Bru'n water adjustments for a porter

[CadiBrewer]

I'm trying to improve my water knowledge and move beyond the wonderful primer. I'm going to be brewing a 10 gallon porter recipe with the following grain bill:
Pale ale malt - 13lb 1oz
Brown malt - 2lb 12 oz - 150l
Crystal 75 - 1lb 13 oz
Chocolate - 1lb 6 oz 450l

I will be using 100% RO water and building from that. I chose the black balanced profile in Bru'n Water and built it as close as I could. Does this look like a reasonable starting point to brew the first time and then adjust to taste with subsequent batches? I should point out that I don't have a PH meter yet, so I'm going with the Bru'n Water numbers blindly until I buy a meter. I entered the PH of my RO water as 7 on the sparge acidification page because I don't have a meter to test it with. Is that a reasonable assumption?

 

[Hopper5000]

I can not comment on all of your questions. However, when I first started doing additions I used quite a bit of epsom salts as you have in this brew. Mine was a pale ale and it turned out that I have quite a minerally taste in my beer. I never put more than about 2 grams of ES in there because of this. I mostly put them in there to give the yeast a bit of magnesium, although malts/grains provide enough for the yeast.

You also want to be careful with your alkaline producing salts too. You don't want to raise your pH up too high because that can cause astringency to be extracted in the mash. Generally it's better to be lower than higher because of this, but again you don't want to be too low or enzymes will begin to get denatured.

I think a lot of people will leave out these additions, take a pH reading about 10min in, and then adjust with the calculator if it is way off.

I find Bru'n Water's calculator to do pretty well with pH estimation for most beers but it can be off on the darker ones. This is for my water profile (which is pretty soft) which is my municipal water and not RO water. I have done a few RIS's where the predicted pH was something like 4.8 and I didn't add any alkaline agents and it ended up being about 5.3. I have no idea why this happens and theoretically it shouldn't but it does. In essence I would maybe go with maybe half as much pickeling lime but others can chime in and correct me.

As for the RO sparge water I believe that RO water is more like 5.5 or 6 pH vs 7. If you are ballparking I would go with 7.

Like yourself I was using BnW without a pH meter for a few brews but I decided that I should get a meter because I didn't want to accidentally mess up a batch of beer which I did one time.

 

[mabrungard]

Those adjustments look fine, excepting that your estimated mash pH is still fairly low at 5.2. I would target at least 5.4 in a darker style like a Porter to help avoid a thin beer and to help round and deepen the roast character. In the case of darker styles, low pH actually helps present a dryer and more acrid roast flavor. A low pH is OK for a dry stout, but not a porter.

Like Hopper, I also tend to reserve my alkalinity mineral additions until I have proof from my pH meter that they are needed. I brew with RO water too. I have yet to find a case with my brewing where the Bru'n Water recommended lime addition didn't need to be added. My brown ale needed lime and it ended up within being only 0.01 units off the prediction after the lime was added. My apologies to Hopper for his results since they don't seem to be typical.

To hedge your bets, I would remember the 2.3 g lime addition gives you a 5.2 mash pH. I would then also revisit the lime addition needed to bring the pH to 5.4. At least then you would have an idea of how much more it will take to boost the pH that little bit.

At the proposed 8 ppm concentration, the magnesium content will not be perceptible and it will not be a problem. In the case of a porter, its debatable whether the Mg is needed at all. It could be left out without much detriment. I tend to always add a minimal amount of magnesium to my brewing water via epsom salts just to add nuance. The proposed level certainly won't create a minerally taste in the beer.

As you would see if you played with the water pH setting on the sparge acidification sheet, water pH has a very small effect on the amount of acid that you will ultimately add. So the assumption of a pH of 7 should be OK, but lower is probably more accurate. I note that there is a decent dose of acid in the sparging water. Is the alkalinity value on the sparge acidification sheet set to a low value that would be typical for RO water? You don't want to over acidify the water. RO water typically needs little or no acidification since its alkalinity is already low.

Lookin' good. Enjoy!

 

[Hopper5000]

Martin,

I wasn't trying to say your sheet is off I apologize. You have put out a valuable resource for the brewing community and myself and I have valued it greatly.

I was just speaking from personal experience with the sheet and darker beers like RIS's. I have only made 1 or 2 since I started using the sheet and even with a low bicarbonate level (27ppm) for some reason without adding a lot of alkalinity through brewing salts I managed to be within an acceptable mash pH range. I will continue to monitor this.

 

[CadiBrewer]

Thanks Hopper and Martin for the help, and especially to Martin for the spreadsheet.

To hedge your bets, I would remember the 2.3 g lime addition gives you a 5.2 mash pH. I would then also revisit the lime addition needed to bring the pH to 5.4. At least then you would have an idea of how much more it will take to boost the pH that little bit.

I upped the pickling lime to bring the mash PH to 5.4. Do the additions still look okay? I'll be getting a PH meter sometime in the next month or so, so I won't be flying blind for too much longer.

As you would see if you played with the water pH setting on the sparge acidification sheet, water pH has a very small effect on the amount of acid that you will ultimately add. So the assumption of a pH of 7 should be OK, but lower is probably more accurate. I note that there is a decent dose of acid in the sparging water. Is the alkalinity value on the sparge acidification sheet set to a low value that would be typical for RO water? You don't want to over acidify the water. RO water typically needs little or no acidification since its alkalinity is already low.

I entered 13 for the alkalinity value on the sparge acidification sheet. I pulled that value from the water adjustment sheet under the RO dilution values. Is that a bad assumption? In the above adjustments, I lowered the PH of the RO water to 6 from 7 and it dropped the acid addition to 3.8 ml.

Those adjustments look fine, excepting that your estimated mash pH is still fairly low at 5.2. I would target at least 5.4 in a darker style like a Porter to help avoid a thin beer and to help round and deepen the roast character. In the case of darker styles, low pH actually helps present a dryer and more acrid roast flavor. A low pH is OK for a dry stout, but not a porter.

That now makes sense to me because I've brewed two dry Irish stouts in the past two months and both have come out fuller bodied, less acrid, and less sour than I was shooting for. So next time I'll shoot for 5.2 for that mash PH. Is 5.2 a good number for a dry stout? Anything else to consider water-wise for getting closer to the flavor profile of that dry stout?

Thanks again for the help.

 

[CadiBrewer]

Bump

 

[mabrungard]

Those additions appear reasonable. I was surprised with the bicarbonate level, but this is a very dark grist. So its probably needed. I would be surprised that you would need to bump the bicarbonate to the higher level to keep the pH from dropping too far. I would just plan on using the initial 2.3 g lime amount and go with it. If you have a pH meter, then you could assess if the additional amount is needed.

Using the 13 ppm alkalinity for the RO water is a reasonable assumption. That should help avoid overacidifying your sparging water. Since the alkalinity is already low with RO water, I don't acidify that water for my sparging use. You can acidify if you want, but its not necessary. As you can see, its a small amount of that weak acid.