Using AJ's water primer for a stout w/ hard tap water

[MagicMatt]

Hi all!

I didn't want to plug up the Primer thread with questions that go beyond the scope of those instructions (although I don't think this isn't too far off), but in short, when brewing a stout is it OK to mash with 100% tap water (to keep pH in check), and then sparge with 100% distilled water to dilute a bit?

More Info:
I have somewhat hard water (alkalinity 148 ppm CaCO3). I've been using AJ's Primer (which I am ever so grateful for!) with most of my beers, but now I'm looking to clean it up around the edges. I just got a pH meter, so I'll be using that for the first time this weekend for an oatmeal milk stout.

I usually dilute my water with distilled at a ratio of 5:1 (to get my alkalinity below 35ppm as per the primer). After putting the info for this next beer into the BrewersFriend mash chemistry calculator, I'm worried that I cannot dilute my water as I usually do as the calculated mash pH is 5.48 with no dilution.

So my question is can I mash with 100% tap water, and use 100% distilled in the sparge?

Beersmith calls for 3.75 gallons for mash, 1.5 gallon mashout, and 3.15 gallons sparge. Therefore, if I do use only tap for mashing and only distilled for mashout/sparging, it will effectively only dilute my tap water into a 11/9 ratio (distilled/tap). I feel like this might not be enough as per the primer, and was wondering what kind of effect it would have on the resulting beer. (I'm sure it'll be drinkable, but I'd like to understand a bit more).

Thanks for your help!
Cheers

Edit: Attached a screenshot of what BrewersFriend says my resulting beer profile will look like with 100% tap for mash, 100% distilled for sparge, and adding 3.5g of calcium chloride. What else can I do? Some gypsum?

 

[ajdelange]

I didn't want to plug up the Primer thread with questions that go beyond the scope of those instructions

We can only wish that all were as considerate as you.

...(although I don't think this isn't too far off), but in short, when brewing a stout is it OK to mash with 100% tap water (to keep pH in check), and then sparge with 100% distilled water to dilute a bit?

Yes, that would work in some cases that is, cases where a lot of alkalinity is required but those cases are fairly rare. Even with RO water pH tends to stay above 5.2 up to about 20% roast grain addition.

More Info:
I have somewhat hard water (alkalinity 148 ppm CaCO3). I've been using AJ's Primer (which I am ever so grateful for!) with most of my beers, but now I'm looking to clean it up around the edges. I just got a pH meter, so I'll be using that for the first time this weekend for an oatmeal milk stout.

I usually dilute my water with distilled at a ratio of 5:1 (to get my alkalinity below 35ppm as per the primer). After putting the info for this next beer into the BrewersFriend mash chemistry calculator, I'm worried that I cannot dilute my water as I usually do as the calculated mash pH is 5.48 with no dilution.

As I noted above you could, conceptually, do this but I am skeptical that your mash will go as low 5.48 with water of 148 ppm alkalinity and a nominal charge of roast grain.

So my question is can I mash with 100% tap water, and use 100% distilled in the sparge?

As you have a pH meter why not try it on a test mash of about 1 lb of grist and see?

 

[MagicMatt]

We can only wish that all were as considerate as you.

Yes, that would work in some cases that is, cases where a lot of alkalinity is required but those cases are fairly rare. Even with RO water pH tends to stay above 5.2 up to about 20% roast grain addition.

As I noted above you could, conceptually, do this but I am skeptical that your mash will go as low 5.48 with water of 148 ppm alkalinity and a nominal charge of roast grain.

As you have a pH meter why not try it on a test mash of about 1 lb of grist and see?

Thanks for the reply (from the man himself no less!!). Unfortunately I only have my next grainbill on hand, so no extra grain to do a test mash at this point. But that is a great idea and I think in the future I'll always get a bit extra just for this reason.

I used the calculator to recalculate using my normal dilution ratio, and it only reports the mash dropping to 5.36 pH. I guess I thought that diluting by 500% would lower the pH more than it seems to do (at least according to the calculator).

I kind of asked this in the Primer thread already (oops), but diluting 5:1 as usual and then adding 2g of baking soda to the mash would seem to raise the pH to 5.5 (see attachment), which from what I'm reading is pretty much where I want to be for a stout (pH measured at room temp). I'm assuming 2g is not much in terms of negative effect it could impart, correct? Is there such an upper limit that one would want to stay beneath?

One last thing, I usually try to increase my salt additions to get those "low" numbers (Ca and SO4) until I get a "normal" result. What's your take on this in terms of importance or significance? I read your recent sticky regarding the Cl/SO4 "ratio" and how it is usually over-emphasized, but does that mean I shouldn't worry at all about getting these numbers more "normal"? It always seems to be these same 2 numbers that are low, and I usually compensate by adding a touch more calcium chloride and/or gypsum to the boil.

Thanks so much for your help!

 

[MagicMatt]

Actually, I just checked the BrewersFriend calculator again, and I had accidentally left the "Use different water sources for mash and sparge" checkbox checked (in addition to the "Blend Waters" checkbox). I set the percentage to 80%.

So what exactly does this mean by having both checked? Does it mean to blend my mash water 80% DI, 20% tap, then use only DI (water source B) to sparge?

If so, I think I'd rather instead use my usual method of diluting my total water, not just mash. Readjusting the calculator, I now only get a predicted mash pH of 5.41 with a 2g sodium bicarbonate addition.

But then again, you said the calculator was probably off anyway. I guess I'll just check the pH after about 10 minutes before adding the baking soda, and only add it if I need it.

 

[ajdelange]

I can't predict with certainty (any more than BrewersFriend or any other calculator can) but the liklihood is that mash pH will be about 5.7 with this level of alkalinity and a modest calcium addition. With DI water it would drop to about 5.5. Thus you will probably not need bicarbonate. Witholding it until you have verified you need it is wise.

 

[MagicMatt]

I can't predict with certainty (any more than BrewersFriend or any other calculator can) but the liklihood is that mash pH will be about 5.7 with this level of alkalinity and a modest calcium addition. With DI water it would drop to about 5.5. Thus you will probably not need bicarbonate. Witholding it until you have verified you need it is wise.

So I brewed yesterday, and I used 50% tap, 50% distilled. My tap water according to Ward Labs is:

pH: 9.2
Na: 30
K: 3
Ca: 48
Mg: 12
SO4-S: 17
Cl: 38
CO3: 25
Bicarbonate, HCO3: 130
Total Alkalinity, CaCO3: 148
Total Hardness, CaCO3: 170

I added my grain (Yooper's Oatmeal Stout) to 3.75 gallons of the diluted water. At 10 minutes I measured pH at 5.36. I went to the kitchen to grab some baking soda to find we were out. Oops. But I checked the pH again at 30 minutes and it was at 5.41.

I'll go with the latter number since it was likely more representative, but that seems a bit off from what you suggested it would be with just pure DI (5.5), much less diluted as it were.

This leads me to believe that either my pH measurements need help, or my water isn't what I think it is. I plan to get another water test asap. Other than that, I calibrated my Hanna pHep (two point) just before using to measure the mash sample. After reading the sample I checked the meter in the calibration solutions and it registered 4.04 and 7.02.

I did unfortunately get a few small hull fragments in the sample, as the mash was very thick and it was hard to even get the small amount I did. It was like thick oatmeal.

Anyway, the brew was a success nonetheless and I overshot my OG by about 6 points, so my mash efficiency seems to have improved slightly. Thanks for your help, and feel free to drop any other tidbits you may feel relevant.

Cheers.

 

[ajdelange]

I'll go with the latter number since it was likely more representative,

Yes, you have to wait for equilibrium to be approached.

.. but that seems a bit off from what you suggested it would be with just pure DI (5.5), much less diluted as it were.

This leads me to believe that either my pH measurements need help,

I wouldn't assume that. Your post measurement buffer check indicates that the pH readings are probably valid. The reason my estimate is lower is that either your base malt has less buffering capacity than does the base malt I used in my calculations or that your roast malt has more than the malt I used in my calculations or both.

..or my water isn't what I think it is.

Water's do change and there are some problems with your Ward Labs report as discussed elsewhere but that isn't going to change the conclusion in the last paragraph.

I did unfortunately get a few small hull fragments in the sample, as the mash was very thick and it was hard to even get the small amount I did. It was like thick oatmeal.

That's not something that you need to worry about.

 

[MagicMatt]

Hey AJ, I know it's been a while since this thread, but I'm about to brew this stout again and wanted to home in on the water profile a bit more. I've brewed it once more since my last post on this thread. Don't get me wrong, it tasted great, but my pH was still off from what I was expecting. You mentioned you didn't think it should go much below 5.5 with just DI, but here's my notes from the last brew of this beer:

Used 100% tap water (15qt) for mash, 100% distilled (21qt) for mash-out/sparge. Forgot to add Campden tablet to mash! DOH!!!!

Ambient temp 60°F. Strike water was 169°F. Dough in at 167°F.
Mash @ 10min was 155°F; @ 30min was 154°F.
pH @ 20min was 5.35.
Final running was 4.2 Brix (1.016 SG) and 5.4 ph.
Pre-boil SG was 11.8 Brix (1.046 SG).
OG 1.056.

So as you can see, my pH got way lower than I expected. I've since submitted my own sample to Ward Labs (was using the LHBS's report previously) but it's not much different:

9.1 pH
264 TDS
5.0/5.1 Cations/Anions

26 Na
3 K
53 Ca
13 Mg
187 Hardness CaCO3
18 SO4-S
27 Cl
10.7 CO3
166 HCO3
151 Alkalinity CaCO3


Using the grain bill section on BrewersFriend tell me my mash should be 5.6, which is close to what I'm aiming for. If I switch to using the color, weight, and % roasted malts, it drops to 5.2. From my experience the last 2 times, I'm somewhere in the middle.

Grain bill is:
7 lbs Maris Otter (3L)
1 lb Flaked Oats (1L)
12 oz Victory (25L)
10 oz Pale Chocolate (250L)
8 oz Flaked Barley (2L)
8 oz Black Barley (500L)
8 oz Crystal 80 (80L)
2 oz Chocolate (350L)

I suppose I just have to work with what I'm getting, and so now I'm wondering about a baking soda addition to the mash to up the HCO3 and pH a bit. Is 6 grams unreasonable? Adding 6g baking soda, 5.5g CaCl, and 2g epsom yields:

 

[ajdelange]

Using the grain bill section on BrewersFriend tell me my mash should be 5.6, which is close to what I'm aiming for. If I switch to using the color, weight, and % roasted malts, it drops to 5.2. From my experience the last 2 times, I'm somewhere in the middle.

I get 5.52 as the estimated pH (using the amounts of the grains you specified, the water properties you specified and the DI mash pH and buffering capacities I or others have measured or something that has been measured that is close to what you specified). I assumed Crisp Maris Otter. If I use Muntons the estimate goes up to 5.61.

If you are getting 5.35 with this grain bill that means that either my cumulative estimates of malt acidity (with Crisp) are shy 50 mEq or your malts are more acidic than my models by 50 mEq or some of each. To get to pH 5.5, assuming the buffering capacity of my models is the same as your grains (even if the DI mash pH's are not) would require you to absorb the 50 mEq of protons.

I suppose I just have to work with what I'm getting, and so now I'm wondering about a baking soda addition to the mash to up the HCO3 and pH a bit. Is 6 grams unreasonable? Adding 6g baking soda, 5.5g CaCl, and 2g epsom yields:

Baking soda is a candidate. Baking soda's equivalent weight is 23 + 61 so you will need 50/84 = 4.2 grams.

Personally I would have no problem with a stout that finished the mash at 5.4 IOW I don't buy the stout should be mashed at higher pH argument but if you do or if you want to see how a stout mashed higher tastes relative to the last one you did then by all means shoot for a higher pH. Because we can't know whether the discrepancy is from your grains or the models or partly from each I would be inclined to go with half that amount of bicarbonate to see what happens.

 

[MagicMatt]

Thanks for the quick response! Yes, it is Crisp MO, I bought a sack about 6 months ago and just finishing it up now.

I neglected to mention that only the baking soda addition was added to the mash; the CaCl and Epsom I mentioned were slated for the boil. Not sure if that changes anything with your equations, as I know those tend to lower the pH if added to the mash which is why I reserved them for the boil.

Thanks again for your help! I think I'll go with your recommendation and do maybe 2.5 grams and see how it goes!