Aluminum kettle questions

ok-
So I'm getting ready to brew my first batch; an extract kit. I picked up a 20qt aluminum stock pot. For the dual purpose of forming an oxide layer, as well as testing just how much volume I can boil, I did a 'test run' last night. I filled 3 gallons of tap water into my primary bucket (just to measure) and noticed that my water had a blue/green tint to it, which leads me to believe that I have high levels of copper. I dumped this into the kettle and cranked up my gas stove. I had a candy thermometer clipped on to the side so I could monitor what's going on. Well, it took quite a while to get this thing going, after about 40 minutes it reached 190F, so I repositioned it over 2 burners. Not sure if this actually helped, or if I was just cooking on 2 half burners. Eventually, after another 20 minutes or so, it crept up to just about 210F, It never got to what I consider "boiling". I mean, the water was moving around, but not churning, bubbling, etc. Also - my smoke alarm kept going off throughout the whole thing, which I thought was very strange - I was just boiling water! I expected a cloudy dull oxide layer to form on the pot, but instead, the pot turned dark black - almost looked like soot in there. So my questions are:

1. Is the level of 'boiling' I achieved sufficient for brewing a LME? If not, how much less water can I use and still get a good batch?
2. anyone have any ideas what might have been going on w/ my smoke alarm, or why the pot turned completely black? Does this have anything to do with the copper in the water? I planned on using spring water when I actually brew, but will the already formed black layer have any affect on the beer?

Thx!

You should have a ROLLING boil for brewing. A quiet simmer is not generally considered sufficient.

I think the black residue is a good thing. I have read several places where people recommend boiling water in an AL pot to build up an oxidation layer on the metal to help avoid any off flavors from the AL during the boil. Not sure about the smoke alarm, any water or gunk on the bottom of the kettle?

As far as the stove/boil issue, I would say go get a turkey cooker and brew outside if that is an option. I think I get better results doing a full boil. Beer ends up lighter in color, better hop utilization, and this may all be perceived, but less extract twang.

Check out this thread. https://www.homebrewtalk.com/showthread.php?t=53683&highlight=improved+stovetop

I used this technique Sunday and it worked wonderfully. As far as the black, that is normal.

s3n8 said:

As far as the stove/boil issue, I would say go get a turkey cooker and brew outside if that is an option. I think I get better results doing a full boil. Beer ends up lighter in color, better hop utilization, and this may all be perceived, but less extract twang.

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I probably will, eventually. But since this is my first brew, I still don't have a wort chiller, etc. I want to remove as much of the complexity as possible.

Redweasel said:

Check out this thread. https://www.homebrewtalk.com/showthread.php?t=53683&highlight=improved+stovetop

I used this technique Sunday and it worked wonderfully. As far as the black, that is normal.

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Looks pretty cool. I might try that. If this does help the heat transfer, how many gallons can i boil in a 20qt without a boilover?

bringitonhome said:

Well, it took quite a while to get this thing going, after about 40 minutes it reached 190F,

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OMG I love my turkey fryer. I used to do boils inside and I forgot how long it took. I mash in my kettle and I go from cool water to 170 in maybe 10 minutes.

bringitonhome said:

Looks pretty cool. I might try that. If this does help the heat transfer, how many gallons can i boil in a 20qt without a boilover?

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I can easily get 6.5 gallons in a 30qt so I'd imagine you could get about 4 gallons going if you used some fermcap-s or some other type of foam control. You could go with three but still may have problems with boil over.

Also if you are doing extract with partial boils look up late extract addition.

Redweasel said:

I can easily get 6.5 gallons in a 30qt so I'd imagine you could get about 4 gallons going if you used some fermcap-s or some other type of foam control. You could go with three but still may have problems with boil over.

Also if you are doing extract with partial boils look up late extract addition.

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Yeah I've read about late extract addition in palmer's book. I think I'm going to try that also. I want to avoid the caramelization, etc. that he talks about.

Are there any 'household' methods for reducing boilovers, as in, something I may already have in my kitchen?

Spray bottle with cool water and lots of attention.