Bru'n Water and Post boil concentrations

I have very soft water so for lighter colored beers, I use bru'n water to add just enough to get me over 50 ppm calcium with CaCl2 and then add some gypsum to balance out the Cl2.

So for example I'm brewing a saison and adding 4.8g gypsum and 3.9g CaCl2 (split between mash and sparge) to 9.6 gallons water. I arrive at 62 ppm Ca, 77 Sulfate, and 60 chloride. I add 2 oz acid malt to get my mash pH to 5.3. These additions are split between the mash (3.4 Gallons) and the sparge (6.2 Gallons).

I'd like to back off the mineral additions. I've been thinking that these ppms are calculated based on pre-boil water. So my reckoning is that if I have 62.2 ppm Ca in 9.6 gallons water (mash and sparge), I will have more than that post-boil (5.5 gallons). Like 62.2 * 9.6 / 5.5 = 108 ppm.

Is it reasonable for me to back off the sparge water additions? Does my logic make any sense? Thanks in advance.

Edit: Well I just found this thread which answers the second question. I would still welcome any opinions on my first question.

https://www.homebrewtalk.com/f128/mineral-concentrations-based-pre-boil-post-boil-volume-277106/

I think you may be reading too much into it. Its creator, Martin, is highly regarded in the brewing community for his water knowledge. My beers have dramatically changed for the better since using it. Just done want you making more work for yourself

I guess I don't consider thinking about/trying to optimize my water profile to be making too much work for myself.

I think I'm considering cutting my sparge water additions (which I actually add at beginning of boil) in half for pale beers. I've been trying to read through the brewing water chemistry primer in the brew science forum. I'm only on page 7 or so but this is the thought I am getting from it.

Yes, you are reading too much into the importance of calcium and the resulting concentration of ions through the boil. Trying to extrapolate what the ionic concentrations are after the boil is full of potential error since one brewer's boil may not be similar to another. In addition, we need to understand that malt adds a LOT of ionic content to the wort.

You can brew with distilled water and still have a bunch of calcium in your wort. The issue is that we brewers have empirically found that having around 50 ppm calcium in the starting water is good for helping ale yeast flocculate. Most brewers like their beers to clear in a reasonable amount of time. Conversely, lager brewers are not as interested in quick flocculation since they lager their beers and the yeast will fall out of suspension eventually.

So, 50 ppm is not a sacred level of calcium for brewing water. There is more than that level in wort made with distilled water and the yeast need very little calcium for their health.

Now I do have a minimum calcium level that most brewers should strive for and that is to provide at least 40 ppm IN THE MASH to help precipitate oxalate from the wort. That oxalate can cause beerstone problems around the brewery and it MIGHT promote kidney stones in beer drinkers if not precipitated (inconclusive). So you can have this minimum level in the mash and then dilute it with low calcium water and the beer will turn out fine. Some lagers benefit from low mineralization while other beers have improved flavor with more mineralization (ie: pale ales).

So, its not worthwhile to consider the concentrating effects of the boil on ions. Just standardize on targeting pre-boil concentrations in your water and alter those concentrations with subsequent brews to produce the results you prefer.

Don't overthink it! Enjoy.

Thanks for the reply. I gathered most of what you are saying from the thread I found that I linked in my first part but I appreciate the elaboration. And it makes sense too, if you've seen any of those threads where people are analyzing lab results from a can of Heady Topper and trying to figure out how to duplicate it. This seems it would be impossible unless you were going to start with a fixed grain bill and water profile, brew the beer, and then have your own lab test on your own beer and then adjust water profile to get closer.

Interesting what you say about beerstone. I had a case of it on the bottom of my aluminum pot after only about 7 or 8 brews. Not sure if that's normal or not.

I see that I need to worry about what's going on in my mash and other than that I might experiment with cutting my sparge additions. I went to a "homebrewer's Huddle event" at a local prominent brewery who brews belgian styles (very well I might add). I asked the guy if they treated the water (we have the same source from a nearby lake) and he said no they do not add anything. I wasn't really sure if I believed him but maybe they don't. I see how they could get by with most of the beers but they do make a stout so I'm not sure how they pull that off without messing with the water, perhaps the roasted grains are added after the mash. I mean there is practically nothing in our water.

I'm not convinced post-boil or post-ferment concentrations is not worth thinking about. For example, if sulfate is going to accentuate hop character, this is a post boil phenomenon, and is obviously at least partially influenced on the starting water and level of reduction. If people are going to use the "it's just like cooking" example... If I'm making a stock, and plan on reducing it down, I need to think about the flavors I'm putting into it up front so I don't concentrate those too much. I realize it's a bit more complicated then that but you get my drift.