water help with baltic porter

[Liquisky]

Since I was told on another forum by some respected brewers (AHA forum) that my tap water was not good brewing water I’ve been trying the water primer using RO water and adding acid malt and calcium chloride and gypsum as it suggests for different brews. The pale ales and wheat bears have been among my best but my smoked porter was thin bodied and was not great.
I’m in El Paso TX and my water report can be found here: http://www.epwu.org/water/pdf/chemanalysis.pdf (I'm on the West side and have a mix of sources 1 and 2).
I plan to make a baltic porter with brettanomyces (published in the latest Zymurgy magazine) and I would like to set myself up for ssuccess.
I don’t have a pH meter. I know I need to get one to be a better brewer, but I don’t have one yet.

My question is, what should I do to my brewing water as a best guess without having a pH meter? The primer says for porters to use 1tsp (5gm) CaCl to 5 gal of soft (i.e. RO water). But others have said the water needs some alkalinity. Others say you have to measure pH before adding anything else. Could I use some store bought spring water to add to the RO water to raise alkalinity?

This is the recipe:
100% Brettanomyces Baltic Porter (for 5.25 US gallons)
5lb 2-row pale malt
7.25lb10L Munich malt
1lb Simpson naked golden oats
12oz 60L crystal malt
12oz special b malt
5.28oz chocolate malt
5.28 oz carafa II malt
0.88oz glacier hop (first wort hopped)
0.53 oz glacer hops (30 min)
Brettanomyces yeast
Thanks for any suggestions.

 

[mabrungard]

The tap water has a lot of mineralization. That could be a good thing if you are diluting with RO. That way you can get some of the benefit of the hardness and alkalinity while moderating the overall mineral content. The main thing you were probably lacking in that smoked porter was alkalinity. Hopefully you didn't add any acid malt in that case since it would be counterproductive.

The Water Primer is very helpful for the lighter colored styles, but might not produce great results when the grist acidity gets high. Alkalinity may be helpful in that case. I suggest that Bru'n Water could help you figure out what the effect of diluting your tap water to varying degrees will be on your next beer.

 

[ajdelange]

The recommendation of the Primer represents a best guess but as a guess it can be dead wrong. You may indeed need some alkalinity. The only way to know for sure is to either
1. Get a pH meter and measure mash pH
2. Brew the same Porter with and without some supplemental alkalinity and see which brew is better.