copper vs stainless steel

Hey folks: I know copper has much better thermal conductivity than stainless steel. In fact SS is (correct me if I am wrong) considered an insulator. This is why coffee mugs are made of SS, stay hot while not burning your hands. SO why is SS recommended for jockey boxes. In fact why is SS used in any of the cooling systems of brewing. I can see it's benefits for brew pots(durability and eveness), maintaining temperature in lines but not a good choice when temperature needs to be raised or lowered. Am I right here??
Thanks Charlie
PS why can't beer flow through copper lines in a Jockey box, or can it? I was told it was better not to.

They make coffee cups out of stainless because they look really cool. They're double-wall for insulative reasons.

Copper is a better heat conductor but it doesn't hold up well to prolonged contact with acidic liquids like beer. That's why we compromise by using stainless for a jockey box. You just have to run a longer coil to make sure each consecutive pour is cold.

SS is NOT an insulator. It does have much lower thermal conductivity than copper - about 26 times lower - but it still definitely conducts heat. The reason SS coffee mugs don't burn your hand is that they're made with two layers, separated by air or vacuum - it has nothing to do with how conductive the SS is.

SS is used for storing and dispensing beer because it doesn't corrode or oxidize. Copper is fine for short-term use like wort chilling after the boil, but if you left beer in a copper line for several days I bet it would start to oxidize and turn nasty.

So a stainless steel wort chiller is no bad thing? It's my next piece of equipment, a chiller, I'm not happy with my cooling procedure even for partial boils, taking way too long to get to pitching temp!

cd2448 said:

So a stainless steel wort chiller is no bad thing? It's my next piece of equipment, a chiller, I'm not happy with my cooling procedure even for partial boils, taking way too long to get to pitching temp!

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Hey, if you want something with great thermal conductivity, go with aluminum for your chiller. I be you can get an all aluminum car radiator and pump ice water through it to chill the wort in no time.

cd2448 said:

So a stainless steel wort chiller is no bad thing? It's my next piece of equipment, a chiller, I'm not happy with my cooling procedure even for partial boils, taking way too long to get to pitching temp!

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Yes, it most likely WOULD be a bad thing, provided you are talking about an immersion or counterflow chiller... As I just mentioned, it has a thermal conductivity 26 times lower than copper, so if you made a wort chiller out of SS it would take WAY longer to cool your wort than if you made it out of copper, like most of them are - therefore it would most likely be hardly worth using unless it had gigantic surface area. And copper is cheaper. The only chillers that I know of that are made of SS are things like plate chillers, which are a very different design - they have a lot of surface area, use very thin SS plates (thinner than you could feasibly accomplish with an IC or CFC) and have design features that maximize turbulence.

You can get away with using copper for a wort chiller because, as I said, it will only be exposed to the wort for less than an hour.

I believe the only metal that out performs copper is silver and I don't think that would be very cost effective....not to mention aluminum car radiators are are sealed with lead, at least that is how they did it on "How It's Made"...LOL

Now I want a silver wort chiller. Talk about some $eriou$ brewing bling that would be

been using a copper coil in my jockey box for years....no probs

thanks for clarifying this. there are a few stainless steel chillers up on ebay - not much cheaper than the copper in fairness so might as well get the better performer.

Since the heat flow is through a very thin wall, using stainless for a wort chiller will have zero impact on the cooling times.

SS is used in jockey boxes and almost all professional brewing systems because you can use cleaning methods that would destroy copper. And it is much stronger.

david_42 said:

Since the heat flow is through a very thin wall, using stainless for a wort chiller will have zero impact on the cooling times.

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Provided it is indeed extremely thin, then I suppose that the effect would be minimal. I have not seen a SS wort chiller in person so I don't know how thick the tubing walls are. I hadn't stopped to think that the stainless tubing would likely have very thin walls since the material is much stronger to begin with.

Once, after I shut off my burner, I sprayed down the outside of my keggle with water so it wouldn't burn my wooden dolly when I placed the keg on there to wheel it inside for chilling. Even the side walls near the bottom, which are in direct contact with the wort on the inside, took a while to cool down to wort temp - it took quite a few sprays before it cooled enough to not instantly steam off the water, which surprised me as I would have expected it to reach equilibrium very quickly - the SS sheet metal that kegs are made of really isn't all that thick. Just goes to show how bad a heat conductor SS is.

Coils that are stainless are for jockey-boxes, see kegman.com. Last long, commercial set-up type thing. HB-ers jockey-boxes will just have a copper coil-'cause that's all it takes...you pay for what you get but what do you really need? Nobody sees a jockey-box coil, so bling is a futile effort there....

Chiller coils of copper are for wort-they're cheaper and not apt to be put to full time use.

http://kegman.net/coldbox.htm

http://www.kegman.net/ss_coils.htm

http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html

Silver FTW, but not by much. And while we're at it, gold isn't all that bad either.

oh and car radiators=lead and antifreeze.

Just to follow up on this thread....

david_42 said:

Since the heat flow is through a very thin wall, using stainless for a wort chiller will have zero impact on the cooling times.

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Well, I'll soon find out, as I just bought one of those eBay stainless chillers. I didn't trust my second-hand copper chiller, with it's submerged compression fittings and haphazard zip-tied construction. Plus, I hated how it always came out of the boil cleaner than it went in! I'll probably use it as a pre-chiller once the warm weather returns.

The stainless one is nicely built. It's very light, I'm guessing the tubing is quite thin.

z987k said:

http://www.engineeringtoolbox.com/thermal-conductivity-d_429.html

Silver FTW, but not by much. And while we're at it, gold isn't all that bad either.

oh and car radiators=lead and antifreeze.

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I didn't see Tungsten or Titanium on that list! Now those would be durable wort chillers!

If anybody is still wondering if a stainless wort chiller can work well, wonder no more. I've used mine three times now, and it works GREAT. Certainly as well as my funky old copper one.

BlindLemonLars said:

If anybody is still wondering if a stainless wort chiller can work well, wonder no more. I've used mine three times now, and it works GREAT. Certainly as well as my funky old copper one.

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Blind-

That is exactly what I was looking for: an UPDATE!! (bbahahah)

Glad to hear it works good, cause I really cringe when I see the cleaner copper coming out of the wort....... I feel like -years later- we will look back on it and say...."Man copper is really bad for us, and look at how we used to poison ourselves...Just look how much chemical comes off the copper with each boil!"

I'm go'n STAINLESS!!!

Donasay said:

Hey, if you want something with great thermal conductivity, go with aluminum for your chiller. I be you can get an all aluminum car radiator and pump ice water through it to chill the wort in no time.

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Nice and now we're promoting the use of car radiators? Copper is a much better thermal conductor than aluminum and if it's only in contact with an acidic solution for a short period of time, it's definitely the best material.

EvilTOJ said:

I didn't see Tungsten or Titanium on that list! Now those would be durable wort chillers!

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Hmmm, tungsten chiller for a plasma-based beer wort...I like that! Tungsten could easily stand up to the 5000F temps needed to produce this plasma.

My SS wort chiller works great. I built a dual 3/8 coil (fed by 1/2" into tees) and I could watch the temps drop when whirl-pooling. Copper by the lb is a better conductor than SS but the copper soft tube is much thicker than the SS tube of the same diameter. It's really a minor difference, unless your coil is really short.
The copper ones come out cleaner because of the acidity of the wort, which is fine pre fermentation, the yeast eat the copper.
Jockey boxes are SS because the carbonated finished beer will pull copper from the coil, as well as the chemical resistance bobby mentioned.

I cooled my wort in a stainless steel sink with 99 cents of ice and it was at 78 in about 20 minutes. Color me stupid but does it really matter about the metal. I like the ease of cleaning with stainless. BTW, my beer is better than your beer.

clarkster said:

I cooled my wort in a stainless steel sink with 99 cents of ice and it was at 78 in about 20 minutes. Color me stupid but does it really matter about the metal. I like the ease of cleaning with stainless. BTW, my beer is better than your beer.

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How big was your boil kettle? And color me stupid, but I somehow doubt any of your statements.

fc36 said:

How big was your boil kettle?

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Around 72 ounces my guess.

40 quart, 5 gal batch. Sat the kettle in a sink full of ice and water and stirred constantly. 20 min. But I still want a SS wort chiller.

Nothing wrong with copper, it's been used in brewing for centuries.

http://www.brewingtechniques.com/library/backissues/issue4.5/miller.html

Ray

clarkster said:

40 quart, 5 gal batch. Sat the kettle in a sink full of ice and water and stirred constantly. 20 min. But I still want a SS wort chiller.

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Copper is a much more efficient heat conductor and it's very easy to maintain as well, not to mention much easier to solder if you decide to save a little $$$ and make it yourself. If you're still cooling in your sink, just do yourself a favor and don't buy the SS unless you've got the $$$ lying around. Also, assuming from the way you word your posts, you don't have many brews under your belt and you should just stick to cheap sh*t for now.

I don't have much experience with this, but from the little shopping if done, SS chillers are slightly cheaper at the moment. The loss in thermal conductivity vs copper is mostly compensated for by the thinner walls on the SS tubing. When you add the durability and easy maintenance of SS, plus that the chiller won't change colors on you, I am leaning towards SS as my first chiller. I know there's nothing wrong with copper, as previously stated copper has been used in brewing forever. I just don't like the idea of copper coming off into the wort. Plus SS would match my brew kettle. (Like that matters) Is my thinking skewed on this, or does this really come down to personnal preference? (On a 5 gal or less batch, that is)

armytech8098 said:

I don't have much experience with this, but from the little shopping if done, SS chillers are slightly cheaper at the moment. The loss in thermal conductivity vs copper is mostly compensated for by the thinner walls on the SS tubing. When you add the durability and easy maintenance of SS, plus that the chiller won't change colors on you, I am leaning towards SS as my first chiller. I know there's nothing wrong with copper, as previously stated copper has been used in brewing forever. I just don't like the idea of copper coming off into the wort. Plus SS would match my brew kettle. (Like that matters) Is my thinking skewed on this, or does this really come down to personnal preference? (On a 5 gal or less batch, that is)

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It's your dime and you should spend it in the way it makes you feel most comfortable.
Not sure where in TX you are but if you brew in the summer you will most likely be investing in a pre-chiller at some point. If you don't know what that is, it's another immersion chiller placed in a bucket of ice water to lower warm tap water temps. It's placed in series before the wort chiller. Copper would be a good choice for that.

armytech8098 said:

I don't have much experience with this, but from the little shopping if done, SS chillers are slightly cheaper at the moment. The loss in thermal conductivity vs copper is mostly compensated for by the thinner walls on the SS tubing. When you add the durability and easy maintenance of SS, plus that the chiller won't change colors on you, I am leaning towards SS as my first chiller. I know there's nothing wrong with copper, as previously stated copper has been used in brewing forever. I just don't like the idea of copper coming off into the wort. Plus SS would match my brew kettle. (Like that matters) Is my thinking skewed on this, or does this really come down to personnal preference? (On a 5 gal or less batch, that is)

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There is also the issue of copper actually acting as a nutrient for yeast during it's ramp up to full-blown fermentation. Not to worry though, just toss a few pre-1983 pennies or a short piece of copper tubing in with your boil and that oughtta take care of that.

Stainless vs. copper tubing is going to have virtually no effect on time to cool. The metal is not cooling the wort, it is the water running through the coils that cools the metal that cools the wort. While copper does have a much better heat transfer coefficient, even with needing to be a little thicker than stainless tubing for strength, in this application the temperate difference between the two metals with the water cooling is going to be very small and copper is only going to be seconds, if not less in cooling time. The true key to how fast you will cool using a wort cooler is the water temperature from your tap and how fast the water flows through the wort cooler moving heat away. The difference in these two metal materials is only going to have a minor effect. It like driving down the street 2 mph faster you will only save a few seconds.

The advantage of the stainless steel is that it is easier to clean prior to use and will not react with the wort. I have no idea if the minor reaction of the copper in the wort causes any negative consequence, it very well may not.

Now for those who think cooling small batches, 5 gal or less, in a stainless steel pot with a wort cooler is a lot faster than using an ice bath, this is just not the case. First the math will show the part of a 20 Qt. pot submerged in a 12” ice bath will have approximately a 40% larger cooling surface area than the coils of a 50' 1/2" wort cooler. You don’t get the same effectiveness as a wort cooler since you don’t have constant moving water that keeps moving heat away from the metal. So you have to take advantage of the larger surface area, slow self-agitation, and cooler ice water to make up some of the difference. You also have to have good control over doing water exchanges. What I have found works well for me is to start with an ice bath. Then after the ice melts I drain and refill using reusable ice blocks instead of ice. I consistently can cool in 20 minutes or less. I also have a stainless steel sink which helps dissipate heat but the sink also helps when using a wort cooler for pots that fit. For me the quicker set up time to use the sink only, lower risk of contamination, and less cleanup needed makes it worth the extra effort in controlling the ice bath and taking a couple extra minutes to cool. Anyway my 2 cents.

I brewed two batches without variation in temp or volume between the two. I used my copper immersion chiller in one, my friend's stainless steel chiller in the other to test the difference. Chilling 5.5 gallons after the boil took 1 minute and 32 seconds longer with the stainless steel chiller to get down to the exact same temp immediately after the boil.