Large acid additions

As many have, I noticed acid additions in BS3 that were much larger than Brew'n Water. While altering water profiles in a few recipes using the BS3 tool I noticed that BS3 appears to use Baking Soda in every recipe. When I deleted those additions the acid additions became very reasonable. IMHO, there is no reason to add baking soda unless you need to increase ph. Using additions of both baking soda and acid is like adding and subtracting the same amount to and from a given number and expecting a different a sum.

After selecting a water profile, and before going to the mash tab to look at ph, try deleting the baking soda additions and see for yourself.

That's interesting because the one time I tried to adjust the PH with acid it told me to add a huge amount, about 10x what Bru'n water said. Needless to say, I dumped most of that water and added new. It was tap water so not too bad

I also noticed BS3 asked for much higher acid additions than BruNWater.  I use 10% Phosphoric.  My first brew with BS3 was a Nugget Nectar clone, where the grist is all base malt (Vienna, Pilsner, and Munich); BS didn't call for baking soda, but it did ask for a lot more acid than BruNWater - 72mL vs 27Ml.

I followed BS, and found my actual pH (using a new Hach pocket pro+ that passed a 2-pt calibrations that morning) was 5.25 versus the 5.4 target.  Not as low as I was afraid it would be given the difference in the amount of acid.

I'll keep an eye out for the baking soda issue; I agree, I see no need to use baking soda and acid.

I just noticed the same issue. Never used Bru'n Water before, but when I saw the amount of acid that BeerSmith was telling me to use, I wanted to get a second opinion. While I did already delete the baking soda, BS is telling me to use about double the Lactic acid or Acidulated Malt that Bru'n Water is telling me to use. Based on my gut, as well as what you guys said, I'm going to lean toward the Bru'n Water numbers!

I just heard back from Brad on this. (By the way, I am super impressed by his customer support for this software.)

Brad Smith:
BeerSmith uses the "mph" model which is examined in detail on the link below.  The model is generally better than BNW because BNW ignores acid density when estimating the acid to use.  In fact in the linked paper there is a comparison of the various models and you can see that BNW is the outlier due to this error - it overestimates acid effects.

Here is the detailed paper including a comparison of models:
  http://homebrewingphysics.blogspot.com/2013/09/a-homebrewing-perspective-on-mash-ph-ii.html

Keep in mind these are all models and none of them are perfect, but I selected the mph model based on the best available methods.

Click to expand...

I already bought my grains for this weekends brew, so it will be interesting to see how the mash pH turns out. I figured its better to err on the conservative side, so I went with Bru'n Water's suggested Acidulated Malt addition. I will take a pH reading after dough-in and see where the pH falls...and then adjust my recipe from there.

I downloaded the mph model and tested it out with my Pilsner formulation and it comes out really close.  I noticed that the % acid rating for the acidulated malt in the model is set to 3% which matches my projection from the results versus the various models. My analysis of the software models and comparison to results is posted here: http://www.beersmith.com/forum/index.php/topic,18828.0.html