Water, sediments and my new brew kettle?

[Erythro73]

Hi! After a three years hiatus (a house, new job, new dog), I decided to start brewing again. I bought a turkey fryer with a 36 quarts aluminum pot included (I do 2.5 gallons batches, so it's plenty). Today, I did as suggested in this thread https://www.homebrewtalk.com/f39/vs-pro-con-analysis-109318/ and I boiled tap water (4 gallons) for about 60 minutes (I wanted to know my boiloff rate too).

After the water cooled down, I took a look at the water and it was grey-ish, troubled and opaque. I kept a glass of it and, 4 hours later, I looked and there's some sediment on the bottom of the glass. Here's a comparison with a fresh tap water glass. http://imgur.com/ZwiXrNO and we can see sediment from the top on this one : http://imgur.com/YK3htDG

What happened? Is it toxic? Should I be worried? Is my tap water wrong or did my brew kettle shed some coating in the boiling water?

Here's some things that may be useful :

- I didn't wash the kettle beforehand. I have a rinsed it a bit with cold water, but I didn't use any detergent whatsoever.
- I chilled it with my very simple immersion chiller (yeah, I boiled it yesterday with vinegar, and then I rinsed it thoroughly)
- The kettle and the turkey fryer basket both went from shiny to brown to the original color (maybe a little bit more dull). The turkey fryer was there for 5 minutes of the boil, went brown and I removed it (and I know it's normal). Then, I put it back for 10 minutes and the brown color went away. Here's what they look like now : http://imgur.com/ImlMrMS,DRQnMVs#0 and http://imgur.com/ImlMrMS,DRQnMVs#1
- The cover was on for about 20 minutes of the boil
- About two or three grasses fell in (!!)
- My cat drank (unbeknownst to me) of the weird water and didn't die nor vomit. Might develop some feline superpower in the close future.

Any thoughts?

 

[Redhook]

Probably just oxidation from the aluminum. Did the kettle walls darken? You need to oxidize aluminum kettles before use.

 

[brewkinger]

Boiling the water causes calcium carbonate to precipitate. That is the white/gray suspended material in the water.
Do you know the mineral quantities in your water?


Sent from my iPhone using Home Brew

 

[Erythro73]

Boiling the water causes calcium carbonate to precipitate. That is the white/gray suspended material in the water.
Do you know the mineral quantities in your water?


Sent from my iPhone using Home Brew

No, I don't know the mineral quantities in my water. I looked it up online, but I never found anything. I decided not to bother calling as I just wanted to start brewing again a bit and wanted to keep things simple. I wanted to brew with half of my water coming from bottles and the other half from my tap.

However, tell me if I'm wrong here, but calcium carbonate in that quantity should not be a health hazard at all, as it was already in the water, right?

Furthermore, with calcium carbonate having precipitate, can it impact the beer (other than clarity)? Should I bother using gypsum?

Thank you!

 

[brewkinger]

First of all, my apologies. I was looking at the pics earlier on my phone and did not understand fully what I was looking at.

The gray/white material on the sides of the kettle is the oxidized layer that is NECESSARY to keep on the inside of an Aluminum kettle.
Do not scrub it off, it protects the kettle from the acidic wort and as long as it stays on the kettle, there will be no adverse effects/tastes on your beer.

As far as the suspended material in the water itself, my original comments about calcium precipitate are still correct.

Check out the Brew Science subforum for a little more in depth understanding about mineral content in your water, etc...

It is tough to answer the question about the effects of calcium carbonate on the taste of your beer because there is a lot of scenarios with regards to CaCO3.
As far as gypsum (calcium sulfate)[CaSO4]) is concerned, this also is something that can affect the taste and characteristics of your beer.