So, the answer was copper

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So, the answer was copper

Postby Bagasso » Sun Oct 09, 2016 1:27 pm

The question was, how do I get rid of a musty odor that comes through my entire run?

No matter the recipe. ABV of 10% or lower. Running low and slow, drips, breaking trickle, pencil thick stream. It always seem to be there.

The reason, of course, were sulfur compounds.

The problem is that I have over 10 feet of cooper coil in my still and I use copper off-cuts as boiling chips. That should have been enough to take care of it so I thought "it couldn't be that". Friday I took a couple inches of 3/8 tube and dropped it in 100ml wash. Left it alone for a couple hours and that was it.

I then took a 6 inch piece of 3/8 tube and placed it in 2l of wash. Checked it every hour and it wasn't until 7 hours later that I was unable to detect the smell. That is a long time and probably the reason why the problem isn't handled by the copper in the still.

I was doing some airing out of 250 ml of wash with an air pump, hoping to gas off the funk but it didn't work. Dropped the bit of 3/8 tube. It's been 2 days and copper is not clearing it up. The only exposure was to air but once thiols are formed no amount of copper or time seems to help.

Some people don't ever seem to have this problem and I figure it could be the copper content of their water (copper water pipes or copper in well water) and even grains might be taking care of the problem in the fermentor. That might be a better place for copper than in the still.
Last edited by Bagasso on Sun Oct 09, 2016 10:13 pm, edited 3 times in total.
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Re: So, the answer was copper

Postby Bushman » Sun Oct 09, 2016 1:33 pm

Glad that solved the problem for you, I have a stainless steel column but it is packed with copper mesh, I have a copper dephlagmater and my whole return including my product condenser is copper so it has never been a problem for me.
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Re: So, the answer was copper

Postby Bagasso » Sun Oct 09, 2016 1:55 pm

Bushman wrote:Glad that solved the problem for you, I have a stainless steel column but it is packed with copper mesh, I have a copper dephlagmater and my whole return including my product condenser is copper so it has never been a problem for me.

Thanks but the thing is that I actually have copper in my still and it, apparently, has never done enough. I even started using copper boiling chips to get clean copper exposed to the wash in the boiler.

I know that in the US the FDA has set a limit of 1.3mg/l of copper in drinking water so chances are that many people incorporate copper into their pot still or toss a copper scrubbie on top of lava, marbles, ss scrubbies just in case but they probably never really had a sulfur problem to begin with because of the copper in their fermenting water.

I just wanted to share that while copper does act on sulfur compounds, the amount of exposure during distillation might not be enough in some cases, while others with SS kegs and only a few feet of copper exposure in their liebig might never have this problem.
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Re: So, the answer was copper

Postby der wo » Sun Oct 09, 2016 11:51 pm

I believe your observation with the copper. Was it a fermenting wash or a finished?
But why so much sulfur smell is developed? Only because your water perhaps contains no copper? Do you use yeast nutrients? I often had sulfur smell at the first two days of fermentation. Since I use nutrients it smells good also those first days.
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Re: So, the answer was copper

Postby NZChris » Mon Oct 10, 2016 12:40 am

Where is the sulfur coming from?

BTW, copper in the Liebig doesn't help as it's in the downward path and everything in it ends up in your jug.
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Re: So, the answer was copper

Postby der wo » Mon Oct 10, 2016 1:03 am

NZChris wrote:Where is the sulfur coming from?

BTW, copper in the Liebig doesn't help as it's in the downward path and everything in it ends up in your jug.

Sounds reasonable. But the truth is perhaps different:
http://onlinelibrary.wiley.com/doi/10.1 ... 0450.x/pdf
"copper was found to reduce the level of this compound best when placed in the wash still condenser or spirit still pot." About DMTS (dimethyl trisulphide) in double potstill distillation of malt whisky.

Yeast stress can cause sulfur smell. For example wrong temps, pH or lack of nutrients.
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Re: So, the answer was copper

Postby NZChris » Mon Oct 10, 2016 1:30 am

Copper was separately placed in
individual sections 1–6 of the stainless steel stills. The
levels of sulphury and meaty aromas in each of the new
make spirits produced are shown in Fig. 4. The level of
sulphury aroma was particularly high when copper was
placed only in the spirit still condenser (S6). Indeed, in
this case the sulphury aroma level was similar to the full
stainless steel still new make spirit.


The Impact of Copper in Different Parts of Malt Whisky Pot Stills on New Make Spirit Composition and Aroma
Barry Harrison*, Olivier Fagnen, Frances Jack and James Brosnan
J. Inst. Brew. 117(1), 106–112, 2011
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Re: So, the answer was copper

Postby der wo » Mon Oct 10, 2016 1:40 am

Yes, it's strange. Why it works in the wash still condenser, but not in the spirit still condenser?
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Re: So, the answer was copper

Postby Bushman » Mon Oct 10, 2016 5:21 am

This has been very informative, thanks for the responses and also to Baggasso for starting the topic.
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Re: So, the answer was copper

Postby Bagasso » Mon Oct 10, 2016 6:40 am

der wo wrote:Was it a fermenting wash or a finished?

It was finished and starting to clear.

But why so much sulfur smell is developed? Only because your water perhaps contains no copper? Do you use yeast nutrients? I often had sulfur smell at the first two days of fermentation. Since I use nutrients it smells good also those first days.

Yes, I always use nutrients. Different things over the years like tomato paste, boiled yeast, 20-20-20, wheat germ, bran. Sometimes alone and sometimes mixed. I've done panela washes that other people say they don't need to add nutrients too. Tried different yeasts as well.
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Re: So, the answer was copper

Postby Bagasso » Mon Oct 10, 2016 7:11 am

NZChris wrote:Where is the sulfur coming from?

From what I understand it is a normal by-product from the yeast.

BTW, copper in the Liebig doesn't help as it's in the downward path and everything in it ends up in your jug.

That would be the whole ethyl carbamate issue but, since some stillers will only give up their copper when they pry it from their cold dead hands, let's just all agree that a second run takes care of that.

Also, the wash with the copper sitting in it also had everything in it but not the funk.
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Re: So, the answer was copper

Postby Bagasso » Mon Oct 10, 2016 8:30 am

NZChris wrote:The Impact of Copper in Different Parts of Malt Whisky Pot Stills on New Make Spirit Composition and Aroma Barry Harrison*, Olivier Fagnen, Frances Jack and James Brosnan J. Inst. Brew. 117(1), 106–112, 2011

Read it but you have to look at the whole thing. OK, I'm also guilty of just now taking a closer look. First, they talk about two attributes, meaty and sulfury. Interesting is that they seem to mirror what is considered feinty and in figure 2 it shows where SS ends up with this flavor profile.

Here is an important bit:
However, it was found that the positioning of the copper in the stills had a large effect on the ability of the copper to reduce the level of DMTS in the new make spirit and placing copper in any single section was unable to replicate the effect of the full copper stills.

So more copper = better but from what I noticed with copper in the wash was that less copper for more time also made a difference.

Time of course is limited during a run but not while clearing. I'm thinking of placing a spiral of copper wire, maybe 20 or 30 cm of 20 AWG, in my fermentor. I know copper can be toxic to yeast but maybe just a bit won't bother them. Like a zoombot, sweeping up stray sulfur while they work.

There was found to be opposing trends in the wash and spirit stills. In the wash still, the pot (S1) was the least effective at reducing DMTS whilst the condenser (S3) was most effective. In the spirit still, the pot (S4) was most effective and the condenser (S6) was least effective. The most effective sections for reducing the DMTS level were there-fore the wash still condenser and the spirit still pot (S3 and S4).

This made me think of people who butt heads about single footing or doing a strip then the spirit run. Maybe some need both runs while others don't.
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Re: So, the answer was copper

Postby NZChris » Mon Oct 10, 2016 1:04 pm

Bagasso wrote:This made me think of people who butt heads about single footing or doing a strip then the spirit run. Maybe some need both runs while others don't.


My bad, I didn't realize you were trying to 'fix' a single run. I can't think of a single product I make that would be better for having only had a single run, slow or fast. I knew before I built my still that the people who made the products I liked to drink made them in pot stills with at least two passes, so I've never taken a lot of notice of what I'm getting throughout the strip runs except for the first couple thirty years ago that confirmed that the spirit run was far superior.
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Re: So, the answer was copper

Postby Bagasso » Mon Oct 10, 2016 1:50 pm

NZChris wrote:My bad, I didn't realize you were trying to 'fix' a single run.

I didn't say anything about me fixing a single run. I'm talking about others who say they don't see a difference in doing more than one run being contrary to what you posted.

I'm just sitting on the side listening to both thinking "could they both be right, and not just because of preferences?"

ETA: I think you also missed the quoted text. Copper in the condenser is better in the stripping run and copper in boiler is better in the spirit run. That is something that seems to be glossed over when this paper gets cited as support for the argument that copper is best in the vapor path.
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Re: So, the answer was copper

Postby NZChris » Mon Oct 10, 2016 7:24 pm

Bagasso wrote:ETA: I think you also missed the quoted text. Copper in the condenser is better in the stripping run and copper in boiler is better in the spirit run. That is something that seems to be glossed over when this paper gets cited as support for the argument that copper is best in the vapor path.


Yeah I had missed that. I've got it now. I've always had copper everywhere and don't let a distillation start in less than 45 minutes to give time for good things to happen. The preheater coil is copper, and that heats the next charge for the whole strip, which is always over an hour.

I'm in the process of building a new copper still head solely for spirit runs of flavored products. I could use an SS condenser on that and reserve my flash new copper one for stripping.
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Re: So, the answer was copper

Postby Bagasso » Mon Oct 10, 2016 8:22 pm

NZChris wrote:I've always had copper everywhere and don't let a distillation start in less than 45 minutes to give time for good things to happen. The preheater coil is copper, and that heats the next charge for the whole strip, which is always over an hour.

I don't want to sound rude and maybe it was my fault for naming the thread like I did but the thread isn't about asking "What works for others" because we already know that.

I want to know "Why running tried and true recipes at least twice in a still with copper in the pot, a short copper riser and 10 feet of coil on the down side isn't working for me while it seems to work for everyone else?"

Today I tossed my copper "boiling chips" and wash into my boiler around noon, let sit for 8 hours and fired the still up about 2 hours ago. Now I seem to be getting what others describe.

There is still that one tidbit in the article about a copper part on an SS still not matching an all copper rig. So there seems to be room for improvement but, what if an all copper rig isn't the limit either? What if it could all be cut out in the fermentor?
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Re: So, the answer was copper

Postby SaltyStaves » Tue Oct 11, 2016 12:46 am

Bagasso wrote:I even started using copper boiling chips to get clean copper exposed to the wash in the boiler.


You need a patina to bind sulfur components. Otherwise it behaves exactly like SS.
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Re: So, the answer was copper

Postby NZChris » Tue Oct 11, 2016 12:49 am

Bagasso wrote:I want to know "Why running tried and true recipes at least twice in a still with copper in the pot, a short copper riser and 10 feet of coil on the down side isn't working for me while it seems to work for everyone else?"


It sounds like you are doing everything right in the distilling department. That being the case, the problem is more likely to be in the wash.
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Re: So, the answer was copper

Postby NZChris » Tue Oct 11, 2016 1:01 am

Something that might be throwing me off is 'musty' as your description of the fault. I've never had a fault I would describe as musty. Might there be a better description?

Are you sure there is no synthetic anywhere in your setup that might cause 'musty'?
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Re: So, the answer was copper

Postby der wo » Tue Oct 11, 2016 2:22 am

SaltyStaves wrote:
Bagasso wrote:I even started using copper boiling chips to get clean copper exposed to the wash in the boiler.


You need a patina to bind sulfur components. Otherwise it behaves exactly like SS.

That's not 100% true I think. Of course copper oxide is solved much easier by the acids of a mash than clean copper, so an oxidized copper boiler or oxidized boiling chips would bring more copper into the mash, but in the vapor path and the condenser, the oxide is also very unsoluble.
Professional distillers at least in my country clean the copper with acids to "activate" it for better sulfur reduction.

I have the feeling I can improve something with the ideas here. Thank you Bagasso and all other writers!
Sorry for my bad English!
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Re: So, the answer was copper

Postby SaltyStaves » Tue Oct 11, 2016 3:26 am

der wo wrote:That's not 100% true I think.


"When used for the first time, the laboratory copper stills produced a spirit with a relatively sulphury and meaty aroma. Several repeat distillations were required prior to the start of this experiment to reduce this aroma suggesting that some corrosion of the copper may have been required in order to activate it. The actual mechanism of sulphur compound removal, however remains to be eluciated."


Inconclusive and only relates to a whisky that was fermented off the grain.
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Re: So, the answer was copper

Postby der wo » Tue Oct 11, 2016 5:31 am

Yes, it is not 100% clear. I don't think, there is a difference between whisky on or off the grain or a brandy. If you have fermenting yeast, you have sulfuric compounds. Probably more or less depending on circumstances.
Perhaps a patina is beneficial in the boiler, we know it gets solved by the acidic mash. But in the vapor path and the condenser, I am not sure.
http://www.a-holstein.de/index.php?id=182
"Blank copper with the largest possible surface areas forms the foundation for optimal results...In both the helmet and still, integrated cleaning units ensure blank copper and a fully developed, pure, unadulterated aroma"

In German:
http://www.brennerei-wissen.de/brennereireinigung.html
"Wichtig ist das Verständnis des zweiteiligen Reinigungsvorgangs:
Zuerst wird mit einem alkalischen und dann mit einem sauren Reinigungsmittel gereinigt.
Alkalische Reinigungsmittel bilden in Wasser gelöst eine hochwirksame Lauge (Verätzgefahr!). Diese löst Maischeanhaftungen sowie Eiweiß- und Fett-Verbindungen. Das saure Reinigungsmittel, im Normalfall Zitronensäure, neutralisiert das alkalische Reinigungsmittel, löst Kalkschleier und aktiviert die Kupferoberfläche."

Translated: Two stages cleaning process...first a hot basic...then an acidic, which...activates the copper surface.

Later they write sodium hydroxide for the first cleaning and citric acid for the second.

"Sauberkeit zahlt sich aus ...und zwar in der Qualität der Destillate.
Kupfer ist nicht nur hervorragend wärmeleitend und geeignet um Brennblasen und Helme zu formen viel entscheidender ist die Eigenschaft des blanken Kupfers Schwefelverbindungen (entstanden z.B. durch abgestorbene Hefezellen) zu binden. Katalysatoren verstärken diese Eigenschaft der Brennerei durch ihre große Oberfläche natürlich beträchtlich. Diese blanken Kupferoberflächen müssen vom Brenner mehrmals in der Saison hergestellt werden."

Translated: Cleanness...result in quality of the distillate...the ability of blank copper to bind sulfuric compounds (for example from dead yeast). Catalysts increase this effect due to the larger surface by far. Those blank copper surfaces must get cleaned multiple times per season.

I don't claim it's 100% true, that clean copper is better. I only want to say the recommendations are very contradicting.
So eiter one is right and the other is wrong or it is more complicated. I don't think one is right and the other wrong, because distilling with copper stills is a long tradition, unbelievable that one is 100% wrong.
So I think it is more complicated.
Sorry for my bad English!
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Re: So, the answer was copper

Postby Bagasso » Tue Oct 11, 2016 6:04 am

NZChris wrote:It sounds like you are doing everything right in the distilling department. That being the case, the problem is more likely to be in the wash.

Well tried and true recipes, making sure ABV is kept low (10% or less) and yeast have sufficient nutrients. Yeast has been bakers because it is all I can get in my country but it has included Red Star dry and fresh and a few other brands have been tried. Pitched in small amounts up to half a cup per 20L batch to see if the amount of yeast made any difference.

Let wash clear to crystal and have also run as soon as the hydrometer calls it .990. Measure pH (with a Hanna digital pH meter) to make sure it is around 4.5 to 5. Keep things clean to avoid infections (have only had 1 or 2 in all these years).

Have tried filtered tap, well, RO and even distilled water.

To answer your other post: No synthetics. SS, copper and flour paste. Besides, with the 8 hour soak of copper bits before distilling in the same still there was a marked difference.

As for whatever "musty" is, it has been cleared by exposure to copper so, it is more than likely a sulfur compound. I'm guessing as complex as a wash is, it is a mixture of things. I think a meaty and sulfury with a touch of moldy would describe it but I honestly don't think that helps much. It could be what some call sugar bite, or even a major component of tails. Musty like wet dog, wet cardboard or dirty socks could be how others describe it.
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Re: So, the answer was copper

Postby Bagasso » Tue Oct 11, 2016 6:09 am

SaltyStaves wrote:You need a patina to bind sulfur components. Otherwise it behaves exactly like SS.

Listening to advice like this for years has gotten me nowhere. My coil has had years to build a patina and I don't do anything other than wash out with plain old water between runs. It has a patina and it has never been enough.

Last night I soaked copper in my wash for 8 hours before running. Of course I had to open the boiler and take a whiff before sealing and running. It smelled cleaner and the distillate was also cleaner. Needless to say, soaking copper parts in acidic wash exposes clean copper and that made a difference so it certainly does not act like SS.
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Re: So, the answer was copper

Postby der wo » Tue Oct 11, 2016 6:25 am

Bagasso,
what do you think about cleaning your still with an acid before your next run? Perhaps it has the same effect like soaking copper in the mash. Or not or negative side effects.

Personally I always clean my still. Not with acids, so my still is patinated. But always with hot natron, especcially the packing (ss).
Sorry for my bad English!
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Re: So, the answer was copper

Postby Bagasso » Tue Oct 11, 2016 6:54 am

der wo wrote:Bagasso,
what do you think about cleaning your still with an acid before your next run? Perhaps it has the same effect like soaking copper in the mash. Or not or negative side effects.

I think there are two interdependent variables; how much does the wash need to be cleaned and how much cleaning can the copper in the still provide?

Like I said before, I got into the habit of placing copper pieces in the boiler so that the wash could be exposed to clean copper but the few hours that it took to complete a run never seemed to be enough exposure for my particular problem.

There was a mixed exposure to copper in those runs because the copper bits in the boiler would be cleaned by the acidic wash and the coil had copper patina and there was always the fault in the distillate.

I've heard people say that they don't like the taste of their distillate run through a new still because of the clean copper and that it takes more than a few runs to get the "new copper" taste out. Don't know if that is on the up-side or the down-side or if that makes a difference.
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Re: So, the answer was copper

Postby der wo » Tue Oct 11, 2016 7:28 am

We have two contradicting opinions:
1. Clean copper results in a metallic "new still" taste. Only patinated copper is able to clean the distillate from sulfuric compounds.
2. A still must regularly cleaned with acids, because only a clean still can produce a clean taste. Only blank copper is able to clean the distillate from sulfuric compounds.

Questions, which would allow answers, that both are right partially:
- perhaps some places should be blank, other patinated? For example upper path vs downer path? Or acid environment (boiler) vs neutral but high abv environment (vapor path and product cooler)?
- Would be a thin patina best? For example because it has neither the new copper taste nor a thick layer musty tailsy flavors from previous runs.
- is a fresh acid-cleaned old still the same like a new still?
Sorry for my bad English!
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Re: So, the answer was copper

Postby Bagasso » Tue Oct 11, 2016 8:17 am

der wo wrote:We have two contradicting opinions

Of the two contradicting opinions one is true. Clean copper reacts. Now chemistry can be very complicated and I'm in no position to say whether copper patina actually does anything or not but to me it has always sounded like saying that ashes are better for cooking than charcoal.

Ashes have already "reacted" and are spent. Patina sounds like similar circumstances. Now I have measured the pH of low wines and IIRC they tend to be acidic so maybe a little clean copper is exposed even with a patina, which would just mean that it is the clean copper doing the cleaning.

As for the new still taste, like I told someone in another thread who was going on about how horrible the taste was, I actually placed a piece of copper in my mouth, since they told me that if I did so I would see how horrible it was, and I replied that it didn't taste bad to me.

Opinions, what are we gonna do?
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Re: So, the answer was copper

Postby der wo » Tue Oct 11, 2016 8:48 am

Bagasso wrote:
der wo wrote:We have two contradicting opinions

Of the two contradicting opinions one is true. Clean copper reacts.

At least in acidic environment perhaps oxidized copper (patina) reacts more than clean copper because it gets solved more, so there are more copper ions in the mash.


I got a two new ideas about this quote:
"copper was found to reduce the level of this compound best when placed in the wash still condenser or spirit still pot."
- Why is the wash still condenser such effective? Perhaps because the slightly acidic low wines solved a bit copper or copper oxide and while the sample was brought to the lab or while a lag time before the spirit run it reacted with the sulfur?
- Why is the spirit still pot such effective? Perhaps because the spirit run needs much more time than the stripping run?
Those two points match with your observation, that the sulfur reduction needs much time.


Edit:
I just measured the pH of dirty grain low wines. Two different types of test strips. The expensive ones say 6, the cheap ones 5.8.
Sorry for my bad English!
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Re: So, the answer was copper

Postby SaltyStaves » Tue Oct 11, 2016 11:42 am

Bagasso wrote:
SaltyStaves wrote:You need a patina to bind sulfur components. Otherwise it behaves exactly like SS.

Listening to advice like this for years has gotten me nowhere. My coil has had years to build a patina and I don't do anything other than wash out with plain old water between runs. It has a patina and it has never been enough.


I've seen a build up occur with my own still which leaves the copper smelling like very salty cheese. It eventually gets a texture on it too. At this point, it needs a clean with a cloth and some fores to remove the funk (but also leaves the patina in tact. The first time I just let it go, that funkiness started carrying over into the distillate. I think rinsing with water is important, but it doesn't seem to keep things from eventually building up.
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