efficiently measuring mash pH

[murphyslaw]

I'm trying to improve my process and a big part of that is measuring. The mash seems like an important part of my process that is ripe for improvement so I've been reading up on water chemistry and the mash process. I had not appreciated the importance of pH and I'm trying to implement what I've learned. From what I've gathered, I need to hit a particular pH target range during the mash and should also make sure not to drain beyond when the runnings hit a particular pH and OG to avoid extracing tannins or whatever.

But taking all these measurements seems like a real PITA, especially since I've read that pH readings should be taken at room temp. Last weekend, after letting the mash sit for 5 minutes, I pulled a sample, cooled it and tested it. It was 4.6. So I added chalk and waited another five minutes, pulled a sample, tested, and it was still a little low (maybe 5.0? I don't know if I'm color blind or what but I'm not very good at matching colors). So I added another 1/2 tsp of chalk. By that point I was probably 20 minutes into my mash and figured it should be close enough. But that's a lot of mash time at the wrong pH.

Then when it comes time to collect the runnings, do you just stop draining when the flow slows down and take 5+ minutes to check the pH and gravity? Then if its still ok, drain again, stop again, check again? I typically collect three separate runnings so this seems really inefficient.

I'm wondering whether people who are mindful of the mash pH have any ideas on how to improve this process or whether they take all of these measurements.

 

[MrHadack]

Okay, let me see if I can offer some procedural advice that will get you going in the right direction.

First, buy a pH meter. A decent one doesn't cost too much, and will really save you some trouble. This is the one I use and it has been great.

Second, there are ways to make sure your mash will have the right pH before you start. This will save you from having to adjust it too much when the mash is actually taking place. There are spreadsheets available that will allow you to calculate what the mash pH will be before you do anything, based on the water you are using and the grains that will be included in the mash. One in particular has been extremely accurate for me over the years. You can download it here.

At first glance it will appear extremely complex, but don't be intimidated! It is easy to use once you understand it. If you use distilled or reverse osmosis water, you can tell it that, or you can enter the information about your tap water profile that can be obtained online. This information will have your water's pH, as well as parts-per-million (PPM) of calcium, magnesium, chlorides, sulfates, and so on. After that, you enter in the amounts and types of grain you are using (which can add acidity, so it is important). The spreadsheet will take all this information and calculate a predicted mash pH at room temperature.

If the predicted mash pH is too high or low, you can then use the spreadsheet to determine what you need to add, and in what quantities, to get it just right. For example, 0.2 grams of Gypsum per gallon of mash water. Once the spreadsheet has the predicted pH just right (let's say 5.4), then you just add the stuff to the water like it suggests, mash, and your pH will be right where it needs to be.

Using this technique, you'll know your mash pH before you even start the mash. I use it for every batch, and I'm typically exactly on target, or off by 0.1 (5.3 - 5.5 every time.)

Have a look at the spreadsheet and let me know if you have any questions. I'd be happy to send you a sample of one from a batch I recently made so you can get an idea of how to use it.

By the way, it will also include recommended treatments for the sparge water so you can stop worrying about tannin extraction.

 

[mdabbles]

Okay, let me see if I can offer some procedural advice that will get you going in the right direction.

First, buy a pH meter. A decent one doesn't cost too much, and will really save you some trouble. This is the one I use and it has been great.

Second, there are ways to make sure your mash will have the right pH before you start. This will save you from having to adjust it too much when the mash is actually taking place. There are spreadsheets available that will allow you to calculate what the mash pH will be before you do anything, based on the water you are using and the grains that will be included in the mash. One in particular has been extremely accurate for me over the years. You can download it here.

At first glance it will appear extremely complex, but don't be intimidated! It is easy to use once you understand it. If you use distilled or reverse osmosis water, you can tell it that, or you can enter the information about your tap water profile that can be obtained online. This information will have your water's pH, as well as parts-per-million (PPM) of calcium, magnesium, chlorides, sulfates, and so on. After that, you enter in the amounts and types of grain you are using (which can add acidity, so it is important). The spreadsheet will take all this information and calculate a predicted mash pH at room temperature.

If the predicted mash pH is too high or low, you can then use the spreadsheet to determine what you need to add, and in what quantities, to get it just right. For example, 0.2 grams of Gypsum per gallon of mash water. Once the spreadsheet has the predicted pH just right (let's say 5.4), then you just add the stuff to the water like it suggests, mash, and your pH will be right where it needs to be.

Using this technique, you'll know your mash pH before you even start the mash. I use it for every batch, and I'm typically exactly on target, or off by 0.1 (5.3 - 5.5 every time.)

Have a look at the spreadsheet and let me know if you have any questions. I'd be happy to send you a sample of one from a batch I recently made so you can get an idea of how to use it.

By the way, it will also include recommended treatments for the sparge water so you can stop worrying about tannin extraction.

Thank you, this is very helpful..

 

[MrHadack]

No problem! If you have questions using the sheet, let me know and I'll help you out.

 

[murphyslaw]

Thanks for the reply; very helpful.

I'll try that spreadsheet for my next brew. I had used the EZ Water Calculator but may not have done it right. And I'll definitely get that ph Meter which is a lot cheaper than most others I've found.

 

[Yooper]

Thanks for the reply; very helpful.

I'll try that spreadsheet for my next brew. I had used the EZ Water Calculator but may not have done it right. And I'll definitely get that ph Meter which is a lot cheaper than most others I've found.

Something else to keep in mind- don't use chalk! Chalk doesn't dissolve properly without extraneous effort (bubbling c02 through it) so if you ever need alkalinity use something like baking soda.

Still, I think your strips were way off. It would be extremely unusual to have a mash pH of 4.6 unless you used all black malt in the mash, even with RO water. I'd trust something like bru'nwater for a guestimate way before I'd accept that 4.6 pH.

If you post your recipe, and your water makeup, we could help you guestimate a probable mash pH in one of the spreadsheets if you'd like.

 

[runkelia]

This article helped me understand how to calculate how much wort you should collect without over sparging.

http://beerandwinejournal.com/batch-sparge-wort-collection/

 

[MrHadack]

And I'll definitely get that ph Meter which is a lot cheaper than most others I've found.

Don't forget a bottle of calibration solution. The 7, 4.01, or both. I think a 2 pack is available on Amazon.com for $14 and it is really worth having.

Another note on pH: like everything else with home brewing, RDWHAHB: If your pH is 5.6 when you measure it, don't fuss about it too much. That's definitely in the acceptable range.

 

[murphyslaw]

If you post your recipe, and your water makeup, we could help you guestimate a probable mash pH in one of the spreadsheets if you'd like.

Sure! Thanks!

6 lbs Wheat (Weyermann)
4 lbs Pilsner (Weyermann)
8 oz Rice Hulls
.75 oz hallertauer @30
.25 oz Hallertauer @ 15
Zest from 2 oranges @ 5 min
Wyeast Weihenstephan Weizen #3068

The target water profile I came up with based on Palmer's new water book was as follows:


Ca 50-100
Alkalinity 0-80
Sulfate - 0-50
Chloride 0 - 100
RA -50 (the book said -30 to 0, but the spreadsheet said -78 to -20 based on my target color of 3.6 SRM)


I used distilled water because I wanted to get this right and the information I got from the water company wasn't quite detailed enough. I actually used Palmer's spreadsheet, not the EZ Water Calculator, and as I look at this again I think I see my mistake--I entered the total water volume (strike plus sparge water) as the Mash Water Volume and probably should have included only the strike water.

So using a mash volume of 9 gallons, I came up with 3g of Calcium Chloride, 3g of Epsom Salt, 1g of Chalk, and 3ml of Lactic Acid. Palmer's spreadsheet predicted the following:

Ca-36
Mg - 9
Alkalinity as CaCO3- 29
Sodium - 0
Chloride - 42
Sulfate 34
RA - (-53)

But my strike water was about 13 quarts (1.25 qt/lb of grain) or about 3.25 gallons. So if I put that in as the Mash Volume....

Ca-99
Mg - 24
Alkalinity as CaCo3- 81
Sodium - 0
Chloride - 118
Sulfate 95
RA - (-148)

So that seems to explain why the pH would have crashed, right?

Using the Brun Water spreadsheet, it looks like I should have gone with 0.6 g/gallon of Epsom Salt (2g in strike water, 3.5g in sparge) and Calcium Chloride with 0.3 ml/gallon of lactic acid.

 

[Yooper]

No, you didn't have nearly enough acid to have such a low pH. Not 4.6 with only 3 ml of lactic acid- that doesn't seem possible at all. What is the predicted pH according to the EZ water or brunwater spreadsheet?

Next time, ditch the epsom salts (most beers aren't improve with magnesium and malt has plenty for yeast health) and chalk (doesn't work).

 

[MrHadack]

I'm getting the same results as Yooper. In fact, with your grain bill, 3.25 gallons distilled water, and the chem additions you used, I actually get a pH of 5.2! Of course, pH isn't the final word since you have some levels like Mg, Sulfate, and Chloride that are way too high.

So I think switching to a digital meter that you can calibrate will help, since pH strips can be a lot of interpretation. Also, like Yooper said, knowing what additions to use (and avoid) will help. I never use Chalk, Magnesium Chloride, and barely any Epsom Salt. Almost anything can be solved with the Lactic acid, Gypsum, Baking Soda, and Pickling Lime (though some people frown about that last one.) And as the sheet notes: baking soda, chalk, and lime are not for use in the sparge water. You want your sparge water to have a pH of under 6 (I shoot for 5.7) because pH is one of the most important factors when it comes to avoiding tannin extraction.

Oh-- one other note: I find the amount of lactic acid is drastically over-calculated; I always use half of what is recommended, stir, wait a few minutes, and then test again. You can always add more if needed.

 

[murphyslaw]

No, you didn't have nearly enough acid to have such a low pH. Not 4.6 with only 3 ml of lactic acid- that doesn't seem possible at all. What is the predicted pH according to the EZ water or brunwater spreadsheet?

Yeah, you're right. The EZ water spreadsheet predicts a pH of 5.61 with the additions I used. Brun gives me 5.2, like MrHadack said.

Next time, ditch the epsom salts (most beers aren't improve with magnesium and malt has plenty for yeast health) and chalk (doesn't work).

My goal was to increase the Ca up towards 50. I added the CaCl2 to gain try to bring the Ca up and then the epsom salt to get the SO4 to balance out the Cl2. I think I added the Chalk to get a little more Ca without having to add even more Mg. Is there a better way to increase the Ca without having to deal with the side effects of adding other elements?

So I think switching to a digital meter that you can calibrate will help, since pH strips can be a lot of interpretation. Also, like Yooper said, knowing what additions to use (and avoid) will help. I never use Chalk, Magnesium Chloride, and barely any Epsom Salt. Almost anything can be solved with the Lactic acid, Gypsum, Baking Soda, and Pickling Lime (though some people frown about that last one.) And as the sheet notes: baking soda, chalk, and lime are not for use in the sparge water. You want your sparge water to have a pH of under 6 (I shoot for 5.7) because pH is one of the most important factors when it comes to avoiding tannin extraction.

Oh-- one other note: I find the amount of lactic acid is drastically over-calculated; I always use half of what is recommended, stir, wait a few minutes, and then test again. You can always add more if needed.

Thanks for the tips. I ordered the pH meter and solutions this afternoon. I have no confidence in my use or interpretation of the test strips. You still need to cool down the sample to read the pH, right? That meter says it can adjust up to 140* but I've read elsewhere (IIRC it was in the pH meter buying guide here on HBT) that you should cool it to room temperature anyway.

 

[MrHadack]

You still need to cool down the sample to read the pH, right? That meter says it can adjust up to 140* but I've read elsewhere (IIRC it was in the pH meter buying guide here on HBT) that you should cool it to room temperature anyway.

Yes, always cool the sample. I asked the same question once before and this is what Martin Brungard (the spreadsheet creator and lord of water science) told me:

"Using any pH meter at a temperature much more than room temperature will speed its failure. Temperature compensation is a falsehood in brewing use since the meter is only correcting for 'its' reading variation with temperature. The mash chemistry and pH changes with temperature and the meter is not correcting for that. So you are kidding yourself by measuring pH at a mash temp."

As for the question about adding calcium without adding anything else:
No, not really. But what you can do is add calcium from sources that include other secondary sources that help accentuate certain aspects of your beer. If it's an IPA, add gypsum to get your Calcium up, because it will also increase Sulfate which help accentuate hop characteristics. If it is malty beer, Calcium Chloride would be a good pick since additional Chloride will lend itself to the malty profile. With some really acidic grain bills like Stouts, Pickling Lime can be good because it raises calcium and it will lower the acidity at the same time.

I attached two screenshots of the spreadsheet with your grain bill entered into the mash acidification tab, as well as your mash and sparge water quantities (for 100% Distilled water.) You can see I was able to use Gypsum and Calcium Chloride to get the water profile right where it needs to be for this type of beer, while achieving a 5.4 pH, without lactic acid.

 

[murphyslaw]

Wow, I'm not sure why it didn't cross my mind to use the gypsum to balance out the chloride since that also adds the Ca I was targeting. :smack:

Thanks again for taking the time to work through this with me. I think I have a much better understanding of how all of this works.