Seeking opinions on my water

I received the results from Ward Labs.

pH 8.1
Total Dissolved Solids (TDS) Est, ppm 510
Electrical Conductivity, mmho/cm 0.85
Cations / Anions, me/L 9.0 / 9.6

Sodium, Na 40
Potassium, K 3
Calcium, Ca 113
Magnesium, Mg 19
Total Hardness, CaCO3 362
Nitrate, NO3-N 0.1 (SAFE)
Sulfate, SO4-S 26
Chloride, Cl 84
Carbonate, CO3 12
Bicarbonate, HCO3 318
Total Alkalinity, CaCO3 281
Total Phosphorus, P < 0.01
Total Iron, Fe < 0.01

I have played around with this information in the Bru'n Water spreadsheet. I brew a variety of styles, but mainly focus on IPAs. I am an all grain brewer. I read the primer and I am am trying to learn more about treating my water for brewing beer. I have a pH meter.

From every thread I have come across, I think my bicarbonate is high compared to most. It is my expectation that this level will make it difficult to get an ideal mash pH. So generally, I think I should plan to use 100% RO water. I have RO treatment at my house. The water runs through a softener first. The tank only holds 2-3 gallons, so I think I am going to buy about 10 gallon jugs of RO water to start out and then just keep filling the jugs for subsequent brew days. I plan to add .4 gram/gal Calcium Chloride, .4 Epsom Salt and .5 Gypsum to get near the recommended ranges for the Amber Bitter profile on the Bru'n Water spreadsheet. I was thinking of using about 2% acid malt in the grain bill. The way I have entered the info to the spreadsheet, it estimates a mash pH of 5.3.

I was thinking of using the RO water for the sparge as well with the same mineral additions.

Anyway, the reason for the post is to see if anyone can let me know if I am messing this up. Or if there is a better approach in my situation. Sorry for the long post and thank you for any help.

Actually, given a measured alkalinity of 281 and a measured pH of 8.1 your bicarbonate is closer to 338 that 313 (and your carbonate more like 2.5). Which is why I wish people would focus on alkalinity. But more to the point your alkalinity is high. There are several things you could do about this but given that you have RO water available that is most certainly the simplest, most dependable option.

Your planned additions (including the sauermalz) are a reasonable place to start out though you could skip the Epsom salts. Is there a better approach? I don't think so. Do you have the optimum formula? The odds against that are very high and I certainly encourage experimentation.

Given that you own a pH meter it would be wise to prepare a small amount of the grist and a small amount of the water and mash them checking the resulting pH. Do this before brew day and make adjustments to sauermalz addition levels based on what the test mash shows.

Since you have RO water, it will be a welcome addition for creating your brewing water. The tap water is not a total disaster, but its far from ideal for brewing due to the high alkalinity. However, the tap water will be a good resource for alkalinity in those few brews that might need it. Blending with RO will solve that need. For most brewing, starting with pure RO may be most expedient.

I'll differ from AJ's recommendation regarding the magnesium added by the Epsom Salt. If you are looking for improving the bitter perceptions in a beer, I find that magnesium is an important component.

The reason most advocate skipping the epsom salts is that malt itself contains something like 0.15% magnesium w/w. If you mash 0.5 kg malt with 2 L of water (a bit less than 2 qts/Lb i.e. a pretty loose mash) you would then potentially have 375 mg/L magnesium in the water. I say potentially because some of this will be bound. By comparison, adding 1 gram Epsom salts to 1 gallon of water would add 102 mg/L sulfate but only 26 mg/L Mg++. Doesn't seem like much compared to the potential from the grains them selves.

That said, it is the same as with anything else. If you like the effects of fenugreek on your beer you should add fenugreek. If you like what extra magnesium does to your beer then add it. Determine this by tasting neutral beer, or the beer in question, with increasing increments of epsom salts added. Note that epsom salts are giving you 1) the sour bitterness of magnesium and 2) the dry hops bitterness enhancement of sulfate. It might be better to use magnesium chloride in order to discover the effects of Mg++ but as the question is as to whether you should add epsom salts or not I guess the test with epsom salts makes most sense.

I really appreciate you both taking the time to help me out and give me some tips and reassurance. I'm looking forward to tasting a homebrew after I get my mash pH in check.

One note on adding magnesium to your brewing water. It is critically important that you know what the starting magnesium content of the water is before adding additional magnesium. An old brewer's adage warning brewers to NEVER add magnesium to their brewing liquor can be found in the following discussion.

While AJ and I were assisting with the Water book, Colin Kaminski commented that he often adds magnesium to his brewing liquor. In talking with his fellow professional brewers, some warned that they had tried adding magnesium and it totally ruined their beers. With a bit more investigation, Colin found that their water already had high magnesium content and there was no need to add more. The recommended upper limit for magnesium in brewing water is around 40 ppm and above that the beer flavor is severely affected. Apparently those brewers had exceeded that level with their magnesium additions.

I recommend staying well below that 40 ppm limit. There are virtually no waters from reputed brewing centers that have magnesium that high. Only Burton water can be at that level.