Two water reports and I'm a bit confused on dark beers & bicarbonate

I've now done two separate ward lab reports. They are (I think) largely the same, though they are seasonally separate (July/Feb), both drawn off my hot water since I use that for brewing currently and between that time I did end up replacing the water heater. Not sure that made much difference, but still.

My main confusion is this - is there a point that for dark beers you can have too much Bicarbonate, but seemingly not have a negative effect on lighter beers?

First report (July):
pH 7.4
Total Dissolved Solids (TDS) Est, ppm 311
Electrical Conductivity, mmho/cm 0.52
Cations / Anions, me/L 5.3 / 5.7

ppm
Sodium, Na 11
Potassium, K < 1
Calcium, Ca 63
Magnesium, Mg 19
Total Hardness, CaCO3 237
Nitrate, NO3-N 0.1 (SAFE)
Sulfate, SO4-S 10
Chloride, Cl 20
Carbonate, CO3 < 1.0
Bicarbonate, HCO3 274
Total Alkalinity, CaCO3 225
Total Phosphorus, P < 0.01
Total Iron, Fe 0.31
​

The second one from winter is similar, but my PH has jumped up along with my TDS going up a bit.

Second Report (Feb)
pH 8.0
Total Dissolved Solids (TDS) Est, ppm 334
Electrical Conductivity, mmho/cm 0.56
Cations / Anions, me/L 6.0 / 6.3

ppm
Sodium, Na 20
Potassium, K 1
Calcium, Ca 68
Magnesium, Mg 20
Total Hardness, CaCO3 253
Nitrate, NO3-N < 0.1 (SAFE)
Sulfate, SO4-S 9
Chloride, Cl 37
Carbonate, CO3 < 1.0
Bicarbonate, HCO3 287
Total Alkalinity, CaCO3 237
Total Phosphorus, P < 0.01
Total Iron, Fe 0.19​

This is well water, not city water, so I'm guessing seasonal shifts in my well account for most of the change. I do acid treat the water with Phosphoric Acid to get down to the proper PH range, but I'll be honest I'm testing with strips and it doesn't seem to match up how the spreadsheets think it should, I've bought a meter (showed up yesterday) so eventually here I'll have a good idea how it's working.

The reason I'm confused is this, I read that higher Bicarbonate is 'good' for dark beers. Yet it's the dark beers I'm actually struggling with more. They come out astringent. Lighter colored beers (Edwort's Centennial Blonde for example) with less crystal/roasted malts generally end up being better beers for me then when I brew up a darker beer like an Irish Stout. The darker beers, at lower abv (<5%) often have this astringent/aggressive taste, particularly in the finish that's not exactly pleasant. If I head well into the higher ABV range (>9%) there's so much malt backbone I think this unpleasantness just isn't detectable or the residual sweetness from higher finishing gravity masks it. I've found I also do better with sweet/milk stouts then dry stouts, probably for the same reason.

It also happens to beers that approach darker colors (usually with a bit of roast barley), such an Irish Reds which while not as bad as the dark beers, have this hint of dry astringency to them in the finish.

So I guess is there a point where the level of bicarbonate becomes too high for darker styles while seemingly producing acceptable tasting lighter colored beers? Or am I missing something fundamental here?

It seems the conventional wisdom is with 200ppm+ of Bicarbonate that darker styles should be turning out better then lighter ones, yet for some reason everyone (judges, my wife, friends) are happier with the tastes of the lighter style beers from this water with minimal (.5ml/gal Phosphoric acid only for PH) treatments. I've gotten multiple scoresheets back citing 'mild astrigency' which I'm guessing is a water problem in my case. Admittedly the lighter beers are not Pilsner levels of light, but still they are by no means 'dark beers'.

I'm doing BIAB, so it's full volume mashes, no sparge. So for smaller beers it's a very 'watery' mash. I'm probably going to try dillution with distilled water on a batch soon and I'm going be doing some PH testing on my finished beers now that I have an actual meter to try to get some idea where the ph of them has ended up to try to track down this problem, but I'd be interested any advice anyone here has.

 

Your water (both tests) looks pretty reasonable and similar to what I use here. Astringency would typically come from the mash pH being too HIGH; in darker beers, the dark roasted malts usually result in more acidity & lower pH, exactly the opposite of where you would expect astringency to occur. No, something else must be going on..... Aha! I think I *might* have a valid theory for you:

You say you are brewing in a bag (BIAB), no sparge, etc. What has happened to me in the past with BIAB when I first started out is that I experienced astringency due to chunks of grains and husks being boiled for the full 60 minutes or longer. This is not good -- it's not good to boil grains like this for that long. When I figured this out, I figured the best way to filter this junk out would be to place the bag into a colander, then pour the entire sweet wort through the bag and colander to filter most of that junk out.... essentially fly sparging by hand without a sparge arm. It's a major pain in the butt, but it actually resolved the issue. An easier way to accomplish the same thing would be to pour your wort through a very fine mesh bag or paint strainer or something to get any chunks of grains and husks out of there before you boil. Very important. My guess is your grain bag has a mesh that is too wide allowing a lot of this to be boiled in your wort. Keep that junk out of there, and the problem may go away. Dark roasted grains are more susceptible to this since they tend to disintegrate and turn into powder when crushed, more than pale malts do.

That's my theory based on what few facts were given above. I might be wrong but take a look and see what you think. Hope it helps in some way.

EDIT: Actually, your alkalinity is about double what mine is here. You might just want to blend your water 50/50 with distilled from now on, or even more distilled than that, 75/25 or whatever. Dark vs. light styles though shouldn't matter -- you'd be picking this up in every style if it were a serious issue. Doesn't make much sense otherwise if my grain bag idea above isn't valid.

 

Your water is very alkaline: 225 (4.5 mEq/L) in the one report and to 237 (4.76 mEq/L) in the other. You are going to have to add 90% of those numbers in acid (well over 4 mEq/L) in order to remove the alkalinity from the water. If you do that either by calculation or by just adding acid until the pH of the water reaches mash pH you have then set your water proton deficit (alkalinity) to 0 and if you are using a lot of high kilned malt mash pH will be too low. It is hard to comment further here as I don't know in any detail what you are doing. I would consider cutting 4:1 with RO water in order to get alkalinity below 1 mEq/L.

 

That water is well over the limit for alkalinity, in my opinion. I'm surprised with the OP's perception that the paler beers are acceptable, but this may be due to being so far over the limit and being unable to discern some flavors. I agree with AJ that reducing the alkalinity to less than 1 mEq/L via dilution is desirable for pale beer brewing. The amount of additional acid is less likely to affect the resulting beers. However for the darker styles, I find that you would only want to dilute to about 1 to 2 mEq/L in order to have an adequate, but low alkalinity to neutralize the roast acidity.

 

Thanks guys that's what I expected would be the case, I'm going to brew up a batch blended down with distilled and if that helps look at getting an RO filter for my brewing.

I can't explain the lighter beers either that's been my real mystery in this.

 

I don't think this is the case, I've never seen any grain get through the voile bag I was using and my new 400 micron basket I used in the last few beers seems to not let anything through either.

I'm also not crushing as aggressively as some folks recommend for BIAB, my crush is fairly course because it helps me recirculate easier (RIMs).

 

Yeah, it's just the alkalinity issue. Treat with acid or dilute as described previously and you should be fine.

 

Well, I've finally got a test batch with dilution on tap. Did something smaller because in most cases my bigger beers seemed to be less impacted by the flavor I've been tasting. Though in a less than ideal test it's not a dark beer, it's pretty pale (8 SRM ) but fairly low gravity.

Bought a Milwaukee PH meter too, so I have actual PH readings rather then squinting at strips.

Ended up diluting my well water with 50% distilled water and then adding in a bit of phosphoric acid and gypsum.

Final water profile looked like this:

Calcium 126 ppm
Magnesium 10ppm
Sodium 10ppm
Sulfate 162ppm
Chloride 61ppm
Bicarbonate 27ppm

Mash PH was pretty much on target with BrunWater's prediction (it said 5.4, my PH meter said 5.5, I say close enough.)

I've withheld highly kilned grains (Gordon strong style) before but since that didn't have an effect everything went in at once this time. 20lbs Pilsen, 10oz Special B, 8oz Carapils. Hopped with Summit for bittering and Styrian Goldings late additions. Fermented out with Spencer Trappist yeast.

Resulting beer is fantastic, great belgian character and honestly the first of my beers that has a distinctive malt profile to it. Previously anything that should be malty ended up more muddy and this has a soft pleasant graininess. No sharpness, no astringency, nice light hoppy character (Pleasantly surprisingly for a ~17-20 IBU beer)

Couldn't be happier with it, I'm guessing it's time to look into an RO filter for brewing because honestly I don't think I want to keep trucking home 5 gallons of water everytime I brew.

Thanks for all the help!