Question about following the brewing chemistry primer

I plan to brew this Munich Helles recipe next weekend.

https://www.homebrewtalk.com/f57/2011-1st-place-hbt-light-lager-augustiner-lagerbier-hell-238906/

My plan is to mix 3/4 distilled water with my tap water, which should result in pretty soft water.

In addition to the malts listed for the recipe, I also bought enough acidulated malt to make it approximately 3% of the grist.

So, if I add 1/2 tsp calcium chloride to each five gallons of my starting water mixture, and add the acidulated malt that I purchased to my grist, then am I following the 'brewing chemistry primer' recommendation correctly?

https://www.homebrewtalk.com/f128/brewing-water-chemistry-primer-198460/

Thank you,
Nathan

masaba said:

My plan is to mix 3/4 distilled water with my tap water, which should result in pretty soft water.

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That depends on what is in your source water. If it runs 400 ppm as CaCO3 calcium hardness and 400 ppm as CaCO3 alkalinity then the blend will be 100 ppm as each - not what you'd consider soft. If, OTOH, the source has hardness and alkalinity each equal to 100 then the 3:1 blend will result in water at 25 ppm for each and that is 'pretty soft' - soft enough anyway to be considered so for purposes of applying the Primer's recommendations.

masaba said:

So, if I add 1/2 tsp calcium chloride to each five gallons of my starting water mixture, and add the acidulated malt that I purchased to my grist, then am I following the 'brewing chemistry primer' recommendation correctly?

Click to expand...

Yes, you are but note that Helles is brewed with 'pretty soft' water so that, depending again on the properties of your available water you might want to increase the dilution and add less than 1/2 tsp/5 gal or go with all RO and add less than 1/2 tsp/5 gal. This is taking you beyond the Primer's KISS recommendations and you may not be ready to go there yet.

Thank you for the reply. It is a little difficult to tell exactly what the mineral content of the water from my tap could be. I receive a mixture of water from 2 sources, and I have available reports for each source listing avg, max and min concentrations for various minerals. So, my thought is to determine an approximation based on this information that errors on the side of 'worst-case' (i.e. high alkalinity). Using this technique, I come up with the following numbers:

Worst case: 117 PPM alkanlity, 170 PPM overall hardness

I actually expect something more along the following numbers

Expected: 55 PPM alkanlity, 89 PPM overall hardness, 25.6 PPM calcium

So, even in the worst-case scenario, I believe that I am still within the starting range that is specified in the primer.

Sound reasoning.