A perpetual debate among home brewers and on various discussion forums is the merits of aluminum vs stainless steel pots for brewing beer. This week we look at the pros and cons of each to help you make your own educated decision on your next beer brewing pot.
Aluminum Pot Pros and Cons
Aluminum pots are widely available and inexpensive because aluminum cookware is widely used for preparing foods. Inexpensive Turkey pots in the 36 quart range can be found at your local Walmart, particularly right after Thanksgiving at great prices. Aluminum pots cost considerably less than stainless steel – often half as much. Aluminum is a better conductor of heat than steel, so your pot will come to a boil faster and also cool down faster after you are done boiling.
The only major disadvantage of aluminum is that it will oxidize, so you can’t use oxygen-based or caustic cleaners such as Oxyclean. This is the major reason why professional brewing equipment is made of stainless steel and not aluminum – the stainless steel is easier to clean with caustic cleaning agents. Also, over time aluminum will get an oxide layer over it which can discolor the aluminum and give it a grey tone. This is not a cause for concern – the layer of aluminum oxide actually protects the pot, but it is not as pretty as stainless steel.
I feel it is important to address a number of myths about aluminum. First, aluminum pots are not linked to Alzheimer’s disease. A number of medical studies since the 1970’s have found zero link between Alzheimer’s and the use of aluminum. Keep in mind that every day you drink soda from aluminum cans (though most are lined) and eat food prepared in aluminum cookware – it is safe.
A second myth is that aluminum will react with acidic content of the wort and either add off flavors or eat away at your pot. This is also untrue – water has a pH of7.0, your wort has a pH of around 5.2, while spaghetti sauce can run as low as 4.6 and the most acidic diet sodas you drink run as low as 2.5. For comparison, battery acid has a pH of 1.0. Your wort is simply not acidic enough to react with your aluminum pot.
Stainless Steel
Stainless steel pots are the “Cadillac” of brewing pots, with designer pots running into the many hundreds of dollars in price. They are more expensive than comparable aluminum pots, but are a favorite of serious brewers. Stainless steel will remain shiny, as the passive oxide layer is not visible – so its easy to tell when your stainless pot is truly clean.
An advantage of stainless steel is that you can use oxygenated cleaners on it, which makes it a favorite with professional brewers who need to clean large vats. You should avoid long term exposure to bleach based cleaners as these can pit your stainless steel pots and vessels.
Stainless steel is stronger than the softer aluminum metal, so it is less prone to denting and scratching for a comparable wall thickness. However, you are unlikely to outlive a well made stainless or aluminum pot in either case. Stainless has a strongly bonded oxide layer, so it is less susceptible to attack by acids, though again the acidity of wort is not a concern for either metal.
The major disadvantage of stainless steel is that it does not conduct heat as well as aluminum, which means a longer time to reach boil and also longer cooling times after the boil.
Which to Choose?
If you select a well made heavy-duty pot, large enough for a full boils that is heavy and conducts heat well, you can’t go wrong with either stainless or aluminum. I look for a heavy pot with thick walls as it will conduct heat better and also hold up well to the occasional nicks and dings. An ideal pot has a diameter approximately equal to its height. A well made aluminum or stainless steel pot will likely last a lifetime.
If you are a brewer on a budget, you can’t ignore the large price advantage of aluminum – often it costs half as much for a comparable pot. Stainless steel has a “cool factor”, but it also has a price associated with being cool. Now I personally use stainless steel, but I’ve also been brewing for 25 years and started out using a cheap kitchen pot.
Do you have your own thoughts? Leave us a comment below. If you want to support us, you might want to consider a pot from Adventures in Homebrewing, a BeerSmith Supporter here. Thank you for reading this week’s BeerSmith Home Brewing Blog, and don’t hesitate to subscribe if you want more great brewing articles on a regular basis.
Get the best of both worlds. I have a 10 gallon SS pot that has a layer of aluminum sandwiched between SS on the bottom of the kettle.
I just ordered my second 15 gal aluminum pot. The walls are 3/16 thick, and all for $50 shipped. Can’t come close to that price with stainless. This is a hobby for me, so I have to stay within my hobby budget, so for me the choice for aluminum was a no brainer, and it works great.
Now I just need to think about adding ball valve to both so I can start doing some 10 gal batches.
Brad-
One minor point about aluminum cans is that they are internally lined, so no aluminum actually comes in contact with the beverage unless the liner gets damaged.
That being said, I use aluminum for my brew pot for the reasons you stated. A 32qt aluminum “tamale pot” was $18 at target… beat that! Boiling plain water in it one time put a good, strong oxide layer on it that will protect the pot.
Thanks – I made a correction to the article to note that the soda cans are lined. — Brad
Hi, Brad.
Another minor point… battery acid is around 30% sulfuric acid by mass (around 5M for us chemistry geeks), which has a pH around -1, making it about 3100 times more acidic than a 2.5 pH soft drink. You’re dead on about aluminum and acids though: aluminum surfaces form an oxide coating when exposed to air that makes it pretty much impervious to any acid you’re ever going to have around your kitchen! (You don’t keep undiluted hydrochloric acid around the house, right?)
Certain chemicals aren’t good around aluminum though because they can both remove this oxide coating and dissolve the aluminum underneath. The three biggies are: sodium hypochlorite (household bleach, but it’s very dilute), sodium percarbonate (most oxygen based cleaners), and especially sodium hydroxide (which is in lots of the caustic industrial cleaners you mentioned).
Thank you for the tips on the chemicals!
Thanks for the tips on using pots when brewing beers. This thing really helps.
So I just bought a fryer and used the 32q aluminum pot to make a batch of beer without doing the boil in to get the oxide layer on the pot, wort tasted fine when i sampled it, and all seemed alright… not doing the boil in i guess you call it, will that damage these pots? I plan on doing it before my next batch of beer, but i already do one.. hopefully i didn’t destroy this batch of beer, it’s fermenting now i guess i’ll find out in a few weeks when it goes to the keg….
Greg,
Its unlikely you did any damage – a fine layer of oxide forms over the aluminum even as it is sitting on the store shelf. It just becomes more visible and obvious with use. I would just enjoy the beer!
Brad
Interesting article. Home brewing brings back fond memories. My best friend’s brother used to do it in the ’80s… with mixed results.
Hi Brad,
I’m a professor of biology and my research is Alzheimer’s disease (AD). I would have to disagree with you on stating that Al is definitely not involved and completely safe. One of the problems we see in AD is neurofibrillary tangles. There is strong evidence that Al is playing a role in these tangles, at least some of the time. Further, it is unclear what else Al is doing. Like lead (Pb) Al is toxic to the young much more so than the old. So I’d probably recommend a pregnant woman try and avoid Al and also recommend parents avoid giving anything containing Al to young children or babies, just to be safe. But again, the precise nature of Al is still not clear. Mostly because no one was investigating it until recently. 5 years ago if someone had asked me about Al and AD or cancer I would have said I have no idea. But today there are a multitude of studies. According to one review article around 68% of peer reviewed studies they analyzed found a link between AD and Al. Therefore, I wouldn’t freak out from eating Al but I, personally, try to avoid it. Also, it is not an essential mineral. It doesn’t appear that our bodies need it or want it so why take the risk?
Lastly, this post only addresses the concern over AD and not cancer. As I’m not a cancer researcher I’m not going to try and say one thing or another on the subject. But it is worth noting that there may be a link between Al and cancer. (Just for clarification, I am not talking about breast cancer here.)
Sincerely,
Thomas
Thanks Thomas – that is counter to the information I have found, especially given the huge number of aluminum cooking pots on the market but thanks for the info!
Thomas, I have also read similar information before; however, this is a beer forum. 5 year olds and pregnant women are not drinking and probably not brewing beer, but if they are then that is a whole other discussion! lol.
I have a 40 quart Wearever Aluminum pot that I bought at a garage sale for $1 and have been brewing in for 13 years. talk about an awesome return on investment 🙂
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Will PBW hurt an aluminum pot? I’ve read the label and it only says not to use it on Teflon. I’m thinking of getting an aluminum boil kettle but use PBW for clean up and love it. Thanks.
Brian D,
PBW will definitely harm you’re aluminum pot, do not use! My idiotic self tried this one time and I may have left it in there for 20 or 30 minutes, when I came back I found that the inside of my pot looked like the moon with numerous craters and it pretty much ruined it. The next several hours were spent sanding them out, brushing and then boiling over and over to make sure all the aluminum excess was removed. Needless to say not a high point in my brewing career!
Brad, Besides the “cool” factor, 304 Stainless Steel is the standard for the food preparation industry. Look in the kitchen of your favorite restaurant – everything is SS, including countertops and walls. It’s easy to clean, impervious to most chemicals, quickly regrows its protective oxide layer when scratched, and will take a beating. Knives and forks and spoons are all stainless steel. Commercial beer kegs and homebrew Cornelius kegs are 304 stainless. Type 316 (more corrosion resistant) is used in the pharmaceutical industry, which is just really advanced cooking.
In the home kitchen, pots and pans are typically aluminum simply because of cost. But when you really burn something, you throw out the pot and buy a new one.
I think the real criterion is your intended purpose. If you’re doing extract brewing on the kitchen stove, a good aluminum pot is inexpensive and will do exactly what you want it to. When/if you advance to all-grain brewing or serious production, you’re probably going to want to add some fittings and valves – impractical with aluminum. That’s when it’s time to shell out the big bucks for something like a Blichmann Boilermaker.
Hello, I’m wanting to try open fermentation and it would be very expensive to do it with stainless. Would an aluminum pot work?
Thank you,
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@dave…why are fittings and valves impractical with aluminum pots? I find them to be more practical from the standpoint of installation.
IMO, stainless is a superior material. I wouldn’t ferment in an aluminum vessel as the both surface area in contact with the metal, time that the liquid is exposed and the pH of the liquid will affect the amount of “aluminum like flavor”. The things that makes stainless a superior material is its resistance to corrosion, easy of welding, lower heat transfer rate.
The reason that heat transfer rate is important is that if you heat a batch of beer on an iron element in a thin aluminum pot you will be able to see exactly where the element was touching pot as there will be a large amount of malt burned to the bottom. This will increase the amount of non-fermentable sugars in the beer (especially if you scrape the bottom 😉 thus more sweetness less alcohol. This can become a problem in high gravity batches.
As mentioned aluminum forms an oxide layer which is eroded during long periods of contact with low pH liquids. Similarly, I have boiled my copper chiller in a 1:20 vinegar to water solution for 1 hour and the copper comes out of the bath looking shiny and new. The oxides in aluminum can and will contribute to off flavors which will become noticeable over longer periods of time. This can be a problem if the beer is intended to be laid down for a longer period of time.
Finally, both metals have their drawbacks when it comes to welding or cutting but stainless is by far the more forgiving of the two. Since its hardness is higher it will scratch less and not as deep which means less microbes hiding in hard to reach places. This is important if you are using a ice bath to reduce your wort to fermenting temperatures.
My pot is 16.25 Gal., 304 stainless, NSF certified which I modified to fit a weld less ball valve and thermometer. My total cost is was 300 dollars even 6 years. The bottom of the pot is a 12 ply sandwich of copper and stainless which increases the heat transfer rate while keeping the distribution of heat even. I still have hot spots on the bottom but this problem is minimal. My total cost is was 300 dollars even 6 years ago. It is an investment and is worth it. For beers with high residual sweetness I have to boil for at least 1.5 hours. Try doing that with a cheap aluminum pot. Stainless isn’t a “Cadillac” it is a commercial grade product which is built to last.
My advice is to hold out for the better option. You may save money on aluminum and maybe you can make it work. But, if you wanted to make cheap beer why not just buy an ice beer? Brewing is minimizing the things that will make your beer bad, the brew kettle can ensure that your hot/cold break, hop extraction and sugar development happen how they are supposed to.
Cheers.
Just bought a 10 gal brew kettle to try BIAB. My other kettles are stainless steel. I usually use PBW or oxyclean. The posts above say not to use either. So what is recommended? Thank you
The PBW Tech Sheet says it is safe to use on aluminum:
http://www.midwestsupplies.com/media/downloads/311/PBW%20Tech%20Sheet.pdf
I’m looking to purchase a stainless pot for my dad for Christmas. He mentioned something about avoiding a brushed interior so the wort will not stick. Is this a rational concern? Do you have any recommendations on these type of things? I’ve been looking at various home brewing supply sites, and I am getting frustrated because I cannot tell if the items I’m viewing have a brushed interior.
great article you just saved me a easy 100$ and a large butt chewing.
Unfortunately your assertion that aluminum has proven to be safe is so far from being correct it is scary. Perhaps in 2010 when written there wasn’t so much info available, but there is less and less doubt now about the dangers of aluminum. It is very insidious, being everywhere, from tin foil (aluminum) to being in the air and washed into the water supply from rain. I suggest everyone who cooks in aluminum check this website:
http://articles.mercola.com/sites/articles/archive/2014/03/22/aluminum-toxicity-alzheimers.aspx
before being seduced by the cheap price and convenience.
Ive been using aluminium for about 3 yrs now and they are awesome. Yes no abrasive cleaners def. not caustic it will put off a flammable gas that can kill you. But for the price of 30 gallon stainless kettles witch range from 350-450 a piece depending on options. I paid 350 for 3 30 gallon aluminium kettles and haven’t looked back. And I brew alot being in northern in it is difficult to do all year round but possible. It is all up to you what you want to buy. I am on a budget like most home brewers soooo.
Aluminium oxide breaks down when in contact with liquids of pH<~4. This is at room temperature and normal atmospheric pressure. Brewing involves heat and pressure, 2 things which will allow aluminium oxide to break down (thus exposing the beer to aluminium) at a much higher pH (up to between 5 and 6). So your claim that a liquid of pH of 5.2 is safe could, in fact, be untrue depending on the temperature and pressure involved.
we are a special manufacturer in stainless steel brew kettle ,we can supply best quality ,best service .if you have any question about it ,pls feel free contact me .
Best regards,
Linda
From many years aluminium pot is the better boiling pot and also available in a very affordable price rather than stainless steel pot.
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Beer, a good reason to make smart decisions. Never done so much research on anything in my life. Can’t wait to get my setup complete, thanks for the article!
Thanks for the blog you have mention everything clearly about aluminum and steel. Still if you ask me personally i go with aluminum as it has lots of features as compare to steel. Not only this with the light weight, flexibility, durability it is been widely used in industries as well as for commercial purpose.
aluminum is easy to crush and stainless is hard so I prefer aluminum pots..
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Explained very well but still i think stainless steal is more strong than aluminium
Great job!
“Keep in mind that every day you drink soda from aluminum cans (though most are lined) and eat food prepared in aluminum cookware – it is safe.”
I smoke cigarettes everyday, I ain’t dead. – They must be safe!
Just saying, thats some pretty false thinking. Just cause you do it doesn’t make it right.
Spending too much time around beer geeks that will argue with a wall can lead one to have a heart attack or even worse, assault innocent the beer geek. Thanks for the article. Remember folks, breathing causes cancer because their are toxins in the air. And life is a terminal disease.
I know these comments are very old, but I’ll throw this out there to see if anyone is still listening / discussing. The major decision factor I see is aluminum and it’s superior heat transfer is best for applications using external heating (e.g. burners) as you need the heat to transfer through the kettle into the wort. SS would be better when using internal heat such as electric heating elements. This would slow the heat loss through the kettle. I’m currently looking to go electric and am considering SS for these reasons. Am I on the right track or is heat loss from aluminum with an electric element minimal?
I have been offered an aluminum pot for brewing but it has been used with oil to fry turkeys. The inner surface looks stained. Do you think it can be cleaned and used for Brewing? So is PWB good on aluminum or not??
I would use cream of tartar to remove the stains. I routinely make a paste of cream of tartar and water to clean my aluminum cookware. After you’ve cleaned the paste out of the cookware and boiled water in it your stock pot should be safe to use for brewing beer.
I use both and I don’t really see a practical difference. Thank you.
I just got in to the world of brewing but been around aluminum since the last ice age. If you are working on something heat sensitive then go with aluminum since it has good thermal absorption. The severe oxidation too can easily be sanded out and polished to a chrome finish. Though stainless steel is easily cleaned, hard steel, and stands out like a bling, i personally chose aluminum for brewing mainly because it is softer than stainless steel. Just in case the wife gets mad and start throwing things at me
I’ve used both over the years. I still use stainless for heating sparge water, because I have an old set of smaller pots that work, but I switched to a 10 gallon aluminum brewpot a couple of years ago. It’s much lighter (a great advantage as you get older) and has remarkably better heat transfer. Yes, you do have to condition it before the first use, but that’s not difficult, and you only do it once. To deep clean the pot after a boil, a careful wipedown with phosphoric acid and a thorough rinse gives excellent results and does not damage the oxide layer. I have never experienced an aluminum off-taste in my beers.