Adjusting your water chemistry is one of those things that can make a good beer great.
Before you can adjust your water, however, you need to know what you're starting with because everybody's water is different. For that, you need a water report.
The problem with obtaining a water report here in Denver is that we are supplied by three treatment plants, and we don't know which one supplies us. I suppose it's even possible that the supplies are mixed and/or our treatment plant could switch depending on the season.
What this gives us is a bunch of unknowns, which is why the only way to really know what's in your water is to test what's actually coming out of your tap.
There are tons of companies which can test your water. You can find one on your own, but a trusted source for homebrewers is Ward Labs. They even cater specifically to homebrewers.
The website is a bit misleading. If you're browsing around trying to find the right spot, you'll probably end up on the brewer's kit order form page. They will send you a kit and conduct the test for $36. This isn't what you want. Instead, go to the Sample Submittal Forms page and scroll all the way to the bottom where there is a link that says “Information Sheet for Home Brewers.”
This form is what you want. Fill it out and send it in with your own bottle, following the instructions on the form and choose the “W-6 Household Mineral Test.” The
cost is $16.50 plus shipping Update: see Al's comment below for updated pricing. You can choose one of the other more expensive tests but everything you need is in the W-6 test.
Sending in the water sample
You need to send Ward 8-16 oz of water in a plastic container. My goal was to find a container that could hold that amount and fit into one of the USPS small flat rate boxes. It turns out that a 375ml bottle of cheap vodka did the trick. Pour out the vodka (but save it for filling airlocks, or drink it), rinse it, and fill it with your water sample.
I wrapped the lid in a paper towel and secured it with a plastic baggy and rubber band, just in case it leaked during transit.
The results were emailed to me 5 days after I mailed in the package. Very impressive turnaround.
Here is the actual water report I received via email from Ward, but I've also posted the results below.
- Sodium, NA – 17 ppm
- Potassium, K – 2 ppm
- Calcium, Ca – 31 ppm
- Magnesium, Mg – 7 ppm
- Total Hardness, CaCO3 – 107 ppm
- Nitrate, NO3-N – 0.2 ppm
- Sulfate, SO4-S – 17 ppm
- Chloride, Cl – 21 ppm
- Carbonate, CO3 – 6 ppm
- Bicarbonate, HCO3 – 66 ppm
- Total Alkalinity, CACO3 – 64 ppm
I'm not going to go too much into analyzing my sample in this post because this is more about obtaining the report.
One thing I want to point out is the difference between my sample and the Denver Water reports. As mentioned above, there are three treatment plants and I do not know which one supplies my house. From looking at their report, the Marston plant numbers are very close to mine, so there's a good chance that is where I get my water. Of course these are yearly averages and I may in fact get my water from a different plant in the winter. I do plan on sending in another sample in the winter just to see how the numbers change.
It gives me peace of mind to know my water profile. Let me know in the comments if you've had your water tested as well.