FAQ: Aluminum Pots for Boil Kettles?

I was shocked today, pulled out my old turkey frying stuff, since I never do that anymore. Sprayed out the 30 quart aluminum pot I used to use, filled it 2/3 full with hot water, threw it on the singe burner I used to use, and was shocked, i had about 20 quarts of water boiling in 15 minutes.

For those who live in Indiana and Michigan http://www.atlasrestaurantsupply.com/ is a good place to go. I buy all my regular cooking pot n pans from them. good prices for an item designed for the daily abuse of a restaurant.
The different styles and sizes of pots/kettles you can order on site is immense.

Find out if you have a local restaurant supply store in your area and take a look.
they do not advertise and usually hidden away in a cheep rent building. they are selling a product not an image.

Edit - i just realized wile looking at there vender list that perlick is one of them.

Head's up to anyone using an Aluminum pot:

So, I got an amazing deal -- a turkey fryer at a garage sale for $10. Didn't they know what this can be used for?!

I read about baking the pot. Check. I read about the stainless/aluminum pros and cons. Check. I did not catch the "Don't use PBW" clause. The pot is now pitted and nasty.

So, warning to newbies out there: When the FAQ says do not use caustic cleaners, it's serious. NO PBW.

For what it's worth, I'm going to keep using it. The only downside is that my 4.5 gallon stainless pot is wide enough to get to a rolling boil on my gas kitchen stove. The turkey fryer is too tall. It needs a better burner. So, it's more of a fair-weather friend.

No big deal, I would scour the heck out of it, with a scrub pad or perhaps with medium then fine sandpaper. Then oxidize it again. Aluminum is soft and can be refinished ala ghetto style.

I have a related question, 2 actually. If I have used oxy based cleaners on aluminum and have removed some of the oxide, is there a way to restore it? Also, if I inherit an Aluminum pot that has been used, is there a way to ensure that it has a proper oxide barrier in place? I bought aluminum cam locks and have used oxyclean on them about 4 - 5 times now. I also may be getting a couple used (party supply store rentals) 15 gallon pots.

Thanks.

Picked up a new 48L aluminum pot yesterday.

I boiled about 26L in it to build up the oxide layer.

As seen in the picture, it's quite dark up to where the water line was.

As long as I'm never boiling more than around 23L of wort, should I be worried about the upper half of the pot not having the oxidation layer?

No, I would say you are fine regardless of your intended boil volume, aluminum oxidizes very easily and a preboil is merely a precaution...RDWHAHB cheers

is there any evidence of metal interaction that would prevent me from using an aluminum pot with a stainless bulkhead ?

thanks- Lou

You're on the edge for recommended galvanic corrosion limits. Stainless is a .5V and aluminum is between .75-.95V. For normal environments they recommend less than a .25V difference. Wouldn't be the worst idea to disassemble after uses.

Source: http://www.engineersedge.com/galvanic_capatability.htm

Majic said:

is there any evidence of metal interaction that would prevent me from using an aluminum pot with a stainless bulkhead ?

thanks- Lou

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scottland said:

I've been using the same 32QT aluminum pot for years. Started out life as my boil kettle, then I put a 4,500w element in it, and it became my electric boil kettle. These days it's my electric HLT. It's still trucking along. Stainless fittings, and no signs of corrosion yet.

The entire pot acts as a sacrificial anode if you use it with an electric element. In theory, the entire pot will eventually wear out. It could be decades before that happens, and if it ever does, it was only a $22 pot.

If you are using propane, my setup is a worst-case scenario by comparison, and I've had zero issues. Carry on =)

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You are likely very fine and this is not a problem at all for your intended infrequent use as a homebrewer. This type of corrosion is more pertinent to structural applications, plumbing of pressure vessels, or marine environments. I would be more concerned of a lightning strike during a brew session than the stainless fitting on your aluminum pot...cheers!

https://www.homebrewtalk.com/f14/aluminum-pot-stainless-fittings-372245/

http://wiki.answers.com/Q/Will_stainless_steel_react_when_in_cotact_with_aluminum

Well. I just bought a 40qt aluminum pot and am putting a 1500w element to supplement my stove. And a drain valve. It is my own fault for not looking up the galvanic corrosion issue. But reading above puts me at a bit of ease.

I havent been able to find any definitive information on this in off the SS vs Al pot discussions. But do you think there is any noticable difference in propane usage given the fact that the thermal conductivity of Al is so much better than SS. For reference the conduction coefficient of Al is 250W/mK where SS is only 16W/mK

Found this on the internet though

Example - Conductive Heat Transfer through a Aluminum versus Stainless Steel Pot
The conductive heat transfer through a pot wall can be calculated as

q / A = k dT / s

where

q / A = heat transfer per unit area (W/m2)

k = thermal conductivity (W/mK)

dT = temperature difference (C)

s = wall thickness (m)

Conductive Heat Transfer through Aluminum Pot Wall with thickness 2 mm and temperature difference 200C
q / A = 250 (W/mK) x 200 (C) / 2x10^-3 (m)

= 25000 (kW/m2)

Conductive Heat Transfer through Stainless Steel Pot Wall with thickness 2 mm and temperature difference 200C
q / A = 16 (W/mK) 200 (C) / 2 10-3 (m) = 1600 (kW/m2)

Well most Al kettles are 4-6mm thick and most SS kettles are .8-1.2mm thick so here's the updated #'s:

Conductive Heat Transfer through Aluminum Pot Wall with thickness 5 mm and temperature difference 200C
q / A = 250 (W/mK) x 200 (K) / 5x10^-3 (m)

= 10000 (kW/m2)

Conductive Heat Transfer through Stainless Steel Pot Wall with thickness 1 mm and temperature difference 200C

q / A = 16 (W/mK) 200 (K) / 1x10^-3 (m)

= 3200 (kW/m2)

So the aluminum will conduct heat in at a rate 3 times more than the stainless BUT it will also conduct heat out 3 times quicker too. Since there is more wall area than bottom area the heat lost may equal out the Al and SS or Al may end up losing more heat due to the large wall surface area and higher conductivity.

I'm cheap, so I use aluminum pots that I get for tamales. A 52qt pot for $30, you can't go wrong. I did notice, when I was oxidizing them, they actually retained the heat pretty well. It was in the high 40s over night outside, they were still over 120 degrees the next morning. (After about 7 hours)

passive oxide layer must be built up before brewing (**see note below) with a new aluminum kettle, although it is very easy to maintain

Where is the note that says how to do this?

Hall_Brewing said:

passive oxide layer must be built up before brewing (**see note below) with a new aluminum kettle, although it is very easy to maintain

Where is the note that says how to do this?

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Just fill it up and boil water in it for at least an hour before you use it. Personally, I did 2 hours but kept topping it off as water evaporated.

xtian116 said:

Just fill it up and boil water in it for at least an hour before you use it. Personally, I did 2 hours but kept topping it off as water evaporated.

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Overkill, IMO.

Just take it out of the box and use it. It will be fine.

CGVT said:

Overkill, IMO.

Just take it out of the box and use it. It will be fine.

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Yea I'm tempted to agree here as well...perhaps a little cleaning prior to use is warranted, but I agree that the level of concern for oxidizing aluminum pots is overstated...aluminum will oxidize plenty through use.

I've never read a post, "first batch ruined, didn't oxidize my kettle". Aluminum oxidizes to some extent in air almost instantly.

wilserbrewer said:

Yea I'm tempted to agree here as well...perhaps a little cleaning prior to use is warranted, but I agree that the level of concern for oxidizing aluminum pots is overstated...aluminum will oxidize plenty through use.

I've never read a post, "first batch ruined, didn't oxidize my kettle". Aluminum oxidizes to some extent in air almost instantly.

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Your both probably right. When I first started I don't even think I cleaned that turkey fryer when I un-boxed it. Figured is was going to be boiled. When I got my bigger pots, I was a little overkill on them because I wanted them to look like the old ones. Maybe it was my brewing that got better and not the layer on the pot.

Just ruined an aluminum kettle with oxy clean...... lesson learned read first! Correction read everything first....

CraigHathcock said:

Just ruined an aluminum kettle with oxy clean...... lesson learned read first! Correction read everything first....

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Unless there are holes in it, I can't see it being "ruined". If it is just very ozidized and black inside, that is not ruined IMHO.

It's probably not ruined. The oxiclean removed the oxide layer. Re-boil and you should be good to go.

Great FAQ, flyguy!

Sounds like FlyGuy was simply trying to do a good thing...
Also sounds like abracadabra was having to be the fly in the ointment, no pun intended
Thanks FlyGuy for doing what I set out to find, having a question answered

I'm sure it's fine. But even with caked on and burnt sugar I can take the top rack out of my dishwasher and it fits in there. I had a boil over my first solo boil and it was a mess but it still looked new out of my dishwasher.

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Anybody read the "Toxicology of Metals" by Luis W. Chang Ph D? There is an entire chapter (23) on Alzheimer's Disease by D.R. McLachlan, P.E. Fraser, E. Jaikaran, and W.J. Lukiw. A good read. People can say Aluminum is fine all they want, but I'm not taking the chance. I thought it was an interesting sentence in the book "The long-accepted commercial use of aluminum and its compounds has led to considerable resistance to investigating the possible role of aluminum in human disease." The conclusion on Page 395 also states that there is "robust evidence" that aluminum is involved in AD.

Question, I had a house fire and my aluminum pots were very close to the fire, they are not deformed yet they are a bit scorched. Since Aluminum is porous, it would have absorbed a ton of soot and I'm wondering if this will impart off flavors to my beer?

Insurance is paying to replace what got ruined so before I decide to trash these pots I'd like to know if they're no good for brewing.

p40whk said:

Insurance is paying to replace what got ruined so before I decide to trash these pots I'd like to know if they're no good for brewing.

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Warhawk, will they pay to replace the pots? If they are, they usually let you keep the old ones. You could then brew a test batch and educate the rest of us.... Just sayin.

I'm probably going to replace them as I really don't want to have those flavors in my beer. Not to mention that they got pretty hot by the fire then doused with that chemical foam the fire department used to put it out. Not sure if it's safe to use or not but I could boil something in it to find out.

NewBrewer_B said:

Anybody read the "Toxicology of Metals" by Luis W. Chang Ph D? There is an entire chapter (23) on Alzheimer's Disease by D.R. McLachlan, P.E. Fraser, E. Jaikaran, and W.J. Lukiw. A good read. People can say Aluminum is fine all they want, but I'm not taking the chance. I thought it was an interesting sentence in the book "The long-accepted commercial use of aluminum and its compounds has led to considerable resistance to investigating the possible role of aluminum in human disease." The conclusion on Page 395 also states that there is "robust evidence" that aluminum is involved in AD.

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yup its been mentioned here many times...
Its just like the old cellular phones and the "silver" tooth filling they used (and still use) that are actually made of heavy metals including mercury.... this stuff will SLOWLY be phased out as to not cause panic and billions in lawsuits.

And While they are certainly not the best choice (may I remind you that Drinking alcohol isnt exactly the healthiest thing for your body either) in most cases it wont cause any serious harm...(depending on who you talk to and how much exposure is involved).
the sad fact is until someone provides inconclusive proof and shows this to the RIGHT people nothing will be done either way. and maybe the threat just isnt that real?

augiedoggy said:

yup its been mentioned here many times...
Its just like the old cellular phones and the "silver" tooth filling they used (and still use) that are actually made of heavy metals including mercury.... this stuff will SLOWLY be phased out as to not cause panic and billions in lawsuits.

And While they are certainly not the best choice (may I remind you that Drinking alcohol isnt exactly the healthiest thing for your body either) in most cases it wont cause any serious harm...(depending on who you talk to and how much exposure is involved).
the sad fact is until someone provides inconclusive proof and shows this to the RIGHT people nothing will be done either way. and maybe the threat just isnt that real?

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The difficulty with studying the effects of aluminum exposure is that it is EVERYWHERE in the environment. It is the 3rd most abundant element on Earth. It's in spinach, tea, and drinking water. Should you stop eating spinach, drinking tea, and drinking water?

Alzheimer's has also been blamed on flu shots and silver dental fillings. Those have also been disproven. The only solid ties to Alzheimers found so far are genetics, metabolic and vascular disease, and the lack of intellectual stimulation. Like almost all diseases the best prevention is to eat right, exercise more, and pick good grandparents.

wilserbrewer said:

Yea I'm tempted to agree here as well...perhaps a little cleaning prior to use is warranted, but I agree that the level of concern for oxidizing aluminum pots is overstated...aluminum will oxidize plenty through use.

I've never read a post, "first batch ruined, didn't oxidize my kettle". Aluminum oxidizes to some extent in air almost instantly.

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So true I bought an aluminum pot 4 years ago and make beer that tastes pretty good

I bought a 20 year old 10 gal aluminum pot from a home brewer. It has well oxidized coating and is thick enough to use as a car jackstand. I boil and mash in keggles but it is a great hot liquor tank and backup boil kettle. Hard to beat for $20.

I don't reckon there are a lot of commercial kitchens using SS, certainly the Michelin star kitchen I worked in when younger was all aluminium pots. My aluminium pots are probably 4mm thick and solid as a rock, I wouldn't switch 'em for cheap SS any day.


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This is great stuff. One question, do you have to continue to build the passive oxide layer on AL pots before each brew or is once enough?

tvic31 said:

This is great stuff. One question, do you have to continue to build the passive oxide layer on AL pots before each brew or is once enough?

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Once is enough, and then each time you brew normally, the oxide layer will maintain itself

Is there any other way to build up the oxide layer other than boiling water or placing it in the oven? I read somewhere that filling it with water and letting it stand overnight would build up the oxide layer or even adding some oxyclean to the water would build it up. This seems too simple so I am curious to know if it is true.

msa8967 said:

Is there any other way to build up the oxide layer other than boiling water or placing it in the oven? I read somewhere that filling it with water and letting it stand overnight would build up the oxide layer or even adding some oxyclean to the water would build it up. This seems too simple so I am curious to know if it is true.

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I'm sure leaving it overnight will start the layer, but boiling the water for a few minutes(maybe 20 minutes at least) and then dumping the water out while it is still hot makes a real nice layer. If you are worried about wasting the energy of boiling water, use the water you boiled for dishes or washing clothes or the bath, at least then no energy was wasted

I took mine right from the box and used it to brew beer. I wasn't worried about conditioning the pot. I doubt that restaurants condition their aluminum pots before using them. My beer was fine and I haven't grown a third arm out of my forehead yet.

zefbrew said:

I'm sure leaving it overnight will start the layer, but boiling the water for a few minutes(maybe 20 minutes at least) and then dumping the water out while it is still hot makes a real nice layer. If you are worried about wasting the energy of boiling water, use the water you boiled for dishes or washing clothes or the bath, at least then no energy was wasted

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I should have been more clear in my original post. I was questioning the science (is it true) about just using water over night to condition the pot. I will boil mine and use the water for chilling later in a cold ice bath.