Well, I'm home in front of my notes and my recipe (used BeerSmith) yields an estimated SRM of 11.7 (right in the middle of the style). But, I'll just stick with the "yellow and malty" bru'n water calculations for now. Using the amounts previously mentioned earlier in the thread, it yields
Ca 50 ppm
Mg 5 ppm
Na 8 ppm
SO4 35 ppm
Cl 55 ppm
HCO3 61 ppm
est Mash pH of 5.3 and RA of 12.
In terms of Alkalinity and Hardness, Martin's graph pegs this water profile as similar to Dusseldorf.
When I went to create the new water profile in brewsmith, brewsmith's formula yields a significantly lower bicarbonate (24 ppm) level and slightly higher (by 5 ppm for SO4, and 10 ppmfor Cl, yet proportionally the same, so the "SO4/Cl ratio", as Martin calls it, should be unchanged).
I am a little puzzled by why Martin's spreadsheet lists the "SO4/Cl Ratio" (sulfate to chloride ratio) when most of the information out there talks about the "Cl/SO4 Ratio" (chloride to sulfate ratio). Just an inconsistency that I've noticed; it doesn't bother me much--I can do 1/x to get the ratio I'm used to seeing.
We'll soon see how it turns out. I plan to do it this weekend.
Gordon, I also read your section on BPA. Great info. I "blended" a few ideas from your book (BBB) as well as JZ and JP's book (BCS) and Drew B's "Seeing the Light: Belgian Session Beers" article in Zymurgy (May/June 2009).
Great advice by everyone. This is truly a "collaborative" effort.