Question for Metallurgists - Starsan and plate chiller

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foles

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I have a very strange problem. Whenever starsan makes contact with either of my plate chillers (one a therminator), it gives off a horrible odour. Its almost as if it is reacting with the copper inside the chiller. When tap water or wort goes through the chiller, it doesnt seem to impart this odour.

On the rare occasion I have cleaned the chillers with caustic. Could this have destabilised something?

I'm worried non-biological (metallic) contaminants are getting into my beer. It isnt turning out great because the final beer PH consistently gets driven below 4 despite a proper mash and postboil ph (~5.5 at 25C). And there are no signs of infection.
 
star san is a mixture of acids... the caustic cleaner you used is basic. Mix the two and you will get a reaction that could be responsible for the smell...

Given that plate chillers are known to hang onto things - its a distinct possibility!

If you mixed your star san right, you should have no issues with it dissolving any metals. However, the caustic solution (whatever it was) could have done some surface damage.

If it was me, I would run a bunch of baking soda thru it (its an amphoteric compound meaning it can neutralize acids and bases) to clean it out and try the star san again after a heavy rinse with hot water.
 
I bake my chiller before every brew. I'm currently mashing in - doing a no-chill brew to see if I can pinpoint the chiller. I will give the baking soda method a try, thanks TRG
 
Maybe some sulfide is precipitating on your copper as copper sulfide, and the acid comes along and knocks it off. If this is the case you'll get a rotten egg smell. Sulfide can come from your water or from gunk that is left in the chiller.

Beer pH does drop from wort pH so that shouldn't be a problem.
 
Lennie said:
Maybe some sulfide is precipitating on your copper as copper sulfide, and the acid comes along and knocks it off. If this is the case you'll get a rotten egg smell. Sulfide can come from your water or from gunk that is left in the chiller.

Beer pH does drop from wort pH so that shouldn't be a problem.

Yeah ph drops but should be between about 4.1 and 4.5. I'm getting 3.8-3.9 and I think the chiller may have something to do with this abnormally large ph drop.
 
foles - I have nearly the same question in another thread. I too am wondering if StarSan in my plate chiller is causing a slight metallic/tannic taste in my beers.

I am usind a 30 plate Duda Diesel chiller sold by Keg Cowboy.

My Starsan mix is crystal clear in distilled water; however, once it cycles through the plate chiller, it comes out cloudy. Not dirty, but cloudy as if something were altering the solution.

It was suggested to me, by a commercial brewer who tasted my beers, that if the StarSan solution was not mixed properly, say a bit more concentrated than it should, it could be removing the pacification from the stainless inside. He suggested leaving the plate chiller to dry to allow the pacification to form again. This however defeats the purpose of sanitizing it ...

My thread is here: https://www.homebrewtalk.com/f14/metallic-tannic-taste-starsan-plate-chiller-294875/
 
I really doubt Star San is going to remove the passivation layer from a chiller, people leave kegs filled with it for rather long periods (like weeks or more) without doing any apparent damage...

Cheers!
 
Its definitely removing something in my chillers. Clean starsan in....... horrible metallic smelling starsan out. Thinking back this happened on first use before it got a caustic wash. Its got me completely baffled. My starsan PH is about 2.35, with filtered tap water. My tap water is unusually high in sodium (125ppm) and chloride (200ppm), but other minerals relatively low. Not sure if this will have an effect.
 
foles - I have nearly the same question in another thread. I too am wondering if StarSan in my plate chiller is causing a slight metallic/tannic taste in my beers.

I am usind a 30 plate Duda Diesel chiller sold by Keg Cowboy.

My Starsan mix is crystal clear in distilled water; however, once it cycles through the plate chiller, it comes out cloudy. Not dirty, but cloudy as if something were altering the solution.

It was suggested to me, by a commercial brewer who tasted my beers, that if the StarSan solution was not mixed properly, say a bit more concentrated than it should, it could be removing the pacification from the stainless inside. He suggested leaving the plate chiller to dry to allow the pacification to form again. This however defeats the purpose of sanitizing it ...

My thread is here: https://www.homebrewtalk.com/f14/metallic-tannic-taste-starsan-plate-chiller-294875/

Going in clear and coming out cloudy is a sign of PH change. I bet you have something inside the chiller that's buffering the Starsan and it's not the SS pacification. Test the PH of what's coming out and you will know.
 
thargrav - smart thinking, I will do it today. My LBHS is not open today - where can I find strips? Something Walmart would cary?

What could/would change the PH? I will test my process by leaving StarSan in the chiller for 30 minutes, then test, then again with a good water flush to see what's happening.
 
Something left inside the chiller.

The issues you guys are having is exactly why I don't like plate chillers.There are too many sharp turns inside waiting to grab onto pieces of hops, then once something gets lodged inside smaller particles pack in behind it.

I did try one for a while. My solution was to back flush the chiller after every use. And I did flush stuff out. This is why I stopped using mine.
 
Just my $0.02, I wouldn't leave StarSan (50% phosphoric acid) in a large concentration in contact with any metal for longer than 5 minutes or so. If you are, I would use an even more dilute concentration that the recommended 1oz per 5 gal on the bottle...plastic is a different story.

Can't you run a more dilute concentration through multiple times with a counterflow or plate chiller? I have IC so have no idea.

As a chemist(spending a considerable amount of time as a glorified dishwasher) I use the mantra less is more. If you use a high concentration, that excess will just be harder to wash off. I always rinse tricky things such as siphons, chillers, etc, right after use to make sure nothing gets too dirty to where a dilute solution won't do the job.
 
I switched to a immersion chiller that I wound myself.

When I used the plate chiller I would gravity feed from the pot through the chiller & into the brewpot. Now I drop in the chiller about 5 minutes before the end of the boil and I turn on the cold water faucet as soon as I turn off the heat. Or if I'm lazy I carry the brew pot over to a 2 comparment SS sink and I run cold water into the sink compartment, letting the hot water spill over into the other compartment. But I'm a 5 gallon brewer and I have options that 10 gallon brewers don't have because I don't have to deal with the weight.

If I decide to buy another counterflow chiller it will be one of these.
Chillzilla : Northern Brewer
 
UPDATE: I've established the ph / chiller odor thing isnt the source of my beer's low ph. I did a no-chill batch (i.e. using cube). 24 hours later when I pitched the yeast, the wort PH was unchanged 5.45 @ 25C. 48 hours into the ferment (at high krausen), a pulled a sample from the fermenter. PH was 3.98 and still at 1030. Unbelievable! Yet another undrinkable batch despite my best efforts. No sign of infection or sourness, just low ph and lack of of or malt flavour resulting from it.

Whats funny is I left a cup full or wort to ferment from wild yeast in the air of my garage. That has attentuated a little, and PH was down to 4.8 after 24 hours, and 4.6 after 48 hours.
 
And......this thread is why I'm sticking with my little 'ol IC. That and the fact that our 55F well water produces pretty short chill times. I'm pretty sure if I were brewing batches ≥10 gal., this philosophy would change. But for 5 gallons I just don't need a counterflow or plate chiller......
 
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