FAQ: Aluminum Pots for Boil Kettles?

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FlyGuy

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The 'aluminum vs. stainless steel' (SS) pot debate pops up frequently, and given that we tend to see lots of new homebrewers enter the hobby shortly after Christmas, perhaps it is timely to post an FAQ on the subject.

Q: Is an aluminum pot OK for a boiling kettle in homebrewing? My LHBS only recommens using stainless steel.


A: Both aluminum and SS pots are excellent in homebrewing, and each has its own advantages and disadvantages, so it is purely a personal preference. Here are some considerations:


Aluminum Pots:
Pros:
- considerably less expensive than SS
- much better at conducting heat than SS, which means faster boils, faster cooling, and less chance of scorching
- not as heavy to lift as SS

Cons:
- oxidizes easily, meaning that oxygen-based cleaners (e.g., Oxyclean, One-step) cannot be used (Note: caustic or other similar clean-in-place solutions can definitely not be used, which is why the brewing industry generally does not use aluminum.)
- passive oxide layer must be built up before brewing (**see note below) with a new aluminum kettle, although it is very easy to maintain

Stainless Steel Pots:
Pros:
- can be cleaned by oxygenated/CIP cleaners without damaging the pot
- passive oxide layer that protects the pot is not as easy to remove as aluminum
- they are really shiny and look cool!

Cons:
- expensive
- not nearly as good at conducting heat as aluminum

Myths About Aluminum Pots:
- Aluminum pots will cause Alzheimer's disease. FALSE. This myth was debunked years ago by the medical research community, and the US National Institutes of Health and Health Canada have long since ruled out a connection between Alzheimer’s disease and aluminum cookware. If you don’t believe me, see the following:
http://www.alzheimers.org.uk/site/scripts/documents_info.php?documentID=99
http://alz.org/alzheimers_disease_myths_about_alzheimers.asp
http://www.ehso.com/ehshome/alzheimers.htm

- Boiling your wort in an aluminum pot will cause off-flavours in your beer. FALSE. Simply boiling a batch of wort will not remove enough metal from your aluminum pot to get into your beer and cause metallic off flavours, particularly if you build up a passive oxide layer inside the pot first. For new pots, this is easily achieved by either boiling the pot full of water for 30 mins to one hour, or by putting it in your oven for 10 mins at 350 F.

- Aluminum pots have very thin walls, and are not suitable for a boil kettle, particularly if you want to install a ball valve. FALSE. Thin- and thick-walled pots are made from both aluminum and stainless steel. The material they are made from is much less relevant that the thickness of the pot.

- Aluminum pots will react with very acidic materials, and wort is acidic. NOT REALLY. Wort isn’t acidic enough to cause a problem with an aluminum pot. In fact, both SS and aluminum are quite resistant to acidic materials, and you need to be concerned more about highly alkaline (i.e. basic or high pH) materials with your pots.

- Aluminum pots are simply not as durable as SS pots, so why bother, plus they will scratch easily and harbor bacteria. PERHAPS, BUT... Both aluminum and SS are durable enough for homebrewing if you are willing to invest just a small amount of care for your equipment. You simply aren’t going to wear out an aluminum pot in your brewing lifetime, so this is a moot argument. Furthermore, scratches aren’t really a concern with a kettle since the heat of the boil is going to sanitize it anyways.

The Bottom Line:

You can’t go wrong with a quality stainless steel pot, and they are a tried-and-true solution for lots of homebrewers. Yet, aluminum is a viable alternative that is much less expensive than SS. In fact, you can generally purchase a larger and heavier aluminum pot compared to the equivalently priced SS pot. In homebrewing, I guarantee you will really appreciate having a larger pot that is heavy and conducts heat well, speeding our boiling and cooling times and reducing scorching. In my mind, this far outweighs the cosmetic appeal and somewhat higher durability of a SS pot.


I have probably missed a few important points, but would be happy to ammend this post to keep it thorough and accurate.
 

bradsul

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Great job FlyGuy! I've been meaning to dive through all the aluminum vs stainless threads to create a wiki article, now I just have one thread I need to look at. :D
 

abracadabra

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It seems to me that FlyGuy comes to the debate from a somewhat biased prespective judging by the argument made in favor of aluminum.

Another Con not mentioned against aluminum is that it dents and bends easily.

And the argument in favor of aluminum that it will reduce scorching vs Stainless Steel is simply not true with regard to boiling wort. An aluminum pan may be slightly less likely to scorch a steak or a pot of beans than a stainless steel pan. But boiling wort is another matter entirely as the wort (mostly water) moves inside the pot with the hotter portion moving up and the cooler portions moving down. I don't believe anyone can truthfully say that they have scorched their wort because they used a stainless steel boil pot.

Furthermore the argument for aluminum that it will speed your heating and cooling time while technically true the difference is miniscule.

There's nothing wrong with using aluminum pots but let's keep the debate even handed.
 

bradsul

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abracadabra said:
I think that FlyGuy comes to the debate from a somewhat biased prespective judging by the argument made in favor of aluminum...
I think it appears biased because the question is 'Is an aluminum pot OK for a boiling kettle in homebrewing?' The question itself is about aluminum - stainless is used as the basis of comparison since everyone knows the properties that stainless possesses.
 

5 Is Not Enough

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abracadabra said:
Another Con not mentioned against aluminum is that it dents and bends easily.
The same thickness pot would bend/dent much easier w/ aluminum vs ss, but in the time I spent shopping, I realized that they just don't make pots out of aluminum that are that thin. I couldn't bend my aluminum w/ all my weight, but my SS I could crumple if I wanted to.
 

RICLARK

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Just seems like that if an Aluminum pot can Boil 5 gallons of peanut oil and a big ass turkey than it can handle some wort, I just went out and bout a 34 qt Turkey Fryer last night.Thanks for these debates everyone they really help us newbies.
 

abracadabra

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5 Is Not Enough said:
The same thickness pot would bend/dent much easier w/ aluminum vs ss, but in the time I spent shopping, I realized that they just don't make pots out of aluminum that are that thin. I couldn't bend my aluminum w/ all my weight, but my SS I could crumple if I wanted to.
They don't make aluminum pots as thin as some stainless steel pots because they can't, it's too weak.

You and large group of your friends couldn't crumple my stainless steel pot.
 

abracadabra

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bradsul said:
I think it appears biased because the question is 'Is an aluminum pot OK for a boiling kettle in homebrewing?' The question itself is about aluminum - stainless is used as the basis of comparison since everyone knows the properties that stainless possesses.
I beg to differ. If everyone knows the properties of stainless then why bother with the post?

From my experience the reference to stainless steel scorching your wort is completely over blown.

I'm not trying to cast aspersions on FlyGuy as I'm sure his motives are purely altruistic, just trying point out what seemed obvious to me.
 

5 Is Not Enough

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I think the biggest point is the "is it dangerous?" aspect.

My LHBS still swears against using aluminum because 'it will cause off flavors and Alzheimer's". This is coming from a "professional", but I think FlyGuy did a great job w/ pointing out the facts.
 

Kevin Dean

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bradsul said:
Because the post is about the properties of aluminum with regards to brewing, not stainless.
I'm an aluminum user and damn proud. However, the thread here is entitled "Aluminum vs. Stainless Steel Pots for Boiling Kettles?" which implies it's about kettles - aluminum and SS respectively.

abracadabra said:
There's nothing wrong with using aluminum pots but let's keep the debate even handed.
While comparing thickness to thickness, SS is stronger but I don't think that's horribly relevant to the discussion since you can find pots in either SS or Al that, treated with respect, will last a lifetime.

The fact that a group of linebackers can jump on the walls of the thing are as irrelevant to it's suitability for brewing. I think you're being fair, but honestly nobody can be "unbiased" since everyone has different criteria. Stainless steel is easier to keep shiny too, but appearances aren't a factor that plays into my purchasing decisions frequently - that said for ME aluminum has the advantage. One doesn't need to be biased to give a price/point opinion.

/me isn't debating. /me wants to make sure all relevant info gets in the top post. :mug:
 

bradsul

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I've updated the wiki article. I didn't add the pros/cons for stainless since it has nothing to do with the question answered on the wiki page (perhaps another companion page 'is stainless safe for brewing?' should be created? They can then cross-link.
 

abracadabra

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bradsul said:
Because the post is about the properties of aluminum with regards to brewing, not stainless.
I'm sorry Brad I just don't follow your logic here.

The title of the thread is "Alumimun vs Stainless Steel Pots for Boil Kettles" . While the question posed is somewhat different. The title is what is going to lead people to the thread.

Another Con not mentioned about aluminum is that in order to safely brew, the inside of aluminum pots should not have the dull gray aluminum oxide cleaned or scurbed off once it builds up inorder to reduce the amount of aluminum oxide ingested. Although he does mention it in a round about way.

Or the fact that the aluminum oxide can and does come off when the sides of the pot are hit by say an IC being swirled around in it. Whether or not you want to ingest that alumumin oxide is up to the individual.

If we are going to have a discussion I think we should strive to eliminate conjecture such as Stainless steel might scorch your wort or aluminum is much faster, when that is simply not the case.

Guy said he was willing to amend the post I'm simply pointing out things to make it look more like a true discussion of the facts and less like a commercial for Aluminum.
 

Kevin Dean

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bradsul said:
I wonder if the thread title should change to remove the 'vs' aspect and just answer the question 'is aluminum safe for brewing'.
I've never heard anyone ask "Is this kettle {thick,shiny} enough to brew with" so I actually think that question makes a ton of sense in terms of answering a VERY common question. At the same time, there's a lot of information about kettles in general on this thread.

That said, I don't really care. :p I've reference this thread where I state that I think these kind of threads are borderline useless.
 

bradsul

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The main problem stems from the fact that the thread title doesn't reflect the question that is actually answered in the OP ('Is an aluminum pot OK for a boiling kettle in homebrewing?'). Hence my suggestion that the thread title itself be changed. There is no need for a 'vs' thread as it's accepted that stainless is perfectly fine. The question is whether or not aluminum is.
 

abracadabra

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Even then the question is:

Q: Is an aluminum pot OK for a boiling kettle in homebrewing? My LHBS only recommen(d)s using stainless steel.

Making it an Aluminum vs Stainless Steel question because of the reference to the LHBS recommendation that follows.

And as Guy states if the FAQ is for noobies then I think assuming they are fimilar with the atributes of Stainless Steel is flawed.
 
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FlyGuy

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In response to the debate (re-)emerging above, yes – perhaps that wasn’t the most appropriate title. Can a mod please change it from “FAQ: Aluminum vs. Stainless Steel Pots for Boiling Kettles?” to simply “FAQ: Aluminum Pots for Boil Kettles?” in the forum index? Thanks very much.

Regarding the content, I don’t believe there are any factual errors. I purposefully did not cite references because I honestly didn’t think anyone would contest the credibility of these statements. Most of the information is drawn from John Palmer’s articles in BYO (especially the November 2007 issue) and his book “How to Brew”. John is one of America’s most respected homebrewing authorities, and a metallurgist by trade, so he is clearly a trusted authority on the topic.

Here is a direct quote from Appendix G Brewing Metallurgy of the most recent edition of Palmer’s “How to Brew” (page 309): “Aluminum is a good choice for brewpots and actively heated mash/lauter tuns. It has high heat conductivity, which helps prevent hot spots and scorching of the wort or mash, and is less expensive than stainless steel.” It is also clear from John’s articles that properly seasoned aluminum pots will not create metallic off-flavours in beer.

I have amended my post by removing the con that SS pots “may be more prone to scorching.” The statement may draw too much attention to this issue, and I certainly don’t want anyone to think that a SS pot will necessarily lead to scorching. Good pots shouldn’t, although it might also be mentioned that many of the most expensive SS pots actually have an aluminum clad bottom that is purposefully designed to conduct heat better and prevent hotspots in the pot.

To reiterate my original message, I am not advocating one type over the other. I actually have many pots, some of which are aluminum and some are SS. I use each in different circumstances and I am happy with them all. The point to my FAQ was to make it clear that BOTH are good choices, and to highlight the strengths and weaknesses of each pot so that people can make an informed decision if they are looking to purchase a pot.
 

3rd and Long

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Another consideration people may want to think about is you upgrade your systems you may consider using an Aluminum pot for HLT in a three teir system. I've been doing that for over a year now and it has worked out great. This way I get the advantages of aluminum for heating water for mashing and sparging, and the advantages of SS for my kettle.
 

RICLARK

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FlyGuy said:
- Boiling your wort in an aluminum pot will cause off-flavours in your beer. FALSE. Simply boiling a batch of wort will not remove enough metal from your aluminum pot to get into your beer and cause metallic off flavours, particularly if you build up a passive oxide layer inside the pot first. For new pots, this is easily achieved by either boiling the pot full of water for 30 mins to one hour, or by putting it in your oven for 10 mins at 350 F.



I got my new 34 Qt pot and I boiled water in it for 1 hour and it Turned the inside of the pot black, Is that what Im looking for?
 
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FlyGuy

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RICLARK said:
I got my new 34 Qt pot and I boiled water in it for 1 hour and it Turned the inside of the pot black, Is that what Im looking for?
Yep, that's the passive oxide layer. It will protect your pot and your wort. Don't scrub it off. Just gently wash it with a non-abrasive cloth or pad after each batch, and you are set.
 
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Do any of the brewers using aluminum kettles have couplings welded in them. I assume you would have to use an aluminum coupler and get the pot TIG welded. Is this correct, or can you weld SS to Aluminum? In the same vein does someone know if you can braze aluminum?

thanks
 

slnies

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I am sure in sum obscure text you could find a way to weld SS to Al, but in general the answer is no. Don't do it, because it is not pretty. I watched a newbie at our shop try something like that and it kind of exploded and ruined a good tungsten electrode. Good question though. S.
 

bluechip101

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I read several threads on this subject several months ago when I was shopping for pots. I was going to make a Keggle until I found this on Ebay for $35. It is a resturant grade 60qt Aluminum stock pot. I love it!

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bluechip101

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I just drilled a hole in it and used brass fittings bought at Lowe's to do the plumbing. You can buy the bulkhead valve kits for kettle conversion online and at Homebrew stores and they are expensive! I made my own for half that. You don't even need the Hi-Temp Silicon o-rings. I used just regular o-rings from the plumbing section and I have had no issues and no leaks. My burner is a rocket ship so that pot gets plenty of heat. My vote is for aluminum...cheap, easy to use, durable, and a lot easier to use than a keggle.:D

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cheezydemon

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With all of the aluminum foil used in cooking, and all of the aluminum cans used to hold beverages including beer, I am amazed that this is even an issue.

With the amount of aluminum used in packaging and everything else, the only thing that makes sense to me, is that altzheimers victims' bodies can't filter the aluminum out of food and dispose of it like the rest of us can.

So yes, if you have altzheimers, for God's sake don't brew in it. Also don't eat candy bars or frozen dinners, or anything else packaged in aluminum.
 

hammer one

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I just bought a turkey fryer at a Harris Teeter for 20.00 bucks , just for the burner but now I'm looking forward to a full boil. thanks for the great info.
 

Dextersmom

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FlyGuy said:
The 'aluminum vs. stainless steel' (SS) pot debate pops up frequently, and given that we tend to see lots of new homebrewers enter the hobby shortly after Christmas, perhaps it is timely to post an FAQ on the subject.

Q: Is an aluminum pot OK for a boiling kettle in homebrewing? My LHBS only recommens using stainless steel.


A: Both aluminum and SS pots are excellent in homebrewing, and each has its own advantages and disadvantages, so it is purely a personal preference. Here are some considerations:


Aluminum Pots:
Pros:
- considerably less expensive than SS
- much better at conducting heat than SS, which means faster boils, faster cooling, and less chance of scorching
- not as heavy to lift as SS

Cons:
- oxidizes easily, meaning that oxygen-based cleaners (e.g., Oxyclean, One-step) cannot be used (Note: caustic or other similar clean-in-place solutions can definitely not be used, which is why the brewing industry generally does not use aluminum.)
- passive oxide layer must be built up before brewing (**see note below) with a new aluminum kettle, although it is very easy to maintain

Stainless Steel Pots:
Pros:
- can be cleaned by oxygenated/CIP cleaners without damaging the pot
- passive oxide layer that protects the pot is not as easy to remove as aluminum
- they are really shiny and look cool!

Cons:
- expensive
- not nearly as good at conducting heat as aluminum

if its for boiling wort doesn't it not matter if you're going to use oxy-clean or one step. you're gooing to be boiling with it anyway which will kill most everything. and really if you needed to be 100% sure couldn't you use a bleach sani solution made from water and bleach?
 

Cheeto

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what about enamal coated pots ( like the ones used for camping)

I bought a 25qt at Wally-world for $21.87

will this cause me any troubles ???
 
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FlyGuy

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They work fine, as long as you don't chip them. If you do, they can leach metallic off-flavours into your beer. Despite having one, I don't know much about their thermal characteristics. Probably pretty similar to SS.
 

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Of course aluminum will bend/dent easier than SS; it is a softer metal. I have 2 10 gallon pots, one of each, and really don't see any advantage/disadvantage with either. In either pot, carrying 50 or so # or liquid and pot isn't a fun time, but you gotta do it. I had the aluminum much longer than the SS and everyone stated, 'You can't use aluminum, it will give a metallic taste to your beer'. I was skeptical when I first got it, but nothing of the sort. Besides, as everyone knows, aluminum is much cheaper. If you can get aluminum, go for it!
 

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How do you get the passive oxidation layer on the aluminum? I just bout a 30.00 turkey fryer that is aluminum and I have bolied some water in it to try out the wort chiller I made but I am clueless on how to make it have a passive layer.
 

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I think the thing to do is to fill it up with water, and then boil the water for like 30 minutes to an hour. This should give you a dark coating on the inside, which is what you want.
 
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FlyGuy

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Yes, that's what I have done and it works very well. If it will fit, you can also stick it in the oven at 350 F for about 10 - 20 mins until it darkens, but I don't like this method as much because the outside of your pot will oxidize too, and no longer be nice and shiny!
 

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I have heard that aluminum can retain flavors from cooking, then pass them on to your beer. So if i boil a pot of onions or cabbage I'll end up with oniony beer. Is this true? Should an aluminum brew pot be kept strictly for beer?
 
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