Copper in HLT causing nasty flavours

[TheWiggman]

Refer to my other thread about my 3V build on the dramas I've had. Basically I've made 5 brews and tipped 3 out due to mainly melted sealant hiding in the sight glass of the boiler.

In the process of making 100% sure I've cleared anything that might ruin a brew I've found that my HLT water - used as a RIMS then later for the sparge - tastes... well, terrible.

I've boiled water in the kettle and mash tun for 15 min and both taste as they came out of the tap.
Water out of the HLT tastes metallic, which I'm blaming on the copper 1/2" tube at this stage.

See below for an inside shot of my HLT with RIMS coil. EVERYTHING is stainless except for the silicone seals and the copper tube -

This is the cleaning process before coming to this conclusion:

• I've left it sitting with a bleach solution overnight
• Washed by hand with dish washing liquid
• Rinsed
• Boiled
• Rinsed again
• Boiled
• Rinsed
• Boiled with 30ml vinegar to 15l water
• Rinsed
• Boiled again

Following the last boil I sampled some water out of it and left it in the fridge to cool. After tasting it an hour or two later, it tasted that strongly of copper/metal that I struggled to swallow it. No nasty aftertaste though.

I don't get it. I've seen a lot of other setups like mine and if it was such an issue people wouldn't do it. My first two brews were sparged with this water and some hot tap water, and no remarks about smells or off flavours yet. When I rigourously cleaned the systems to get rid of the plastic taste I ran the pump through the copper tube. I sampled the water later, and there were zero off flavours. This was at both boiling and >80°C.

Can anyone suggest anything? For now I'm going to retire the HLT as a HERMS and boil water on the stove in a few pots and pans to batch sparge. I'm not risking throwing another brew out.

 

[Yob]

What sealant? You have a sight tube on the kettle? Most don't.

To clean the inside (and outside) of the copper, run starsan through it for an hour in one direction and then an hour in the other (fill that keg with it too) then do a run through the system with you water, taste before during and after (fill 3 bottles and label)

 

[TheWiggman]

What sealant? You have a sight tube on the kettle? Most don't.

To clean the inside (and outside) of the copper, run starsan through it for an hour in one direction and then an hour in the other (fill that keg with it too) then do a run through the system with you water, taste before during and after (fill 3 bottles and label)

Did have a sight tube on the kettle. It never sealed properly so I bought a supposedly boil-tolerant sealant to stop the leak during the boil. That basically ruined my life. Read http://aussiehomebrewer.com/topic/76055-all-grain-3v-electric-system/page-2 for details.

The inside doesn't seem to be imparting any flavours, only the outside. I was wondering whether the 3m copper tubes at Bunnings may have a different surface finish on the outside to the inside.
I also don't have any Star San - I take it this is one of those must-own products. If I get some of that is PBW worth having as well? These seem to be the cleaning solutions of choice on this forum.

 

[Yob]

Citric acid?

 

[np1962]

StarSan is not a cleaner.
PBW is not a sanitiser.
Copper should not be a problem in your HLT.
As Yob has suggested try an acid solution to clean. Then PBW before a thorough rinse.

 

[Yob]

Starsan will bring copper back to like new though..

You can make an almost PBW mixing sodium percarbonate and sodium metasillicate if you can get your hands on some of that..

Or just jump for the good gear and never look back

 

[QldKev]

What's that big lump of goo in the bottom left hand corner of that vessel?
What has happened to the heating element?
Is that top stainless compression fitting rusting?

Why don't you remove the copper coil and try the water taste test on it again. Then you will know if it's the coil or something else.

 

[boonchu]

It does look like the copper is oxidising in places ( the green spots? )
is it worth swapping it out for a new piece or even up grade to s s?

 

[TheWiggman]

What's that big lump of goo in the bottom left hand corner of that vessel?
What has happened to the heating element?
Is that top stainless compression fitting rusting?

Why don't you remove the copper coil and try the water taste test on it again. Then you will know if it's the coil or something else.


Big lump of goo is actually water residue. I inverted the keg to empty the water before taking the pic.
Heating element (Keg King) earthed out and is on its way back to CB. Current element is from $14 Woolworths kettle.
That is a minor bit of rust of the fitting apparently, yes. Brand new fitting too.

If I were to remove the coil I'd be a bit stuck because I don't have any spare olives. Plus, it was an ordeal putting it in so will be an ordeal removing it. Valid point though and worth doing.

I figure in the short term I'll batch sparge using the boiler as the HLT and put the wort into a fermenter. So:
Finish mash cycle.
Rig RIMS up to boiler to get x litres of water to 78°C (it's my only thermometer)
Drain mash to fermenter.
Once at temp, fill mash tun up with sparge water from boiler.
Transfer mash liquor to boiler.
Wait 20, sparge to boiler to got pre-boil gravity.

It's workable.
Today I'll look for some citric acid and give that a go. If no good, once I get hold of some SS olives I'll consider dismantling the HLT.

 

[TheWiggman]

It does look like the copper is oxidising in places ( the green spots? )
is it worth swapping it out for a new piece or even up grade to s s?


Yeah I'm wary of the green spots. Not being a chemist I don't know how to address this nor whether it's indicative of the rubbish flavours I'm getting. I can clean them off with a rag but they return.
WORTH upgrading to stainless? If you ask my wife none of it was worth doing at all! If I was rolling in dough it would be a given.

 

[GuyQLD]

You've got serious oxidation in there, probably because of bleach. Bleach will strip the normal "dull" oxidised protective layer off the copper, and then you get the tarnished horrible stuff. Stick to PBW if there's copper around. You'll need to get rid of the green/black mess by scrubbing back to shiny copper - then I think running some hot water through it should be enough to start getting it back to usable. Someone better with metal work that I will be able to give you the details on that one.

 

[Ducatiboy stu]

From How To Brew

http://www.howtobrew.com/section1/chapter2-2-2.html


The best sanitizer for counterflow wort chillers is Star San'. It is acidic and can be used to clean copper as well as sanitize. Star San can be left in the chiller overnight to soak-clean the inside.
Cleaning and sanitizing copper with bleach solutions is not recommended. The chlorine and hypochlorites in bleach cause oxidation and blackening of copper and brass. If the oxides come in contact with the mildly acidic wort, the oxides will quickly dissolve, possibly exposing yeast to unhealthy levels of copper during fermentation.

 

[TheWiggman]

Well I scrubbed away as best I could and here's the water that came out of it -



Smelt exactly like the water that's been coming out of it. Currently recirculating cold water with the juice of 1 lemon. Will rinse, scrub, rinse then return to boil, hopefully that will be the end of it.
No more bleach near copper for me. In fact, no more bleach near the metals.

I'll have to buy some PBS and Star San after next pay day. Merry Christmas to me.

Cheers for the help folks.

 

[Smashin]

Worth noting that copper has been and still is in many brew houses a standard material of construction. When tooheys built their last major plant upgrade it was all stainless and the brew lost something. Now the have filled sections of the pipework with copper pipes which they replace every few years.

So copper does get dissolved into the beer and can be flavor positive.

Sent from my GT-I9505 using Tapatalk

 

[TheWiggman]

Cheers Smashin, maybe there is hope after all.

I've cleaned it up and am happy to say that there is almost no detectable taste in there. I'm doing a dry (?) run as per Yob's advice and have found the mash carries a bit of a chlorine taste no doubt from the bleach, and the HLT still has a very minor copper hint about it. If it was tap water though you'd drink it. Once finished I'm going to leave the HLT full with fresh water to prevent the copper oxidising.

Next weekend I may actually make a drinkable brew. Tragically though, when having a quiet glass in the shed I'm maybe one or two pours away from an empty keg. This is serious business especially considering Christmas is around the corner.

 

[TheWiggman]

So copper does get dissolved into the beer and can be flavor positive.

This must be a technique most major brewers use to make light beer.

 

[Yob]

1 lemon will not be enough, I seriously wouldn't be using it till you can get some starsan through it..

Every so often I do all my copper in starsan.. Bloody amazing stuff.

 

[manticle]

Household white vinegar will do it (clean oxides off copper) although starsan is my go to sanitiser and well worth having.

Boiling hot water and/or sodium metabisulphite solution will remove residual chlorine. Caution with sodium met, especially if asthmatic.

 

[TheWiggman]

Thanks all. Hit it with some metabisulfite (Coopers stopped making this in 2005 apparently - I still have some) and you're not wrong about the smell. Strong stuff and confirmed I'm not asthmatic. I rinsed the mash tun with 2l of boiling water to 50g of sodium met and the difference in odour is obvious. I then tipped this into the boiler and gave it a good rinse to cleanse all the bleach woes. I did a hell of a lot of rinsing afterwards so I'm hoping any hint of bleach/chlorine is gone.
I've already done the vinegar thing but to no avail.

Unfortunately Yob I don't have a home brew store nearby and so I'll batch sparge from the boiler for the time being. I'm not too concerned about the internals of the copper, there is no off flavour in the mash. Plus for any rinsing I might do it gets >15l/min of liquid running through it so it gets a lot of work. It also gets acidic wort pumping for hours on end so I'm pretty confident it's ok. I've got a Craft Brewer order due for shipment tomorrow so I'll try to add this to the order before it hits the mail.