Aluminium mash tun?

[Weejock]

I have a large aluminium stock pot which takes 45 litres, normally used for making soup. (Big family!)

Soup "taint" aside, is the aluminium suitable for brewing purposes?

[MightyMouth]

I believe it is as long as it is clean through there has been some debate over it.

[CJBrew]

More than suitable, it's excellent. Don't listen to anyone who tells you that drinking beer brewed in aluminium will give you Alzheimer's disease. I'm convinced the only reason for this rumour is because both words start with "al".

The "alcohol" will rot your brain and kill you a lot quicker than any aluminium residue. Aluminium oxidises quickly and forms a hard outer layer, unless you really try you're not going to get much aluminium into the beer.

[WishboneBrewery]

I've got an Aluminium Stock Pot as my boiler.

Wonder if its degrading my...

...what was I saying..?

I'm not impressed with the weather today

[yashicamat]

Actually, I'd say aluminium as a mash tun is a less ideal material, simply because aluminium is a pretty good conductor of heat, compared with stainless steel for instance. Obviously though, all metals are going to conduct heat relatively well . . . .

[Weejock]

Done a bit of research, it seems metals reach detrimental levels in humans by contact and respiratory intake more than ingestion (is that a word?).

So for example drinking water from a lead water pipe is unlikely to give you lead poisoning, whereas lead based make-up or sanding down lead based paints is likely to.

Likewise aluminium in de-oderants is potentialy more harmful than aluminium cookware.

Anyway my original question was really asking if there would be any adverse chemical/taste reactions with the mash/wort/beer etc, I guessed if cookware was produced in aluminium it was inherantly human-safe.

Again, being a newbie to home brewing, why is heat conductance of the pot an issue?

[WishboneBrewery]

Again, being a newbie to home brewing, why is heat conductance of the pot an issue?

If its Pre-heated and insulated well I wouldn't see a problem.

[MightyMouth]

I think the heat conductance factor was in relation to using the pot as a Mash Tun as opposed to a Kettle. As a Kettle it would be a better conductor than a stainless pot so would heat up the wort faster but as a Mash Tun it would tend to lose heat faster which is something you want to avoid.

[Weejock]

Thanks MightyMouth, that makes sense.

[CJBrew]

I think the heat conductance factor was in relation to using the pot as a Mash Tun as opposed to a Kettle. As a Kettle it would be a better conductor than a stainless pot so would heat up the wort faster but as a Mash Tun it would tend to lose heat faster which is something you want to avoid.

... but I'd argue most of the important heat loss from a Mash Tun is radiative rather than conductive, so insulation is more important than the material your tun is made from.

Unless the metal is extremely thick (which it won't be) the difference in conductivity between the inside and outside of the vessel between a stainless steel and an alu pot is going to be fairly minimal, i.e. both will feel hot to the touch. But high thermal conductivity is an issue (and a Good Thing) if you're directly heating the vessel, whether it's a boiler or a Mash Tun. I have usually used a large alu stock pot as MT, and quite a few times have placed it on the kitchen hob and applied direct heat to either mash out or just adjust the temperature.
Aluminium is possibly less likely to result in scorching/burning in this usage.