metallic taste

[jack13]

I am suddenly getting beers that have a metallic taste. That's the best I can describe it, and I've given it to a couple people and they have indpendently also used the word "metallic" to describe it (I didn't set them up at all--just gave them the beer).

In one case, it's so bad I plan to toss it (just putting it off until I need the keg it's in, which will be soon). Another wasn't metallic, but also very bad, which I tossed.

Research seems to indicate a metallic taste is due to exposure to metal, but a) I'm using all the same equipment I always have and b) I'm using the same water (RO + brewing salts as per beersmith).

I was thinking about it, and noticed a trend. After consulting my brew book, I found a strong correlation (see below) between the presence/absence of the bad taste and whether I used new or harvested yeast. I know there's no reason to think harvested yeast would cause a metallic taste, but thought this was interesting enough to share with fellow homebrewers.

Here's what I found for my last 11 brews (i.e., back to when I started kegging). Notice only one didn't fit the pattern.

Taste (Good/Bad) - Yeast (New/Harvested)
G - N
B - H (this one wasn't metallic tasting, but really, really bad--eventually tossed it)
G - N
G - N
G - H (only exception, but note I harvested this from the previous batch and used right away)
B - H (will toss)
G - N
B - H
G - N
G - N
B - H

I guess I'll not use harvested yeast for a few batches...but can anyone make sense of any of this?

To harvest yeast, I keep a little beer in the fermenter when I rack to keg, mix it up, then pour into jars. I use Mr. Malty to determine how much to pitch, but since I'm never sure of my 'Non-yeast percentage' or my "Yeast Concentration", I err (perhaps too much?) on the side of overpitching rather than risk underpitching. I think I do a decent job with sanitation when harvesting.

 

[nicksim86]

are the yeast storage jars glass or something else? do you have a lot of hop debris when you reuse it?

where are you getting your RO water? i've read stories of guys getting it from the grocery store and the filters need to be changed, so not really getting RO water.

have you changed your cleaning products? I've heard not rinsing PBW/oxiclean thoroughly enough can give a metallic taste. try cleaning your SS kettle and/or kegs with bar keepers friend to restore the protective non-reactive coatings.

do you use tap water with chloramine in it for cleaning and sanitizing?

 

[BrewKnob]

I am suddenly getting beers that have a metallic taste. That's the best I can describe it, and I've given it to a couple people and they have indpendently also used the word "metallic" to describe it (I didn't set them up at all--just gave them the beer).

In one case, it's so bad I plan to toss it (just putting it off until I need the keg it's in, which will be soon). Another wasn't metallic, but also very bad, which I tossed.

Research seems to indicate a metallic taste is due to exposure to metal, but a) I'm using all the same equipment I always have and b) I'm using the same water (RO + brewing salts as per beersmith).

I was thinking about it, and noticed a trend. After consulting my brew book, I found a strong correlation (see below) between the presence/absence of the bad taste and whether I used new or harvested yeast. I know there's no reason to think harvested yeast would cause a metallic taste, but thought this was interesting enough to share with fellow homebrewers.

Here's what I found for my last 11 brews (i.e., back to when I started kegging). Notice only one didn't fit the pattern.

Taste (Good/Bad) - Yeast (New/Harvested)
G - N
B - H (this one wasn't metallic tasting, but really, really bad--eventually tossed it)
G - N
G - N
G - H (only exception, but note I harvested this from the previous batch and used right away)
B - H (will toss)
G - N
B - H
G - N
G - N
B - H

I guess I'll not use harvested yeast for a few batches...but can anyone make sense of any of this?

To harvest yeast, I keep a little beer in the fermenter when I rack to keg, mix it up, then pour into jars. I use Mr. Malty to determine how much to pitch, but since I'm never sure of my 'Non-yeast percentage' or my "Yeast Concentration", I err (perhaps too much?) on the side of overpitching rather than risk underpitching. I think I do a decent job with sanitation when harvesting.

Not using an enameled canning pot for a brew kettle are you? Sometimes they chip and it can rust if the metal is exposed.

 

[jack13]

are the yeast storage jars glass or something else? do you have a lot of hop debris when you reuse it?

I use glass mason jars. Sometimes there is some hop debris, but not always. I started using a hop spider a few brews back. So hop debris is a possibility.

where are you getting your RO water? i've read stories of guys getting it from the grocery store and the filters need to be changed, so not really getting RO water.

I get Glacier RO water from the dispenser at the supermarket (Food Lion). There is an electronic readout that says when it's been serviced last, and it's always pretty recent (not that that's a guarantee, but reassuring). But for my last brew I decided to give the tap water a shot. First time doing that at my new house. My tastes good to start with, but I also ran it through a charcoal filter.

have you changed your cleaning products? I've heard not rinsing PBW/oxiclean thoroughly enough can give a metallic taste. try cleaning your SS kettle and/or kegs with bar keepers friend to restore the protective non-reactive coatings.

That sounds like a PITA but I'm more than willing if that has the potential to fix the problem!

do you use tap water with chloramine in it for cleaning and sanitizing?

I use glass mason jars to store harvested yeast. Sometimes there is some hop debris, but not always. I started using a hop spider a few brews back but haven't used any of those yet. So hop debris is a possibility.

I get Glacier RO water from the dispenser at the supermarket (Food Lion). There is an electronic readout that says when it's been serviced last, and it's always pretty recent (not that that's a guarantee, but reassuring). But for my last brew I decided to give the tap water a shot. First time doing that at my new house. My water tastes good right out of the tap, but I also ran it through a charcoal filter (slowly).

Getting inside the kegs with BKF sounds like a PITA but I'm more than willing if that has the potential to fix the problem!

I do use tap water for cleaning and sanitizing, but not sure about the chloramine content.

 

[jack13]

Not using an enameled canning pot for a brew kettle are you? Sometimes they chip and it can rust if the metal is exposed.

Nope, Bayou Classic stainless steel brew kettle.

 

[Saboral]

First I'd test the water to make sure you are indeed getting what you're paying for. Secondly, that hop spider, is that a bag or metal? I use a stainless hop spider, but it has to be thoroughly cleaned and passivated or it will tend to start showing signs of corrosion. Lastly, if all else fails I'd review your water additions. I know I have once or twice brewed a stout that I added to much in the way of alkalinity and while people described it as metallic it was too high in overall minerality causing that perception.

Oh and on an afterthought, are these beers being poured from capped bottles? I have definitely had my share of bottles with a rusty cap causing exactly your issue.

 

[jack13]

First I'd test the water to make sure you are indeed getting what you're paying for. Secondly, that hop spider, is that a bag or metal? I use a stainless hop spider, but it has to be thoroughly cleaned and passivated or it will tend to start showing signs of corrosion. Lastly, if all else fails I'd review your water additions. I know I have once or twice brewed a stout that I added to much in the way of alkalinity and while people described it as metallic it was too high in overall minerality causing that perception.

Oh and on an afterthought, are these beers being poured from capped bottles? I have definitely had my share of bottles with a rusty cap causing exactly your issue.

The hop spider is a DYI job, using a paint strainer bag.

And since you asked about water additions, this is another question I'm having trouble finding an answer to: If you're doing a 5 gallon batch, do you do additions for 5 gallons (e.g., enter '5 gallons' in beersmith), or do you do additions for all the water you use (for me, strike, infusion, and sparge water, which is 9+ gallons)? And should I do additions for all 3, or just the strike water?

I did not put any additions in my latest brew since I was using tap water and have no idea of its chemisty, so that could be revealing if that one turns out good. (Then again, if I ALSO scour the keg I put it into with bar keeper's friend as per another's suggestion...this is an annoying part of homebrewing. I could do one change at a time and maybe learn something, but in the end I want to maximize my chances of making a good beer. ugh.)

Regarding the cap thing: I keg now, so that's not it.

 

[Saboral]

And since you asked about water additions, this is another question I'm having trouble finding an answer to: If you're doing a 5 gallon batch, do you do additions for 5 gallons (e.g., enter '5 gallons' in beersmith), or do you do additions for all the water you use (for me, strike, infusion, and sparge water, which is 9+ gallons)? And should I do additions for all 3, or just the strike water?

So typically recommended practice is to add additions to the mash itself right after dough-in based on the strike water volume and than any sparge additions (aside from acid) to the boil kettle based on the amount of sparge water added to the runnings to get your preboil volume. Note that acid, if any, should be the only additive to the sparge water itself before hitting the mashtun.

I did not put any additions in my latest brew since I was using tap water and have no idea of its chemisty, so that could be revealing if that one turns out good. (Then again, if I ALSO scour the keg I put it into with bar keeper's friend as per another's suggestion...this is an annoying part of homebrewing. I could do one change at a time and maybe learn something, but in the end I want to maximize my chances of making a good beer. ugh.)

I’d be real careful with this, it’s going to be difficult to fully scour the inside of the keg, you may actually cause small scratches in the stainless and there are better ways to clean and passivate. I use a 20 minute PBW soak followed by a wipe down with a microfiber cloth and rinse, then an acid mixture (Beer stone remover from 5 Star), a rinse, and then sanitizer. Unless you are seeing pitting or rust on the interior of the keg I doubt it’s the keg surface imparting the metallic taste.

Regarding the cap thing: I keg now, so that's not it.

 

[MrHopScotch]

The thing that jumps out at me is that you are using harvested slurry without a starter, correct? If so, you might be severely under-pitching those batches.

Harvested yeast stored in the fridge loses viability FAST. Much faster than the vials or snack packs from the store. Even if you are pitching the recommended amount of slurry, you might have a lot less viable yeast in there than you think. How long are most of these stored before pitching?

The batch where you used the harvested yeast quickly to good effect seems to support this as well. If I am reusing yeast harvested this way, I usually try to pitch all the yeast in the jar within a week or so, if not sooner. Any longer than that, I make a starter using some, but not all of that slurry (remember, after a couple months it’s mostly trub and dead yeast). Even then, the starters seem to take an extra day to ferment out compared to a typical starter with fresh yeast.

When I plan ahead well enough, my preferred method these days is to simply overbuild my starters by 1/2 liter and save a portion of the nice clean starter wort, then use that for a starter for future batches.

Hope that makes sense!

 

[jack13]

The thing that jumps out at me is that you are using harvested slurry without a starter, correct? If so, you might be severely under-pitching those batches.

Harvested yeast stored in the fridge loses viability FAST. Much faster than the vials or snack packs from the store. Even if you are pitching the recommended amount of slurry, you might have a lot less viable yeast in there than you think. How long are most of these stored before pitching?

The batch where you used the harvested yeast quickly to good effect seems to support this as well. If I am reusing yeast harvested this way, I usually try to pitch all the yeast in the jar within a week or so, if not sooner. Any longer than that, I make a starter using some, but not all of that slurry (remember, after a couple months it’s mostly trub and dead yeast). Even then, the starters seem to take an extra day to ferment out compared to a typical starter with fresh yeast.

When I plan ahead well enough, my preferred method these days is to simply overbuild my starters by 1/2 liter and save a portion of the nice clean starter wort, then use that for a starter for future batches.

Hope that makes sense!

I usually end up pitching at least double what's recommended. The time the slurry is in the fridge varies, but I just checked and for the one with the worst metallic taste, the slurry was about 2 1/2 weeks old, which is on the younger side of how old it would usually be.

I don't typically use a starter, but actually did for the last 2. It remains to be seen how those taste...

 

[kbaggen]

The thing that jumps out at me is that you are using harvested slurry without a starter, correct? If so, you might be severely under-pitching those batches.

Harvested yeast stored in the fridge loses viability FAST. Much faster than the vials or snack packs from the store. Even if you are pitching the recommended amount of slurry, you might have a lot less viable yeast in there than you think. How long are most of these stored before pitching?

The batch where you used the harvested yeast quickly to good effect seems to support this as well. If I am reusing yeast harvested this way, I usually try to pitch all the yeast in the jar within a week or so, if not sooner. Any longer than that, I make a starter using some, but not all of that slurry (remember, after a couple months it’s mostly trub and dead yeast). Even then, the starters seem to take an extra day to ferment out compared to a typical starter with fresh yeast.

When I plan ahead well enough, my preferred method these days is to simply overbuild my starters by 1/2 liter and save a portion of the nice clean starter wort, then use that for a starter for future batches.

Hope that makes sense!

Hi there, did my last 15 brews though Fermentaours, and reused the yeast......I also store in jars, (and further a plastic bag with some alcohol too further limited bacteria growth on the outside part etc.), and I make a 24-hours vitaility starter as I no-chill. Hence, I also just as MrHopScotch think you might have used old yeast with low amount of living cells!

But besides that and also of importance, when I had metallic issues it all was connected too, a china-pump and various metals in the setup, hence, if you use metal-equipment in you brew system, only use one type, e.g. hence, do not mix brass with stainlesss steel, and hence I would reccomend you to limited any metal-parts as much as possible as if you have more than one type you can have eletrons moving eating away lower metals in the eletron-chain of metals when submerge in a liquid!

So do you do anthing different, put some additionaly metal parts into the mash than else? Hence, try make the overview with all additional equipment, and see if something differ!

 

[jack13]

Update on this metallic taste thing.

I've got more evidence now that it's coming from reusing yeast. Namely, a) I haven't had it again since I started this thread, and since then I've either used fresh yeast or reused yeast very soon after harvesting and b) I had some yeast in the fridge for about a month, and it smells very much like that metallic taste.

I'll be thinking about my method of harvesting and storing, and also do some research. One thing that comes to mind is that I used to rack off all the beer from the yeast cake, then pour in previously boiled water, but at some point I switched to instead just leaving some beer over the yeast cake rather than adding water.

In the meantime I'll just use fresh yeast, but I DO like harvesting (mainly just out of principle...why waste something if you don't have to?).

 

[Saboral]

Update on this metallic taste thing.

I've got more evidence now that it's coming from reusing yeast. Namely, a) I haven't had it again since I started this thread, and since then I've either used fresh yeast or reused yeast very soon after harvesting and b) I had some yeast in the fridge for about a month, and it smells very much like that metallic taste.

I'll be thinking about my method of harvesting and storing, and also do some research. One thing that comes to mind is that I used to rack off all the beer from the yeast cake, then pour in previously boiled water, but at some point I switched to instead just leaving some beer over the yeast cake rather than adding water.

In the meantime I'll just use fresh yeast, but I DO like harvesting (mainly just out of principle...why waste something if you don't have to?).

You could still harvest for near term reuse and be fine. For long term reuse and storage consider making slants which will keep significantly longer with less mutation and more consistency.

 

[jack13]

You could still harvest for near term reuse and be fine. For long term reuse and storage consider making slants which will keep significantly longer with less mutation and more consistency.

I don't know anything about slants, but am curious so will definitely read about that. But I still think something is wrong with my process of harvesting. Previous to first trying it (a couple years ago), I had read quite a bit, but I don't recall anything about having to use harvested yeast right away. Seems I have only a couple weeks to use mine (lately) until they're bad. Does my theory about switching from using water as the medium to beer sound plausible as the cause?

Regardless, I'm very excited to have found the likely cause of my bad flavor. Thanks to all for the information!