Accumash and other Water Adjustment Questions

Brewing Processes
1

Just starting to pay better attention to my water, and have not previously done much in the way of targeted additions.

Next up in the brew queue for me is a Witbier.  I have a supply of RO water for mash and sparge, and picked up a couple of packs of Accumash for SRM 2-6, OG 1.04 - 1.08.  My recipe design estimates an SRM of 2.8 (up to 3.4 if L of malt and flaked wheat vary) and OG of 1.039.

How well does the Accumash do at getting a decent water profile?  I’m guessing the packs I bought are approximate to a “yellow, balanced” profile.  Anyone find they need to make additional adjustments when using Accumash?

For the brew, I’m now looking at the Hoegaarden profile in Bru’n Water which probably isn’t achievable with an off-the-shelf product and I would be better off breaking out my chemistry set.  I’ve gotten fairly close playing with mineral and acid additions.  My mash pH is in the green at 5.54 (down from the estimate of 5.74 in Beer Smith, but above the target of 5.2).  Target vs. actual adjustment numbers show calcium, magnesium, and sodium numbers are pretty much spot on (+/- 1 ppm).  Sulfate is high (117 v 81), chloride is just a little low (42 v 49), and bicarbonate is way low (18 v 155).  The phosphoric acid addition, which brings the pH nicely into the green, seems to be killing the bicarbonate number with a -114ppm impact.  Should I be concerned with these outliers at all, or just focus on getting the pH inline and be happy I got most of the numbers close to the chosen profile?

2

Pay attention to the pH. The bicarbonate number will just drag the pH up, and more acid of Ca will be needed to bring it down. Less is more.

3

If the resulting beer tastes a bit flabby or dull, a post-fermentation addition of acid can do wonders for the flavor and perception. Adding 88% lactic at a rate of about 0.2 ml per gallon of beer should drop the pH by about 0.1 units. If you haven’t used any lactic acid in the mashing and sparging stages, you should be able to add up to 1 ml per gallon of beer and not create twang in the beer.