Adjusting mash ph in a stout???

I'm about to undertake my first stout, a RIS. I've been AG brewing for a while, 16 batches I think. I've done lots of lighter in color ales, a couple of browns so I've not had to worry about mash ph as I've not had a problem with conversion, hop utilization in the boil, etc.

BUT I understand the amount of roasted grain I'm about to use can adversely effect mash ph. In preparation for brewing this bier I purchased ph paper, calcium chloride, and calcium carbonate.

Can someone share or point me to the best process for adjusting a mash ph?

Schlante,
Phillip

MVKTR2 said:

I'm about to undertake my first stout, a RIS.

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Phillip,

Do you have a water report for your water so we can get an idea what you are starting with?

Yes, the large amount of roasted grain in a stout does lower the mash pH. But they actually lower it less than many brewers think. In fact roasted grains have less pH lowering potential per unit of color than crystal or base malts. This means that your water doesn’t have to be all that high in alkalinity.

In fact, if you listen to the BN CanYouBrewIt episode with Stone brewing, they say that they brew all their beers with water that has a harness of ~100 ppm CaCO3. I expect the residual alkaliniy of that water to be around 70 ppm CaCO3. Residual alkalinity (RA) is a measure of how much the water balances the acidity of the malt. More alkalinity -> higher mash pH. In the case of Stone they even brew their RIS with that water. I’m not saying that we should now start brewing Stounts and RISs with moderately soft water but I’m just bringing this as an example of how soft a water one can successfully use for a RIS.

Do you already have a recipe in mind. The type of base malt, percentage of crystal malt and percentage of roasted malts can help in making an educated guess of the residual alkalinity that you should be targeting.

Kai

Kai, I've got no water report, I know I need to get one... but as yet I'm not using my own water! Long story short, I need to buy a new filter. I'm using 'Kentwood' brand bottled drinking water. This is from Kentwood springs in Louisiana. Hadn't thought about it now but I could search their website for a water profile or email them.

The recipe is as follows:
4 Gal. Batch
10.00 British Two-row Pale (MO)
1.00 British Crystal 135-165L (Homemade to a dark lovibond)
0.75 German Roasted Barley
0.25 American Black Patent
0.38 Pale Chocolate
0.75 Molasses

Suppose all you need is the grain bill?

I forget the general rule, hard water is good for dark biers & soft for light, correct? My local water, moved this summer, is slightly hard where as my previous local water was slightly soft.

Thanks,
Phillip

Hey, for $16 you can test your tap water. If it's decent, you can stop wasting money on bottled water.

I forget the general rule, hard water is good for dark biers & soft for light, correct?

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For the most part...but it isn't always necessarily the case.

FWIW, I have extremely alkaline water (300+ ppm CaCO3) and have made a couple of really nice german "light" beers. Munich helles and kolsch come out great and I'm just about to keg a pils that tasted fantastic from the sample. I generally don't bother testing my PH (something I've been meaning to do just to understand the science), but I've never had a problem. I do use 5.2 buffer on the lighter styles FWIW.

edit: Definitely agree that you should get your water tested whenever possible. Being the nerd I am, it's really fun knowing and being able to control every variable possible...and water is certainly an important one that is often overlooked.

I found a water report here: http://www.kentwoodsprings.com/files/nonbrand/waterqualityreports/spring_water_quality_report.pdf

But it doesn’t list much that is of interest for us brewers. The only useful items are:

- sulfate 0 – 11
- total dissolved solids 13 – 200

From that I judge that your water is moderately hard.

Looking at the grist and using some of the malt acidity data that I have I would expect that you get a distilled water mash pH of about 4.7. Most of the drop comes from the crystal malt that you are using. There is nothing wrong with that. But you’ll need quite a bit of residual alkalinity to bring that pH into the low 5s.

At this point I suggest bumping your alkalinity by ~250 ppm CaCO3. This takes a bit of baking soda and chalk. To keep the water from getting too hard, I recommend adding all the salts to the mash and none to the sparge. It’s the mash where you need their acid neutralizing power anyway.

For your 12lb of grist I suggest about 4.5g baking soda and 6.0g chalk (CaCO3).

Do you have a means to test mash pH?

As for getting a water report, I started playing around with a $5 GH/KH test kit for aquarium water. Its tests general Harness (GH), which is a measure of calcium and magnesium, and carbonate hardness (KH) which is alkalinity. From these two measurements one can make a fairly good guess at the residual alkalinity. I think this may beat sending samples to Ward labs for the more “casual” brewers. But even if you send a sample to ward labs you can still use this test kit to check if your water is changing and if it would make sense to get the water analyzed again.

Kai

Thanks Kai, Charlos, Bobby

I appreciate you finding that water report for me, and of course giving a suggested correction based on my info. Very useful! My follow-up question would be, what would happen if I just brewed with the water the way it is? I ask this not because I'm ignoring what's needed, but because I want a baseline difference and maybe it'll help anyone else who runs across this thread. Oh yea to answer your questions, yea I've got ph test strips and CaCO3 etc.

Bobby I'm familiar with Ward labs, and will get around to testing my water one day. I found the advice I got from someone when I was first looking into AG brewing to be quite helpful... 'just brew it'. The idea being don't worry about it till you know you have a problem. I kind of figure I have a bit of a problem with my water as limestone fields run all through this part of the country, including volkswagon sized rocks in my front yard It's just not a priority at the moment as I'll need to invest in a new carbon filter first!

Sometimes I'm very anal about all aspects of my brew, others not so much. This happens to be one I'm trying to get lots of input on so I don't mess up a promising brew! Again thanks and if someone could sound off in the differences between brewing something like this with vs without water adjustments I'd appreciate it.

Schlante,
Phillip

MVKTR2 said:

I kind of figure I have a bit of a problem with my water as limestone fields run all through this part of the country, including volkswagon sized rocks in my front yard It's just not a priority at the moment as I'll need to invest in a new carbon filter first!

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As a rock climber I'd love to have one of those in my yard

If you don't add the salts, your grist may pull down the mash pH too much which lowers the effectiveness of the enzymes. Here is a primer on what pH does in brewing: http://braukaiser.com/wiki/index.php?title=How_pH_affects_brewing . Don't let it scare you though.

You may just dough in w/o the salts and test pH. If it is below 5, throw in the salts, mix and test again. Some brewers reported an acrid taste in stouts that were brewed with water that's too soft.

Kai

Kaiser said:

As a rock climber I'd love to have one of those in my yard

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As some are buried in the soil on the south edge of the property and I can't use the mower there, have to have it bush-hogged, they're a bit of a niusance. Though many people to make good use of them in landscaping.

You may just dough in w/o the salts and test pH. If it is below 5, throw in the salts, mix and test again. Some brewers reported an acrid taste in stouts that were brewed with water that's too soft.

Kai

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I'm glad to hear you say this, it's exactly what I was hoping to do. Thanks again.

Schlante,
Phillip