was my first thought - not uncommon for poor coffee roasting to produce acids that will appear as metallic to our palette.

One month is still young for a stout. It may be things the yeast hasn't gotten to, yet.

 

[jimmypop13]

I had a similar taste one. Ended up being star San. Now I rinse it off and the flavor has gone away

 

[olotti]

What was your water source?
Outside of water I would add that a stout will seriously benefit from some aging. I have a couple stouts and a porter that are well over a year old and they just keep getting better.

I use store brand bottled spring water for all my stouts and I've never had this happen, the water profile actually is perfect for stouts but horrible for everything else. I'm hoping this just ages out.

 

[olotti]

Have you tasted coffee made with such coffee beans? Those may be the ones giving it the off flavor.

Metallic flavor on coffee comes from beans that were roasted at high temperatures and way too quickly.

I used Starbucks cafe Verona coffee which I really like as a coffee but never used then beans before like this. Usually I use specialty beans from a local farmers market but figured I like the Starbucks coffee so I'd try that. I coarse crush 3 oz and use 2 oz whole beans soaked in vodka for 48 hrs and everything is added to primary. I'm hoping it's just coffee and it'll age out.

 

[Yooper]

Something I learned a long time ago is that black/roasted grains in a recipe can take on a metallic taste when oxidation is present.

I wish I could remember where I picked that up- maybe studying for the BJCP exam(?), but that still seems right to me.

So many people that oxidation means "cardboard" flavor, but that's not the case in the majority of the times I've tasted oxidation. It can be stale, or musty, particularly in lighter beers but in beers utilizing roasted grains it can taste metallic, particularly in the finish.

Amber colored beers may take on more of a "sherry" note, long before any 'cardboard' flavor is evident.

 

[Tiber_Brew]

Here's a trick I learned from Ray Daniels in a sensory workshop at the Michigan Brewers Guild Conference a few years ago. It's a trick to tell if the off flavor you're tasting is in fact metallic and of metallic source.

1. Smell the beer. Does it smell metallic? If so, it might be oxidation. If not, continue...
2. Dip your pinky in the beer and rub it on the back of your hand, then smell the back of your hand while it's wet. Now does it smell like metal? If so, you do in fact have a metallic source imposing the off flavor in your beer. Time to re-passivate your stainless or upgrade non-stainless process handling material.

Edit: after reading Yooper's response, it seems to validate one of the possible outcomes of the above test, so I'm curious to hear the results if you're willing to do so. I've not had the chance to perform this test since the conference because I've not had a metallic beer in front of me after that. I'm curious to see if it works as well as it did at the sensory workshop.

 

[Stillraining]

FWIW...your taste buds loose their sensitivity fairly quickly..hence your perception that it goes away after the first taste...it doesn't..just your ability to perceive it as accurately.

Nobody really likes 100 IBU beer ..they just dont perceive the bad taste anymore..

 

[olotti]

Here's a trick I learned from Ray Daniels in a sensory workshop at the Michigan Brewers Guild Conference a few years ago. It's a trick to tell if the off flavor you're tasting is in fact metallic and of metallic source.

1. Smell the beer. Does it smell metallic? If so, it might be oxidation. If not, continue...
2. Dip your pinky in the beer and rub it on the back of your hand, then smell the back of your hand while it's wet. Now does it smell like metal? If so, you do in fact have a metallic source imposing the off flavor in your beer. Time to re-passivate your stainless or upgrade non-stainless process handling material.

Edit: after reading Yooper's response, it seems to validate one of the possible outcomes of the above test, so I'm curious to hear the results if you're willing to do so. I've not had the chance to perform this test since the conference because I've not had a metallic beer in front of me after that. I'm curious to see if it works as well as it did at the sensory workshop.

Sure I'll try the test. It's possible it could be oxidation. I opened the lid on the bucket once to add coconut the other to add the coffee beans, I've never tasted oxidation in a stout but if it is I'm surprised that a) it took hold so fast and b) can overcome not only the bold flavors of the 9% stout but also the coffee.

 

[bkboiler]

i had this problem first time i used my aluminum pot...time to switch to SS

 

[olotti]

i had this problem first time i used my aluminum pot...time to switch to SS

I've been using this pot for 4 yrs with 10+ batches of stouts with zero issues like this ever and I seasoned the pot before I ever used for the first brew. I just think if It was the pot I would've had this taste before.

 

[olotti]

Here's a trick I learned from Ray Daniels in a sensory workshop at the Michigan Brewers Guild Conference a few years ago. It's a trick to tell if the off flavor you're tasting is in fact metallic and of metallic source.

1. Smell the beer. Does it smell metallic? If so, it might be oxidation. If not, continue...
2. Dip your pinky in the beer and rub it on the back of your hand, then smell the back of your hand while it's wet. Now does it smell like metal? If so, you do in fact have a metallic source imposing the off flavor in your beer. Time to re-passivate your stainless or upgrade non-stainless process handling material.

Edit: after reading Yooper's response, it seems to validate one of the possible outcomes of the above test, so I'm curious to hear the results if you're willing to do so. I've not had the chance to perform this test since the conference because I've not had a metallic beer in front of me after that. I'm curious to see if it works as well as it did at the sensory workshop.

Well drinking one now and to answer your questions:

A) no metallic smell on the nose, some coffee, roast maybe a little fusel from the alcohol.

B) Wow! Smells like a wet penny and it's unmistakeable. So if this is caused by my aluminum pot how could this happen all of a sudden. I've made everything for 3+ yrs with this pot and many stouts and russian imperial stouts and never had this flavor and all my stouts use the same water. Will this age out at all? And what do I do with the boil kettle from here on out, does this mean it's bad to make stouts in. I made a RIS back in December that's ageing on oak in secondary now, I may pull a sample and see if I get any metallic taste. Any thoughts on how this could happen all of a sudden or what my have caused this taste to leech into the beer.

 

[EcuPirate07]

Well drinking one now and to answer your questions:

A) no metallic smell on the nose, some coffee, roast maybe a little fusel from the alcohol.

B) Wow! Smells like a wet penny and it's unmistakeable. So if this is caused by my aluminum pot how could this happen all of a sudden. I've made everything for 3+ yrs with this pot and many stouts and russian imperial stouts and never had this flavor and all my stouts use the same water. Will this age out at all? And what do I do with the boil kettle from here on out, does this mean it's bad to make stouts in. I made a RIS back in December that's ageing on oak in secondary now, I may pull a sample and see if I get any metallic taste. Any thoughts on how this could happen all of a sudden or what my have caused this taste to leech into the beer.

Could have had a scratch or a cut or something you can't see but as you brew it leaches into the wort from the pot. Try switching out the pot. If that's the cause well damn that sucks it took this long. But at least you will know.

 

[olotti]

Something I learned a long time ago is that black/roasted grains in a recipe can take on a metallic taste when oxidation is present.

I wish I could remember where I picked that up- maybe studying for the BJCP exam(?), but that still seems right to me.

So many people that oxidation means "cardboard" flavor, but that's not the case in the majority of the times I've tasted oxidation. It can be stale, or musty, particularly in lighter beers but in beers utilizing roasted grains it can taste metallic, particularly in the finish.

Amber colored beers may take on more of a "sherry" note, long before any 'cardboard' flavor is evident.

Yoop, so I tried Tiber brews test see my post below and it's pretty crazy the wet sample on the back of the hand smells like wet metal. I mostly get like a coffee fusel/ alcohol on the nose which I'm not surprised for a 9% stout. I'm wondering if the well used and seasoned baking sheet I used to toast the coconut on could be the problem. Maybe some metallic flavor leeched into the coconut when I toasted it in the oven and that's causing the offlfavor, I steeped the coconut in primary for two weeks but get zero coconut flavor. As you know you've had some of my stouts before and they've never had any metallic taste that came from the pot so could the baking sheet be the source? Just spit balling here.

 

[olotti]

Could have had a scratch or a cut or something you can't see but as you brew it leaches into the wort from the pot. Try switching out the pot. If that's the cause well damn that sucks it took this long. But at least you will know.

Thanks for the thoughts. Would this fault in the pot impart any flavor in an IPA or pale ale?

 

[EcuPirate07]

Thanks for the thoughts. Would this fault in the pot impart any flavor in an IPA or pale ale?

I would assume all beers if it truly is the pot

 

[olotti]

I would assume all beers if it truly is the pot

So to confuse things even more I have a pale ale and dipa I made after this stout and I'm drinking the pale ale now and it's just a nice clean hoppy pale ale, zero metallic flavor at all. I mentioned this in my post to yooper and I toasted coconut for this stout on a well worn and seasoned baking tray and I wonder if coconut didn't pick up some metallic off flavor off of the baking sheet. I steeped the coconut for two weeks in cheese cloth but sadly no coconut is apparent on the taste, it did however leave floaties and kill the head retention. But anyway is it possible the metallic flavor could be from the baking sheet?

 

[Yooper]

So to confuse things even more I have a pale ale and dipa I made after this stout and I'm drinking the pale ale now and it's just a nice clean hoppy pale ale, zero metallic flavor at all. I mentioned this in my post to yooper and I toasted coconut for this stout on a well worn and seasoned baking tray and I wonder if coconut didn't pick up some metallic off flavor off of the baking sheet. I steeped the coconut for two weeks in cheese cloth but sadly no coconut is apparent on the taste, it did however leave floaties and kill the head retention. But anyway is it possible the metallic flavor could be from the baking sheet?

Boy, Dan, I really don't know. I wouldn't think so, but..............I really can't imagine what it could be if it's not the pot or oxidation.

 

[olotti]

Boy, Dan, I really don't know. I wouldn't think so, but..............I really can't imagine what it could be if it's not the pot or oxidation.

Thanks for the reply Lorena. If it is oxidation I'm just surprised I guess it took hold so fast in such a big beer. I did open the lid on the bucket once to put the coconut in at two weeks then put the coffee beans in a couple days later and they sat for two weeks so it was one month in primary before I bottled and I bottled with some CBC-1 just because the beer was sitting in primary so long. I'm stumped but beyond the initially metallic taste it otherwisectastes like a ris with coffee and maybe the plate adjusts so the metallic taste isn't so strong but it's def not as present after first sip.

 

[Tiber_Brew]

Well drinking one now and to answer your questions:

A) no metallic smell on the nose, some coffee, roast maybe a little fusel from the alcohol.

B) Wow! Smells like a wet penny and it's unmistakeable.

Neat test, eh? This confirms that it is of metallic source, and likely not oxidation.

So if this is caused by my aluminum pot how could this happen all of a sudden.

It's unlikely to have started suddenly, although I suppose it's possible. It may not be your Aluminum kettle, though. It could be brass valves, iron pipe fittings, rusted material at all in contact with wort, etc.

Will this age out at all?

No.

And what do I do with the boil kettle from here on out, does this mean it's bad to make stouts in. I made a RIS back in December that's ageing on oak in secondary now, I may pull a sample and see if I get any metallic taste. Any thoughts on how this could happen all of a sudden or what my have caused this taste to leech into the beer.

If all your beers had the same metallic off flavor, then maybe I'd pin it on your Aluminum pot or some of your fittings. But...

...a pale ale and dipa I made after this stout and... zero metallic flavor at all.

...I toasted coconut for this stout on a well worn and seasoned baking tray...some metallic off flavor off of the baking sheet...is it possible the metallic flavor could be from the baking sheet?

That's very possible. If by "well worn" you mean has deep scratches and rust, then it becomes an avenue for carrying iron ions to your beer. Especially if none of your other beers are exhibiting the same off flavor.

 

[spittybug]

Just a thought... In my all SS setup I just made a SMASH, Maris Otter and (the culprit I think) Magnum hops. I foolishly used them as bittering and flavor hops. I think the high alpha, but not floral/citrus/piney hops, if used late in the boil may be a culprit in producing an off flavor that MY palette construes as kind of metallic. I had this happen one other time when making another Maris Otter predominant beer (an English bitter). Maybe it is the MO somehow? I hope not, I love that grain.....

 

[olotti]

Neat test, eh? This confirms that it is of metallic source, and likely not oxidation.


It's unlikely to have started suddenly, although I suppose it's possible. It may not be your Aluminum kettle, though. It could be brass valves, iron pipe fittings, rusted material at all in contact with wort, etc.


No.


If all your beers had the same metallic off flavor, then maybe I'd pin it on your Aluminum pot or some of your fittings. But...


That's very possible. If by "well worn" you mean has deep scratches and rust, then it becomes an avenue for carrying iron ions to your beer. Especially if none of your other beers are exhibiting the same off flavor.

Thanks for the info. I have a very simple setup. So cooler mlt, a 10 gal aluminum bk and 5 gal I use for heating up sparge water and then an immersion chiller. I don't believe there's rust on the bakeing sheet but I'll check. I've drank lol a couple of the pale ales tonight and have again zero of that metallic taste and I even did the test again and nothing like with the stout. Idk if the roasted malts bring it out more, color me confused.

 

[Tiber_Brew]

Thanks for the info. I have a very simple setup. So cooler mlt, a 10 gal aluminum bk and 5 gal I use for heating up sparge water and then an immersion chiller. I don't believe there's rust on the bakeing sheet but I'll check. I've drank lol a couple of the pale ales tonight and have again zero of that metallic taste and I even did the test again and nothing like with the stout. Idk if the roasted malts bring it out more, color me confused.

My Vegas odds are on the cookie sheet unless it's not as worn as I imagine. One thing to note, however, is that beers with high roasted grain component tend to reduce the pH of the wort, which could increase leaching of metal ions from non-corrosive resistant metals. This may be a stretch, however.

 

[olotti]

My Vegas odds are on the cookie sheet unless it's not as worn as I imagine. One thing to note, however, is that beers with high roasted grain component tend to reduce the pH of the wort, which could increase leaching of metal ions from non-corrosive resistant metals. This may be a stretch, however.

I'm thinking it's gotta b the baking sheet, it's the only different variable between any of the stouts I made recently. I looked at it closely today and like I said it's well worn there are spots throughout where the enamel has worn off, it's not rusted, but maybe this caused the coconut to pick up some metallic flavors as it toasted. Well thanks for the replies and insight.

 

[Tiber_Brew]

Next time you could try one of those silicone baking sheets to toast coconut. If the metallic taste is gone, that pretty much confirms it.

Glad to help. Hope we found the issue.

 

[bkboiler]

tried to read entire thread to see if this was mentioned, but was your immersion chiller possibly the cause? it's copper i assume.

 

[Dunkelbiertrinker]

I've got a 9.5 % abv stout with the same unsettling flavor. Everything else about the bier is great. The smell, the creamy full mouthfeel etc, But that aftertaste is not nice.
I brewed on 10 Dec 2016. Bottled on 14 Jan 2017, I too used 50g whole organic espresso beans, 3 days into primary. It was my first time adding something after it's in the fermenter. So I baked the beans at around 200*C in the oven for 10 minutes. I didn't want to add any wild yeast or bacteria and ruin the Bier. Maybe I've inadvertently ruined ... well it's not ruined, but it takes a little getting use to, by the 3 bottle, one barely notices LOL, but maybe by baking the beans I added some extra acids that taste metallic.

Water from a special fountain in Switzerland. I used it for my very first bier (a Cooper's stout kit with mods) and it was delightful, everyone loved it.
Recipe:
1 Cooper's Stout kit.
500g dark brown sugar
454g Lyle's golden syrup
201g Molasses
OG 1.082 FG 1.009
primed: 160g DDME, 10g BDME, 10g table sugar in 1 liter boiled water, added to bottling vessel.
55 x .5 L bottles.