[tygo]

I filled them both at the same time.  Tap water into the brita then into the sampling bottle for one.  And tap water directly into the sampling bottle for the other.

[tschmidlin]

Well, maybe someone who understands the water tests better an explain why it would increase that much.  Maybe someone who does water testing for a living . . .

Was it a brand new filter, or had you run a bunch of water through it already?

[denny]

Well, maybe someone who understands the water tests better an explain why it would increase that much.  Maybe someone who does water testing for a living . . .

Calling Martin!   

[tygo]

Well, maybe someone who understands the water tests better an explain why it would increase that much.  Maybe someone who does water testing for a living . . .

Was it a brand new filter, or had you run a bunch of water through it already?

Now you're asking my brain for too much 

I didn't really have anything in mind when I did it so I didn't pay attention to the variables.  I'm planning to submit another sample in a month or two.  Maybe I'll do another run at it in the name of brewing science. 

[malzig]

Here's what a Brita filter did to my water:

Tap:
Potassium   3

Brita:
Potassium   18

I'm surprised too.  Did you take the tap water sample at the same time as the brita sample, or were they some weeks/months apart?  The reason I ask is because of the ones that increase.  Sodium is probably within the margin of error, but potassium going from 3 to 18 seems like a big change.

Brita filters are good at removing temporary hardness, as well as metals, but gradually release potassium into the flow through.

[Kaiser]

That beersmith article was not peer reviewed, was it?  There are several things I just don't agree with.

me neither. He got quite a number of things mixed up.

Kai has some information, read his page after Palmer.
http://braukaiser.com/wiki/index.php/Understanding_Mash_pH

This article is rather old and I hope to be able to completely replace it soon. Here is a more recent one that does a better job in explaining what minerals in the water do to the beer:

http://braukaiser.com/wiki/index.php/How_to_read_a_water_report

Kai

[tschmidlin]

Here's what a Brita filter did to my water:

Tap:
Potassium   3

Brita:
Potassium   18

I'm surprised too.  Did you take the tap water sample at the same time as the brita sample, or were they some weeks/months apart?  The reason I ask is because of the ones that increase.  Sodium is probably within the margin of error, but potassium going from 3 to 18 seems like a big change.

Brita filters are good at removing temporary hardness, as well as metals, but gradually release potassium into the flow through.

So it's in the filter?  I thought it was just carbon in there.  Good to know.

[Kaiser]

I didn't know that BRITA is more than just a carbon filter. They also contain an ion exchange resin:

http://www.brita.net/uk/faqs_household.html?L=1#27:

The content of the original BRITA cartridge is an experienced mixture of ion exchange resin and activated carbon, which is particularly suitable for this type of drinking water conditioning.

Kai

[jamminbrew]

Send a sample to Ward Labs and request the W-6 Household Water Test for $16.50.  www.wardlab.com

I just called my utility company to ask for a water report.  They put connected me to their water chemistry expert (I forget the official title) and she emailed me a detailed, recent rport on the wate quality not only for the city, but for my particular sub-station as well, and it was free.

[tschmidlin]

Send a sample to Ward Labs and request the W-6 Household Water Test for $16.50.  www.wardlab.com

I just called my utility company to ask for a water report.  They put connected me to their water chemistry expert (I forget the official title) and she emailed me a detailed, recent rport on the wate quality not only for the city, but for my particular sub-station as well, and it was free.

You're lucky to get that kind of service.  My water utility office is completely unhelpful.  They don't have a water chemistry expert on staff that I know of.  It's really a tiny operation, but fortunately the water is excellent.

[malzig]

Yes, ion exchange and carbon.

Here's what a Brita filter did to my water:
Tap:

Calcium   46
HCO3   121
Total Alkalinity   99

Brita:

Calcium   8
HCO3   16
Total Alkalinity   13

I always stayed away from using a Brita filter for brewing water because I knew it removed calcium.  However, for brewers with high HCO3 alkalinity, it might be a very good choice.  You can always add Calcium back and the water will probably taste better thanks to the activated Carbon.

[jeffy]

Send a sample to Ward Labs and request the W-6 Household Water Test for $16.50.  www.wardlab.com

I just called my utility company to ask for a water report.  They put connected me to their water chemistry expert (I forget the official title) and she emailed me a detailed, recent rport on the wate quality not only for the city, but for my particular sub-station as well, and it was free.

You're lucky to get that kind of service.  My water utility office is completely unhelpful.  They don't have a water chemistry expert on staff that I know of.  It's really a tiny operation, but fortunately the water is excellent.

I'm lucky to have a good friend as the lab scientist at my local water treatment facility.  He runs my well water through the system tests for me at no charge, but I get the feeling he's doing it on the sly.  Occasionally he'll test other club members' well water for me, too, but I don't want to overstep my friendship and get him fired.

[hopfenundmalz]

Send a sample to Ward Labs and request the W-6 Household Water Test for $16.50.  www.wardlab.com

I just called my utility company to ask for a water report.  They put connected me to their water chemistry expert (I forget the official title) and she emailed me a detailed, recent rport on the wate quality not only for the city, but for my particular sub-station as well, and it was free.

You're lucky to get that kind of service.  My water utility office is completely unhelpful.  They don't have a water chemistry expert on staff that I know of.  It's really a tiny operation, but fortunately the water is excellent.

My water utility is completely unhelpful, and the water is pretty crappy.   

[mabrungard]

I have to admit that I thought that the Brita filters were only activated carbon filters.  Didn't know that they also include a cation exchange resin.  

I see that the cation exchange resin is charged with potassium instead of sodium which should reduce its impact to brewers.  

I'm a little surprised by the reduction in total dissolved solids.  If it were just the reaction from the cation exchange resin, the TDS would remain similar.  But, it appears that the filter also decarbonates the water as it passes through.  That causes the Ca and CO3 to precipitate onto the activated carbon surface.  That is the reduction in temporary hardness that is touted by Brita.  

I wouldn't call the filter worthwhile, but it doesn't really hurt the brewing water.  Go for it.

[malzig]

I wouldn't call the filter worthwhile, but it doesn't really hurt the brewing water.  Go for it.

Really?  There's an awful lot of people that want to reduce the HCO3 in their brewing water.

It should also remove much of the organic compounds that can make surface water taste foul in the warm weather.